1
|
Mayi MPA, Antonio-Nkondjio C, Bamou R, Damiani C, Cappelli A, Djiappi-Tchamen B, Djamouko-Djonkam L, Ilbeigi Khamseh Nejad M, Pichler V, Ricci I, Favia G. First detection of kdr L1014F allele in Anopheles ziemanni and Anopheles pharoensis in Cameroon and distribution of the allele in members of the Anopheles gambiae complex. Parasit Vectors 2024; 17:363. [PMID: 39192348 DOI: 10.1186/s13071-024-06420-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/24/2024] [Indexed: 08/29/2024] Open
Abstract
BACKGROUND Knockdown resistance (kdr) is one of the primary resistance mechanisms present in anopheline species. Although this mutation is largely spread across the Anopheles gambiae s.l. members, its prevalence in other species is still not well documented. METHODS The present study investigated the distribution and allelic frequencies of kdr in An. gambiae s.l., An. pharoensis, and An. ziemanni samples collected in 2022 and 2023 in nine sites spread across five ecogeographical settings in Cameroon. Members of the An. gambiae complex were identified molecularly by polymerase chain reaction (PCR). kdr L1014F and L1014S alleles were screened by PCR and confirmed by sequencing. RESULTS An. gambiae (49.9%), An. coluzzii (36.5%), and An. arabiensis (13%) were identified, and the frequency of the kdr L1014F was high in both An. gambiae and An. coluzzii in all sites. The kdr L1014F allele was detected for the first time in 8 out of 14 An. ziemanni samples examined and in 5 out of 22 An. pharoensis samples examined. The kdr L1014S allele was scarce and found only in the heterozygote "RS" state in An. arabiensis and An. gambiae in Yangah and Santchou. CONCLUSIONS The present study sheds light on the rapid expansion of the kdr L1014F allele in malaria vectors in Cameroon and stresses the need for surveillance activities also targeting secondary malaria vectors to improve the control of malaria transmission.
Collapse
Affiliation(s)
- Marie Paul Audrey Mayi
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032, Camerino, Italy
| | - Christophe Antonio-Nkondjio
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Roland Bamou
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Borne Diseases Laboratory of the Research Unit for Biology and Applied Ecology (VBID-RUBAE), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
- Laboratory of Malaria and Vector Research-LMVR, Rockville National Institute of Health /NIAID, Rockville, USA
| | - Claudia Damiani
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, 62032, Camerino, Italy
| | - Alessia Cappelli
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, 62032, Camerino, Italy
| | - Borel Djiappi-Tchamen
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Borne Diseases Laboratory of the Research Unit for Biology and Applied Ecology (VBID-RUBAE), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Landre Djamouko-Djonkam
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
- Vector Borne Diseases Laboratory of the Research Unit for Biology and Applied Ecology (VBID-RUBAE), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - Mahdokht Ilbeigi Khamseh Nejad
- School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, 62032, Camerino, Italy
| | - Verena Pichler
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Irene Ricci
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, 62032, Camerino, Italy
| | - Guido Favia
- School of Biosciences and Veterinary Medicine, University of Camerino, CIRM Italian Malaria Network, Via Gentile III da Varano, 62032, Camerino, Italy.
| |
Collapse
|
2
|
Vajda ÉA, Ross A, Doum D, Fairbanks EL, Chitnis N, Hii J, Moore SJ, Richardson JH, Macdonald M, Sovannaroth S, Kimheng P, McIver DJ, Tatarsky A, Lobo NF. Field evaluation of a volatile pyrethroid spatial repellent and etofenprox treated clothing for outdoor protection against forest malaria vectors in Cambodia. Sci Rep 2024; 14:17348. [PMID: 39069597 PMCID: PMC11284218 DOI: 10.1038/s41598-024-67470-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 07/11/2024] [Indexed: 07/30/2024] Open
Abstract
Cambodia's goal to eliminate malaria by 2025 is challenged by persistent transmission in forest and forest fringe areas, where people are exposed to Anopheles mosquito bites during the day and night. Volatile pyrethroid spatial repellents (VPSRs) and insecticide-treated clothing (ITC) could address these gaps. This study evaluated the outdoor application of one passive transfluthrin-based VPSR, four etofenprox-ITCs paired with a picaridin topical repellent, and a combination of VPSR and ITC against wild Anopheles landing in Cambodia. A 7 × 7 Latin-square study was conducted over 49 collection nights in temporary open structures in Mondulkiri Province. All interventions substantially reduced Anopheles landing, with protective efficacy ranging from 61 to 95%. Mathematical modeling showed significant reductions in vectoral capacity, especially with the combined ITC and VPSR and VPSR alone, albeit with decreased effectiveness over time. These interventions have the potential to reduce outdoor and daytime Anopheles biting, offering valuable contributions to malaria elimination efforts in Cambodia and the Greater Mekong Subregion, contingent upon achieving effective coverage and adherence.
Collapse
Affiliation(s)
- Élodie A Vajda
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA.
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland.
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Dyna Doum
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
- Health Forefront Organization, Phnom Penh, Cambodia
| | - Emma L Fairbanks
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Nakul Chitnis
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Jeffrey Hii
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Sarah J Moore
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
- Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 74, Bagamoyo, Tanzania
| | - Jason H Richardson
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, L3 5QA, UK
| | - Michael Macdonald
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, L3 5QA, UK
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, 477, Phnom Penh, Cambodia
| | - Pen Kimheng
- Department of Health of Mondulkiri, C5XX+CP4, 76, Krong Saen Monourom, Cambodia
| | - David J McIver
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Allison Tatarsky
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Neil F Lobo
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
- University of Notre Dame, Notre Dame, IN, 46556, USA
| |
Collapse
|
3
|
Sovegnon PM, Akoton R, Stopard IJ, Churcher TS, McCall PJ, Ranson H, Foster GM, Djogbénou LS. Efficacy of Interceptor G2, Royal Guard and PermaNet 3.0 against pyrethroid-resistant Anopheles gambiae s.l. from Za-Kpota, southern Benin: an experimental hut trial. Parasit Vectors 2024; 17:300. [PMID: 38992693 PMCID: PMC11238393 DOI: 10.1186/s13071-024-06372-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 06/23/2024] [Indexed: 07/13/2024] Open
Abstract
BACKGROUND The widespread use of insecticide-treated nets (ITNs) has significantly contributed to the reduction in malaria cases and deaths observed across Africa. Unfortunately, this control strategy is threatened by the rapid spread of pyrethroid resistance in malaria vectors. Dual-active-ingredient insecticidal nets are now available to mitigate the impact of pyrethroid resistance. To facilitate evidence-based decisions regarding product selection in specific use settings, data are needed on the efficacy of these different nets against local mosquito populations. METHODS Two experimental hut trials were performed in Za-Kpota, southern Benin in 2021 to evaluate the performance of Interceptor G2 (BASF), Royal Guard (Disease Control Technologies) and PermaNet 3.0 (Vestergaard Frandsen), all dual-active-ingredient bednets, in comparison to untreated or standard pyrethroid-treated bednets, against free-flying wild Anopheles gambiae mosquitoes. The performance of some of these next-generation nets was compared to the same type of nets that have been in use for up to 2 years. Mosquitoes collected in the huts were followed up after exposure to assess the sublethal effects of treatments on certain life-history traits. RESULTS The predominant species in the study site was Anopheles gambiae sensu stricto (An. gambiae s.s.). Both Anopheles coluzzii and An. gambiae s.s. were resistant to pyrethroids (deltamethrin susceptibility was restored by piperonyl butoxide pre-exposure). In the experimental hut trials, the highest blood-feeding inhibition (5.56%) was recorded for the Royal Guard net, relative to the standard PermaNet 2.0 net (44.44% inhibition). The highest 72-h mortality rate (90.11%) was recorded for the Interceptor G2 net compared to the PermaNet 2.0 net (56.04%). After exposure, the risk of death of An. gambiae sensu lato (An. gambiae s.l.) was 6.5-fold higher with the Interceptor G2 net and 4.4-fold higher with the PermaNet 3.0 net compared to the respective untreated net. Lower mosquito mortality was recorded with an aged Interceptor G2 net compared to a new Interceptor G2 net. Oviposition rates were lower in mosquitoes collected from huts containing ITNs compared to those of untreated controls. None of the mosquitoes collected from huts equipped with Royal Guard nets laid any eggs. CONCLUSIONS The Royal Guard and Interceptor G2 nets showed a potential to significantly improve the control of malaria-transmitting vectors. However, the PermaNet 3.0 net remains effective in pyrethroid-resistant areas.
Collapse
Affiliation(s)
- Pierre Marie Sovegnon
- Tropical Infectious Diseases Research Centre (TIDRC), University of Abomey Calavi, Cotonou, Benin.
| | - Romaric Akoton
- Tropical Infectious Diseases Research Centre (TIDRC), University of Abomey Calavi, Cotonou, Benin
| | - Isaac J Stopard
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Faculty of Medicine, Imperial College London, London, UK
| | - Philip J McCall
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Geraldine M Foster
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Luc Salako Djogbénou
- Tropical Infectious Diseases Research Centre (TIDRC), University of Abomey Calavi, Cotonou, Benin
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| |
Collapse
|
4
|
Sima-Biyang YV, Ontoua SS, Longo-Pendy NM, Mbou-Boutambe C, Makouloutou-Nzassi P, Moussadji CK, Lekana-Douki JB, Boundenga L. Epidemiology of malaria in Gabon: A systematic review and meta-analysis from 1980 to 2023. J Infect Public Health 2024; 17:102459. [PMID: 38870682 DOI: 10.1016/j.jiph.2024.05.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 05/13/2024] [Accepted: 05/22/2024] [Indexed: 06/15/2024] Open
Abstract
The objective of this were conducted to elucidate spatiotemporal variations in malaria epidemiology in Gabon since 1980. For that, five databases, were used to collect and identify all studies published between 1980 and 2023 on malaria prevalence, antimalarial drug resistance, markers of antimalarial drug resistance and insecticide resistance marker. The findings suggest that Gabon continues to face malaria as an urgent public health problem, with persistently high prevalence rates. Markers of resistance to CQ persist despite its withdrawal, and markers of resistance to SP have emerged with a high frequency, reaching 100 %, while ACTs remain effective. Also, recent studies have identified markers of resistance to the insecticides Kdr-w and Kdr-e at frequencies ranging from 25 % to 100 %. Ace1R mutation was reported with a frequency of 0.4 %. In conclusion, the efficacy of ACTs remains above the threshold recommended by the WHO. Organo-phosphates and carbamates could provide an alternative for vector control.
Collapse
Affiliation(s)
- Yann Vital Sima-Biyang
- Unit of Research in Ecology of Health (URES), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon; Central African Regional Doctoral School in Tropical Infectiology (EDR), BP 876 Franceville, Gabon
| | - Steede Seinnat Ontoua
- Central African Regional Doctoral School in Tropical Infectiology (EDR), BP 876 Franceville, Gabon; Unit of Evolution, Epidemiology and Parasite Resistance (UNEEREP), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon
| | - Neil Michel Longo-Pendy
- Unit of Research in Ecology of Health (URES), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon
| | - Clark Mbou-Boutambe
- Unit of Research in Ecology of Health (URES), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon; Central African Regional Doctoral School in Tropical Infectiology (EDR), BP 876 Franceville, Gabon
| | - Patrice Makouloutou-Nzassi
- Unit of Research in Ecology of Health (URES), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon; Department of Animal Biology and Ecology, Tropical Ecology Research Institute (IRET/CENAREST), Libreville BP 13354, Gabon
| | - Cyr Kinga Moussadji
- Primatology Center, Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon
| | - Jean-Bernard Lekana-Douki
- Unit of Evolution, Epidemiology and Parasite Resistance (UNEEREP), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon; Department of Parasitology-Mycology-Tropical Medicine, University of Health Sciences, Faculty of Medicine, BP 4009 Libreville, Gabon
| | - Larson Boundenga
- Unit of Research in Ecology of Health (URES), Franceville Interdisciplinary Center for Medical Research (CIRMF), BP 769 Franceville, Gabon; Department of Anthropology, Durham University, South Road, Durham DH1 3LE, UK.
| |
Collapse
|
5
|
Kamau L, Bennett KL, Ochomo E, Herren J, Agumba S, Otieno S, Omoke D, Matoke-Muhia D, Mburu D, Mwangangi J, Ramaita E, Juma EO, Mbogo C, Barasa S, Miles A. The Anopheles coluzzii range extends into Kenya: detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa. Malar J 2024; 23:122. [PMID: 38671462 PMCID: PMC11046809 DOI: 10.1186/s12936-024-04950-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. The current study sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well as describe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzii populations. METHODS Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa. RESULTS This study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya. CONCLUSIONS These findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
Collapse
Affiliation(s)
- Luna Kamau
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute, PO Box 54840, Nairobi, 00200, Kenya.
| | - Kelly L Bennett
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Eric Ochomo
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jeremy Herren
- International Center for Insect Physiology and Ecology (Icipe), Nairobi, Kenya
| | - Silas Agumba
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Samson Otieno
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Diana Omoke
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute, Nairobi, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute, PO Box 54840, Nairobi, 00200, Kenya
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - David Mburu
- Pwani University Biosciences Research Centre (PUBReC), Kilifi, Kenya
| | - Joseph Mwangangi
- Centre for Geographic Medicine Research-Coast (CGMR-C), Kenya Medical Research Institute, Nairobi, Kenya
| | - Edith Ramaita
- Ministry of Health-National Malaria Control Programme (NMCP), Kenya, Nairobi, Kenya
| | - Elijah O Juma
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Charles Mbogo
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Sonia Barasa
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
- Pan African Mosquito Control Association (PAMCA), Nairobi, Kenya
| | - Alistair Miles
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| |
Collapse
|
6
|
Boussougou-Sambe ST, Ngossanga B, Doumba-Ndalembouly AG, Boussougou LN, Woldearegai TG, Mougeni F, Mba TN, Edoa JR, Dejon-Agobé JC, Awono-Ambene P, Kremsner PG, Kenguele HM, Borrmann S, Mordmüller B, Adegnika AA. Anopheles gambiae s.s. resistance to pyrethroids and DDT in semi-urban and rural areas of the Moyen-Ogooué Province, Gabon. Malar J 2023; 22:382. [PMID: 38110952 PMCID: PMC10729327 DOI: 10.1186/s12936-023-04820-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/12/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Pyrethroids are the main insecticides used in vector control for malaria. However, their extensive use in the impregnation of long-lasting insecticidal nets (LLINs) and indoor residual spraying has led to the development of resistance, threatening its success as a tool for malaria control. Baseline data prior to large scale distribution of LLINs are important for the implementation of efficient strategies. However, no data on the susceptibility of malaria vectors is available in the Moyen-Ogooué Province in Gabon. The aim of this study was to assess the susceptibility to pyrethroids and organochlorides of malaria vectors from a semi-urban and rural areas of the province and to determine the frequency of insecticide resistance genes. METHODS Larvae were collected from breeding sites in Lambaréné and Zilé and reared to adults. Three to five-day old female Anopheles gambiae sensu lato mosquitoes were used in cone tube assays following the WHO susceptibility tests protocol for adult mosquitoes. A subsample was molecularly identified using the SINE200 protocol and the frequency of Vgsc-1014 F and - 1014 S mutations were determined. RESULTS Anopheles gambiae sensu stricto (s.s.) was the sole species present in both Lambaréné and Zilé. Mosquito populations from the two areas were resistant to pyrethroids and organochlorides. Resistance was more pronounced for permethrin and DDT with mortality lower than 7% for both insecticides in the two study areas. Mosquitoes were statistically more resistant (P < 0.0001) to deltamethrin in Lambaréné (51%) compared to Zilé (76%). All the mosquitoes tested were heterozygous or homozygous for the knockdown resistance (Kdr) mutations Vgsc-L1014F and Vgsc-L1014S with a higher proportion of Vgsc-L1014F homozygous in Lambaréné (76.7%) compared to Zilé (57.1%). CONCLUSION This study provides evidence of widespread resistance to pyrethroids in An. gambiae s.s., the main malaria vector in the Moyen-Ogooué Province. Further investigation of the mechanisms underlining the resistance of An. gambiae s.s. to pyrethroids is needed to implement appropriate insecticide resistance management strategies.
Collapse
Affiliation(s)
| | | | | | | | - Tamirat Gebru Woldearegai
- Institut für Tropenmedizin, Eberhard-Karls-Universität, Tübingen, Germany
- German Center for Infection Research (DZIF), Partner Site, Tübingen, Germany
| | - Fabrice Mougeni
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | | | | | - Parfait Awono-Ambene
- Institut de Recherche de Yaoundé, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität, Tübingen, Germany
- German Center for Infection Research (DZIF), Partner Site, Tübingen, Germany
| | | | - Steffen Borrmann
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität, Tübingen, Germany
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität, Tübingen, Germany
- Department of Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Ayôla Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität, Tübingen, Germany
- German Center for Infection Research (DZIF), Partner Site, Tübingen, Germany
- Fondation pour la Recherche Scientifique (FORS), Cotonou, Benin
| |
Collapse
|
7
|
Afrane YA, Abdulai A, Mohammed AR, Akuamoah-Boateng Y, Owusu-Asenso CM, Sraku IK, Yanney SA, Malm K, Lobo NF. First detection of Anopheles stephensi in Ghana using molecular surveillance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569589. [PMID: 38076990 PMCID: PMC10705536 DOI: 10.1101/2023.12.01.569589] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The invasive Anopheles stephensi mosquito has been rapidly expanding in range in Africa over the last decade, spreading from the Indian sub-continent to several East African countries (Djibouti, Ethiopia, Sudan, Somalia and Kenya) and now in West Africa, Nigeria. The rapid expansion of this invasive vector poses a major threat to current malaria control and elimination efforts. In line with the WHO's strategy to stop the spread of this invasive species by enhancing surveillance and control measures in Africa, we incorporated morphological and molecular surveillance of An. stephensi into routine entomological surveillance of malaria vectors in the city of Accra, Ghana. Here, we report on the first detection of An. stephensi in Ghana. An. stephensi mosquitoes were confirmed using PCR and sequencing of the ITS2 regions. These findings highlight the urgent need for increased surveillance and response strategies to mitigate the spread of An. stephensi in Ghana.
Collapse
|
8
|
Liu K, Ma S, Zhang K, Gao R, Jin H, Cao P, Yuchi Z, Wu S. Functional Characterization of Knockdown Resistance Mutation L1014S in the German Cockroach, Blattella germanica (Linnaeus). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:2734-2744. [PMID: 36701428 DOI: 10.1021/acs.jafc.2c05625] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The effectiveness of pyrethroid insecticides is seriously threatened by knockdown resistance (kdr), which is induced in insects by inherited single-nucleotide polymorphisms in the voltage-gated sodium channel (VGSC) gene. VGSC's L1014F substitution results in the classic kdr mutation, which is found in many pest species. Other substitutions of the L1014 locus, such as L1014S, L1014C, L1014W, and L1014H, were also reported. In 2022, a new amino acid substitute L1014S of Blattella germanica was first discovered in China. We modified the BgNav1-1 sodium channel from cockroaches with the L1014S mutation to study how pyrethroid sensitivity and channel gating were affected in Xenopus oocytes. The L1014S mutation reduced the half-maximal activation voltage (V1/2,act) from -19.0 (wild type) to -15.5 mV while maintaining the voltage dependency of activation. Moreover, the voltage dependence of inactivation in the hyperpolarizing shifts from -48.3 (wild type) to -50.9 mV. However, compared with wild type, the mutation L1014S did not cause a significant shift in the half activation voltage (V1/2,act). Notably, the voltage dependency of activation was unaffected greatly by the L1014S mutation. Tail currents are induced by two types of pyrethroids (1 μM): type I (permethrin, bifenthrin) and type II (deltamethrin, λ-cyhalothrin). All four pyrethroids produced tail currents, and significant differences were found in the percentages of channel modifications between variants and wild types. Further computer modeling showed that the L1014S mutation allosterically modifies pyrethroid binding and action on B. germanica VGSC, with some residues playing a critical role in pyrethroid binding. This study elucidated the pyrethroid resistance mechanism of B. germanica and predicted the residues that may confer the risk of pyrethroid resistance, providing a molecular basis for understanding the resistance mechanisms conferred by mutations at the 1014 site in VGSC.
Collapse
Affiliation(s)
- Kaiyang Liu
- Sanya Nanfan Research Institute, Hainan University, Sanya572024, China
- College of Tropical Crops, Hainan University, Haikou570228, China
| | - Shuyue Ma
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin University, Tianjin30072, China
| | - Kun Zhang
- Sanya Nanfan Research Institute, Hainan University, Sanya572024, China
- College of Plant Protection, Hainan University, Haikou570228, China
| | - Ruibo Gao
- Sanya Nanfan Research Institute, Hainan University, Sanya572024, China
- College of Plant Protection, Hainan University, Haikou570228, China
| | - Haifeng Jin
- Sanya Nanfan Research Institute, Hainan University, Sanya572024, China
- College of Plant Protection, Hainan University, Haikou570228, China
| | - Peng Cao
- Key Laboratory of Drug Targets and Drug Leads for Degenerative Diseases, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing210023, China
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin University, Tianjin30072, China
| | - Shaoying Wu
- Sanya Nanfan Research Institute, Hainan University, Sanya572024, China
- College of Plant Protection, Hainan University, Haikou570228, China
| |
Collapse
|
9
|
Pollegioni P, Persampieri T, Minuz RL, Bucci A, Trusso A, Martino SD, Leo C, Bruttini M, Ciolfi M, Waldvogel A, Tripet F, Simoni A, Crisanti A, Müller R. Introgression of a synthetic sex ratio distortion transgene into different genetic backgrounds of Anopheles coluzzii. INSECT MOLECULAR BIOLOGY 2023; 32:56-68. [PMID: 36251429 PMCID: PMC10092091 DOI: 10.1111/imb.12813] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
The development of genetically modified mosquitoes (GMM) and their subsequent field release offers innovative approaches for vector control of malaria. A non-gene drive self-limiting male-bias Ag(PMB)1 strain has been developed in a 47-year-old laboratory G3 strain of Anopheles gambiae s.l. When Ag(PMB)1 males are crossed to wild-type females, expression of the endonuclease I-PpoI during spermatogenesis causes the meiotic cleavage of the X chromosome in sperm cells, leading to fertile offspring with a 95% male bias. However, World Health Organization states that the functionality of the transgene could differ when inserted in different genetic backgrounds of Anopheles coluzzii which is currently a predominant species in several West-African countries and thus a likely recipient for a potential release of self-limiting GMMs. In this study, we introgressed the transgene from the donor Ag(PMB)1 by six serial backcrosses into two recipient colonies of An. coluzzii that had been isolated in Mali and Burkina Faso. Scans of informative Single Nucleotide Polymorphism (SNP) markers and whole-genome sequencing analysis revealed a nearly complete introgression of chromosomes 3 and X, but a remarkable genomic divergence in a large region of chromosome 2 between the later backcrossed (BC6) transgenic offspring and the recipient paternal strains. These findings suggested to extend the backcrossing breeding strategy beyond BC6 generation and increasing the introgression efficiency of critical regions that have ecological and epidemiological implications through the targeted selection of specific markers. Disregarding differential introgression efficiency, we concluded that the phenotype of the sex ratio distorter is stable in the BC6 introgressed An. coluzzii strains.
Collapse
Affiliation(s)
- Paola Pollegioni
- Research Institute on Terrestrial EcosystemsNational Research CouncilTerniItaly
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Tania Persampieri
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Roxana L. Minuz
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Alessandro Bucci
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Alessandro Trusso
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Salvatore Di Martino
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Chiara Leo
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Marco Bruttini
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
- Tuscan Centre of Precision Medicine, Department of Medicine, Surgery and NeurosciencesUniversity of SienaSienaItaly
| | - Marco Ciolfi
- Research Institute on Terrestrial EcosystemsNational Research CouncilTerniItaly
| | | | - Frédéric Tripet
- Centre for Applied Entomology and ParasitologyKeele UniversityNewcastle‐under‐LymeUK
| | - Alekos Simoni
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
| | - Andrea Crisanti
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | - Ruth Müller
- Genetics and Ecology Research CentrePolo d'Innovazione di Genomica, Genetica e BiologiaTerniItaly
- Unit Entomology, Department of Biomedical SciencesInstitute of Tropical MedicineAntwerpBelgium
| |
Collapse
|
10
|
Ilombe G, Matangila JR, Lulebo A, Mutombo P, Linsuke S, Maketa V, Mabanzila B, Wat'senga F, Van Bortel W, Fiacre A, Irish SR, Lutumba P, Van Geertruyden JP. Malaria among children under 10 years in 4 endemic health areas in Kisantu Health Zone: epidemiology and transmission. Malar J 2023; 22:3. [PMID: 36604663 PMCID: PMC9814333 DOI: 10.1186/s12936-022-04415-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The Democratic Republic of the Congo (DRC) is the second most malaria-affected country in the world with 21,608,681 cases reported in 2019. The Kongo Central (KC) Province has a malaria annual incidence of 163 cases/per 1000 inhabitants which are close to the national average of 153.4/1000. However, the malaria prevalence varies both between and within health zones in this province. The main objective of this study was to describe the epidemiology and transmission of malaria among children aged 0 to 10 years in the 4 highest endemic health areas in Kisantu Health Zone (HZ) of KC in DRC. METHODS A community-based cross-sectional study was conducted from October to November 2017 using multi-stage sampling. A total of 30 villages in 4 health areas in Kisantu HZ were randomly selected. The prevalence of malaria was measured using a thick blood smear (TBS) and known predictors and associated outcomes were assessed. Data are described and association determinants of malaria infection were analysed. RESULTS A total of 1790 children between 0 and 10 years were included in 30 villages in 4 health areas of Kisantu HZ. The overall prevalence in the study area according to the TBS was 14.8% (95% CI: 13.8-16.6; range: 0-53). The mean sporozoite rate in the study area was 4.3% (95% CI: 2.6-6.6). The determination of kdr-west resistance alleles showed the presence of both L1014S and L1014F with 14.6% heterozygous L1014S/L1014F, 84.4% homozygous 1014F, and 1% homozygous 1014S. The risk factors associated with malaria infection were ground or wooden floors aOR: 15.8 (95% CI: 8.6-29.2), a moderate or severe underweight: 1.5 (1.1-2.3) and to be overweight: 1.9 (95% CI: 1.3-2.7). CONCLUSION Malaria prevalence differed between villages and health areas within the same health zone. The control strategy activities must be oriented by the variety in the prevalence and transmission of malaria in different areas. The policy against malaria regarding long-lasting insecticidal nets should be based on the evidence of metabolic resistance.
Collapse
Affiliation(s)
- Gillon Ilombe
- Unit of Entomology, Department of Parasitology, National Institute of Biomedical Research, Kinshasa, Democratic Republic of the Congo.
- Unit of Clinical Pharmacology and Pharmacovigilance, Department of Base Science, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.
- Global Health Institute, Antwerp University, Antwerp, Belgium.
| | - Junior Rika Matangila
- Department of Tropical Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Aimee Lulebo
- Faculty of Medicine, Public Health School, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Paulin Mutombo
- Faculty of Medicine, Public Health School, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Sylvie Linsuke
- Global Health Institute, Antwerp University, Antwerp, Belgium
- Department of Epidemiology Kinshasa, National Institute of Biomedical Research, Kinshasa, Democratic Republic of the Congo
| | - Vivi Maketa
- Department of Tropical Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Baby Mabanzila
- Department of Tropical Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Francis Wat'senga
- Unit of Entomology, Department of Parasitology, National Institute of Biomedical Research, Kinshasa, Democratic Republic of the Congo
| | - Wim Van Bortel
- Unit of Entomology and Outbreak Research Team, Unit of Entomology, Institute of Tropical Medicine, Antwerp, Belgium
| | - Agossa Fiacre
- PMI VectorLink Project, Abt Associates, Kinshasa, Democratic Republic of the Congo
| | - Seth R Irish
- Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, President's Malaria Initiative and Entomology Branch, Atlanta, GA, USA
| | - Pascal Lutumba
- Department of Tropical Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | |
Collapse
|
11
|
Soumaila H, Hamani B, Arzika II, Soumana A, Daouda A, Daouda FA, Iro SM, Gouro S, Zaman-Allah MS, Mahamadou I, Kadri S, Salé NM, Hounkanrin W, Mahamadou B, Zamaka HN, Labbo R, Laminou IM, Jackou H, Idrissa S, Coulibaly E, Bahari-Tohon Z, Mathieu E, Carlson J, Dotson E, Awolola TS, Flatley C, Chabi J. Countrywide insecticide resistance monitoring and first report of the presence of the L1014S knock down resistance in Niger, West Africa. Malar J 2022; 21:385. [PMID: 36522727 PMCID: PMC9756763 DOI: 10.1186/s12936-022-04410-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Mass distribution of insecticide-treated nets (ITNs) is the principal malaria vector control strategy adopted by Niger. To better inform on the most appropriate ITN to distribute, the National Malaria Control Programme (NMCP) of Niger and its partners, conducted insecticide resistance monitoring in selected sites across the country. METHODS The susceptibility of Anopheles gambiae sensu lato (s.l.) to chlorfenapyr and pyrethroid insecticides was investigated in a total of sixteen sites in 2019 and 2020, using 2-5-day-old adults reared from wild collected larvae per site. The susceptibility status, pyrethroid resistance intensity at 5 and 10 times the diagnostic concentrations, and piperonyl butoxide (PBO) synergism with diagnostic concentrations of deltamethrin, permethrin and alpha-cypermethrin were assessed using WHO bioassays. Two doses (100 and 200 µg/bottle) of chlorfenapyr were tested using the CDC bottle assay method. Species composition and allele frequencies for knock-down resistance (kdr-L1014F and L1014S) and acetylcholinesterase (ace-1 G119S) mutations were further characterized using polymerase chain reaction (PCR). RESULTS High resistance intensity to all pyrethroids tested was observed in all sites except for alpha-cypermethrin in Gaya and Tessaoua and permethrin in Gaya in 2019 recording moderate resistance intensity. Similarly, Balleyara, Keita and Tillabery yielded moderate resistance intensity for alpha-cypermethrin and deltamethrin, and Niamey V low resistance intensity against deltamethrin and permethrin in 2020. Pre-exposure to PBO substantially increased susceptibility with average increases in mortality between 0 and 70% for tested pyrethroids. Susceptibility to chlorfenapyr (100 µg/bottle) was recorded in all sites except in Tessaoua and Magaria where susceptibility was recorded at the dose of 200 µg/bottle. Anopheles coluzzii was the predominant malaria vector species in most of the sites followed by An. gambiae sensu stricto (s.s.) and Anopheles arabiensis. The kdr-L1014S allele, investigated for the first time, was detected in the country. Both kdr-L1014F (frequencies [0.46-0.81]) and L1014S (frequencies [0.41-0.87]) were present in all sites while the ace-1 G119S was between 0.08 and 0.20. CONCLUSION The data collected will guide the NMCP in making evidence-based decisions to better adapt vector control strategies and insecticide resistance management in Niger, starting with mass distribution of new generation ITNs such as interceptor G2 and PBO ITNs.
Collapse
Affiliation(s)
| | - Boubé Hamani
- National Malaria Control Programme, Niamey, Niger
| | | | - Amadou Soumana
- grid.452260.7Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | | | | | | | - Samira Gouro
- National Malaria Control Programme, Niamey, Niger
| | | | - Izamné Mahamadou
- grid.452260.7Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Saadou Kadri
- grid.452260.7Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Noura Maman Salé
- grid.452260.7Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | | | | | | | - Rabiou Labbo
- grid.452260.7Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | | | | | | | - Eric Coulibaly
- U.S. President’s Malaria Initiative, USAID, Niamey, Niger
| | | | - Els Mathieu
- U.S. President’s Malaria Initiative, USAID, Niamey, Niger ,grid.416738.f0000 0001 2163 0069U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Jenny Carlson
- grid.507606.2Entomology Branch, U.S. President’s Malaria Initiative, Atlanta, GA USA
| | - Ellen Dotson
- grid.416738.f0000 0001 2163 0069U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Taiwo Samson Awolola
- grid.416738.f0000 0001 2163 0069U.S. Centers for Disease Control and Prevention, Atlanta, GA USA
| | | | - Joseph Chabi
- grid.507606.2PMI VectorLink Project, Washington, DC USA
| |
Collapse
|
12
|
Mbakop LR, Awono-Ambene PH, Ekoko WE, Mandeng SE, Nwane P, Fesuh BN, Toto JC, Alenou LD, Onguina HG, Piameu M, Fomena A, Etang J. Malaria Transmission and Vector Resistance to Insecticides in a Changing Environment: Case of Simbock in Yaoundé-City, Cameroon. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.902211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ecological upheavals resulting from uncontrolled urbanization can lead to significant changes in vector borne diseases’ profiles, thus requiring a thorough revision of their prevention and control strategies. The current study aimed at characterizing malaria vector populations in the Simbock neighborhood of Yaoundé-city (Cameroon), in relation to its urbanization scheme. Adult mosquitoes were captured by human landing catches (HLC) in- and outdoors prior to (2000–2006) and during infrastructural development (2014–2016). Anophelines were morphologically identified and analyzed for Plasmodium (P.) falciparum circumsporozoite protein detection using the ELISA technique. Species of the Anopheles (An.) gambiae complex were identified using SINE-PCR. Adult An. gambiae s.l. from larvae collected between 2014 and 2017 were tested for susceptibility to insecticides (0.1% bendiocarb, 4% DDT, 0.75% permethrin and 0.05% deltamethrin) with or without piperonyl butoxide (PBO) synergist, using WHO standard bioassays. The Hot Oligonucleotide Ligation Assay was used to detect the knockdown resistance (kdr) L995F/S mutations. Overall, nine malaria vector species were identified in 2000-2006, mostly An. moucheti (49%), An. nili (13.5%) and An. gambiae s.l. (12%); the six remaining species were represented at less than 3% each. However, only three species were found in 2014-2016, with increasing proportions of An. gambiae s.l. (67%) and An. funestus (32%) (P<0.0001). An. gambiae s.l. consisted An. coluzzii (> 85%) and An. gambiae (<15%) species during the two study periods. Plasmodium falciparum infection rates were 2.1% and 1.0% in 2000-2006 and 2014-2016 respectively (P=0.4), with decreasing entomological inoculation rates (EIR) from 0.34 infective bites per man per night (ib/m/n) to 0.02 ib/m/n (P<0.0001). Anopheles gambiae s.l. was resistant to DDT and permethrin [<40% mortality rates (MR)], and deltamethrin (65-89% MR), but fully susceptible to bendiocarb (100% MR). Pre-exposure of mosquitoes to PBO resulted in 90-100% MR to deltamethrin but not to permethrin. Furthermore, the two kdr L995F/S resistance alleles were recorded at 0.64 and 0.006 frequencies respectively. This study highlights a shift from rural to urban malaria transmission in Simbock, coupled with DDT and pyrethroid resistance in An. gambiae s.l. Combination vector control interventions, e.g., PBO nets and bendiocarb indoor residual spraying are needed in such areas.
Collapse
|
13
|
Boussougou-Sambe ST, Woldearegai TG, Doumba-Ndalembouly AG, Ngossanga B, Mba RB, Edoa JR, Zinsou JF, Honkpehedji YJ, Ngoa UA, Dejon-Agobé JC, Borrmann S, Kremsner PG, Mordmüller B, Adegnika AA. Assessment of malaria transmission intensity and insecticide resistance mechanisms in three rural areas of the Moyen Ogooué Province of Gabon. Parasit Vectors 2022; 15:217. [PMID: 35725630 PMCID: PMC9208124 DOI: 10.1186/s13071-022-05320-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/10/2022] [Indexed: 12/03/2022] Open
Abstract
Background Vector control is considered to be the most successful component of malaria prevention programs and a major contributor to the reduction of malaria incidence over the last two decades. However, the success of this strategy is threatened by the development of resistance to insecticides and behavioural adaptations of vectors. The aim of this study was to monitor malaria transmission and the distribution of insecticide resistance genes in Anopheles populations from three rural areas of the Moyen Ogooué Province of Gabon. Methods Anopheles spp. were collected using human landing catches in Bindo, Nombakélé and Zilé, three villages located in the surroundings of Lambaréné, during both the rainy and dry seasons. Mosquitoes were identified morphologically, and DNA was extracted from heads and thoraces. Members of the Anopheles gambiae complex were identified by molecular methods using the PCR SINE200 protocol and by sequencing of the internal transcribed spacer 2 region. Taqman assays were used to determine Plasmodium infection and the presence of resistance alleles. Results Anopheles gambiae sensu lato (97.7%), An. moucheti (1.7%) and An. coustani (0.6%) were the three groups of species collected. Anopheles gambiae sensu stricto (98.5%) and An. coluzzii (1.5%) were the only species of the An. gambiae complex present in the collection. Of the 1235 Anopheles collected, 1193 were collected during the rainy season; these exhibited an exophagic behaviour, and consistently more mosquitoes were collected outdoor than indoor in the three study areas. Of the 1166 Anopheles screened, 26 (2.2%) were infected with Plasmodium species, specifically Plasmodium falciparum (66.7%), P. malariae (15.4%), P. ovale curtisi (11.5%) and P. ovale wallikeri (3.8%). Malaria transmission intensity was high in Zilé, with an average annual entomological inoculation rate (aEIR) of 243 infective bites per year, while aEIRs in Bindo and Nombakélé were 80.2 and 17 infective bites per year, respectively. Both the L1014F and L1014S mutations were present at frequencies > 95% but no Ace1G119S mutation was found. Conclusion Our results demonstrate that malaria transmission intensity is heterogeneous in these three rural areas of Moyen Ogooué Province, with areas of high transmission, such as Zilé. The exophagic behaviour of the mosquitoes as well as the high frequency of resistance mutations are serious challenges that need to be addressed by the deployment of control measures adapted to the local setting. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05320-9.
Collapse
Affiliation(s)
| | - Tamirat Gebru Woldearegai
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | | | | | - Romuald Beh Mba
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Jeannot Fréjus Zinsou
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Yabo Josiane Honkpehedji
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands.,Fondation pour la Recherche Scientifique (FORS), Cotonou, Benin
| | | | - Jean Claude Dejon-Agobé
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, the Netherlands
| | - Steffen Borrmann
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany
| | - Peter G Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany.,Department of Medical Microbiology, Radboud University Medical Center (UMC), 6524 GA, Nijmegen, The Netherlands
| | - Ayôla A Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.,Institut für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany.,Fondation pour la Recherche Scientifique (FORS), Cotonou, Benin
| |
Collapse
|
14
|
Kpanou CD, Sagbohan HW, Sovi A, Osse R, Padonou GG, Salako A, Tokponnon F, Fassinou AJ, Yovogan B, Nwangwu UC, Adoha CJ, Odjo EM, Ahogni I, Sidick A, Saïd Baba-Moussa L, Akogbéto M. Assessing Insecticide Susceptibility and Resistance Intensity of Anopheles gambiae s.l. Populations From Some Districts of Benin Republic, West Africa. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:949-956. [PMID: 35357491 DOI: 10.1093/jme/tjac037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Indexed: 06/14/2023]
Abstract
Pyrethroid resistance is widespread in sub-Saharan Africa. The objective of this study was to assess the insecticide resistance intensity in Anopheles gambiae s.l. (Diptera: Culicidae) in four districts of Benin in order to better understand how pyrethroid-only nets are likely to be effective. Thus, adult females of An. gambiae s.l., reared from field-collected larvae were used for assessing resistance intensity to permethrin and deltamethrin. They were tested at 1×, 5×, and 10× the diagnostic dose, using both WHO susceptibility tube testing and CDC bottle bioassays. Identification of molecular species, as well as of L1014F Kdr and Ace-1R mutations was performed using the PCR. The level of expression of biochemical enzymes was also evaluated. Overall, moderate to high resistance intensity to permethrin and deltamethrin was observed, irrespective of the testing method. While the L1014F Kdr frequency was high (>75%), Ace-1R was low (≤6%) in An. gambiaes.s. and Anopheles coluzzii, the two predominant species [52% (95% CI: 44.8-59.1) and 45% (95% CI: 38.0-52.2), respectively]. Anopheles arabiensis was found at very low frequency (3%, 95%CI: 1.1-6.4). For Biochemical analyses, α and β-esterases were over-expressed in all four districts, while mixed-function oxidases (MFOs) were over-expressed in only one. Overall, the two testing methods led to comparable conclusions, though there were a few inconsistencies between them. The moderate-high resistance intensity observed in the study area suggests that dual active-ingredient (AI) long-lasting insecticidal nets (LLINs) may provide better control of insecticide-resistant mosquitoes.
Collapse
Affiliation(s)
- Casimir Dossou Kpanou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Hermann W Sagbohan
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Arthur Sovi
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Department of Sciences and Techniques for Animal and Fisheries Production, Faculty of Agronomy, University of Parakou, BP 123 Parakou, Benin
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HT, UK
| | - Razaki Osse
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département des Sciences Animales et Halieutiques, École de gestion et d'exploitation des systèmes d'élevage, Université Nationale d'Agriculture de Porto-Novo, BP 43 Kétou, Bénin
| | - Gil G Padonou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Albert Salako
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Filémon Tokponnon
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Arsène Jacques Fassinou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Boulais Yovogan
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Udoka C Nwangwu
- Department of Disease Surveillance, National Arbovirus and Vectors Research Centre (NAVRC), 4 Park Ave, GRA 400102, Enugu, Nigeria
| | - Constantin J Adoha
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Esdras Mahoutin Odjo
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Idelphonse Ahogni
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Aboubakar Sidick
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Lamine Saïd Baba-Moussa
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Martin Akogbéto
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| |
Collapse
|
15
|
Chanyalew T, Natea G, Amenu D, Yewhalaw D, Simma EA. Composition of mosquito fauna and insecticide resistance status of Anopheles gambiae sensu lato in Itang special district, Gambella, Southwestern Ethiopia. Malar J 2022; 21:125. [PMID: 35436961 PMCID: PMC9014582 DOI: 10.1186/s12936-022-04150-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/04/2022] [Indexed: 11/10/2022] Open
Abstract
Background Anopheles arabiensis, member species of the Anopheles gambiae complex, is the primary vector of malaria and is widely distributed in Ethiopia. Anopheles funestus, Anopheles pharoensis and Anopheles nili are secondary vectors occurring with limited distribution in the country. Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are pillars for the interventions against malaria control and elimination efforts in Ethiopia. However, the emergence and widespread of insecticide resistance in An. gambiae sensu lato (s.l.), might compromise the control efforts of the country. The aim of this study was to investigate composition of mosquito fauna and insecticide resistance status of An. gambiae s.l. in Itang special district ( woreda), Gambella, southwestern Ethiopia. Methods Adult mosquitoes were sampled from September 2020 to February 2021 using the CDC light trap and pyrethrum spray catch (PSC). CDC light traps were placed in three selected houses for two consecutive days per month to collect mosquitoes indoor and outdoor from 6:00 P.M. to 06:00 A.M. and PSC was used to collect indoor resting mosquitoes from ten selected houses once in a month from October 2020 to February 2021. Moreover, mosquito larvae were also collected from different breeding sites and reared to adults to assess susceptibility status of populations of An. gambiae s.l. in the study area. Susceptibility tests were conducted on two to three days old non blood fed female An. gambiae s.l. using insecticide impregnated papers with deltamethrin (0.05%), alpha-cypermethrin (0.05%), propoxur (0.1%), pirimiphos-methyl (0.25%) and bendiocarb (0.1%) following World Health Organization (WHO) standard susceptibility test procedure. Molecular diagnostics were done for the identification of member species of An. gambiae s.l. and detection of knockdown resistance (kdr) allele using species specific polymerase chain reaction (PCR) and allele specific PCR. Results In total, 468 adult mosquitoes were collected from different houses. Culex mosquitoes were the most dominant (80.4%) followed by Anopheles mosquitoes. Three species of Anopheles (Anopheles coustani, An. pharoensis, and An. gambiae s.l.) were identified, of which An. coustani was the dominant (8.1%) species. Higher number of mosquitoes (231) were collected outdoor by CDC light traps. Out of 468 adult mosquitoes, 294 were blood fed, 46 were half-gravid and gravid whereas the remaining 128 were unfed. WHO bioassay tests revealed that the populations of An. gambiae s.l. in the study area are resistant against alpha-cypermethrin and deltamethrin, but susceptible to bendiocarb, pirimiphos-methyl and propoxur. Of the total 86 An. gambiae s.l. specimens assayed, 79 (92%) successfully amplified and identified as An. arabiensis. West African kdr (L1014F) mutation was detected with high kdr allele frequency ranging from 67 to 88%. Conclusion The detection of target site mutation, kdr L1014F allele, coupled with the phenotypic resistance against alpha-cypermethrin and deltamethrin call for continuous resistance monitoring.
Collapse
|
16
|
Vargas-Chavez C, Longo Pendy NM, Nsango SE, Aguilera L, Ayala D, González J. Transposable element variants and their potential adaptive impact in urban populations of the malaria vector Anopheles coluzzii. Genome Res 2021; 32:189-202. [PMID: 34965939 PMCID: PMC8744685 DOI: 10.1101/gr.275761.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 11/24/2021] [Indexed: 11/28/2022]
Abstract
Anopheles coluzzii is one of the primary vectors of human malaria in sub-Saharan Africa. Recently, it has spread into the main cities of Central Africa threatening vector control programs. The adaptation of An. coluzzii to urban environments partly results from an increased tolerance to organic pollution and insecticides. Some of the molecular mechanisms for ecological adaptation are known, but the role of transposable elements (TEs) in the adaptive processes of this species has not been studied yet. As a first step toward assessing the role of TEs in rapid urban adaptation, we sequenced using long reads six An. coluzzii genomes from natural breeding sites in two major Central Africa cities. We de novo annotated TEs in these genomes and in an additional high-quality An. coluzzii genome, and we identified 64 new TE families. TEs were nonrandomly distributed throughout the genome with significant differences in the number of insertions of several superfamilies across the studied genomes. We identified seven putatively active families with insertions near genes with functions related to vectorial capacity, and several TEs that may provide promoter and transcription factor binding sites to insecticide resistance and immune-related genes. Overall, the analysis of multiple high-quality genomes allowed us to generate the most comprehensive TE annotation in this species to date and identify several TE insertions that could potentially impact both genome architecture and the regulation of functionally relevant genes. These results provide a basis for future studies of the impact of TEs on the biology of An. coluzzii.
Collapse
Affiliation(s)
- Carlos Vargas-Chavez
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), 08003 Barcelona, Spain
| | - Neil Michel Longo Pendy
- Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville, Gabon.,École Doctorale Régional (EDR) en Infectiologie Tropicale d'Afrique Centrale, BP 876, Franceville, Gabon
| | - Sandrine E Nsango
- Faculté de Médecine et des Sciences Pharmaceutiques, Université de Douala, BP 2701, Douala, Cameroun
| | - Laura Aguilera
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), 08003 Barcelona, Spain
| | - Diego Ayala
- Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), BP 769, Franceville, Gabon.,Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Université Montpellier, CNRS, IRD, 64501 Montpellier, France
| | - Josefa González
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), 08003 Barcelona, Spain
| |
Collapse
|
17
|
Fofana A, Gendrin M, Romoli O, Yarbanga GAB, Ouédraogo GA, Yerbanga RS, Ouédraogo JB. Analyzing gut microbiota composition in individual Anopheles mosquitoes after experimental treatment. iScience 2021; 24:103416. [PMID: 34901787 PMCID: PMC8637483 DOI: 10.1016/j.isci.2021.103416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 08/27/2021] [Accepted: 11/05/2021] [Indexed: 01/04/2023] Open
Abstract
The microbiota of Anopheles mosquitoes influences malaria transmission. Antibiotics ingested during a blood meal impact the mosquito microbiome and malaria transmission, with substantial differences between drugs. Here, we assessed if amoxicillin affects the gut mosquito microbiota. We collected Anopheles larvae in Burkina Faso, kept them in semi-field conditions, and offered a blood meal to adult females. We tested the impact of blood supplementation with two alternative amoxicillin preparations on microbiota composition, determined by high-throughput sequencing in individual gut samples. Our analysis detected four major genera, Elizabethkingia, Wigglesworthia, Asaia, and Serratia. The antibiotic treatment significantly affected overall microbiota composition, with a specific decrease in the relative abundance of Elizabethkingia and Asaia during blood digestion. Besides its interest on the influence of amoxicillin on the mosquito microbiota, our study proposes a thorough approach to report negative-control data of high-throughput sequencing studies on samples with a reduced microbial load.
Collapse
Affiliation(s)
- Aminata Fofana
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso.,Université Nazi Boni, Bobo-Dioulasso 1091, Burkina Faso
| | - Mathilde Gendrin
- Microbiota of Insect Vectors Group, Institut Pasteur de la Guyane, 97306 Cayenne, French Guiana.,Institut Pasteur, Université de Paris, Department of Insect Vectors, 75015 Paris, France
| | - Ottavia Romoli
- Microbiota of Insect Vectors Group, Institut Pasteur de la Guyane, 97306 Cayenne, French Guiana
| | | | | | - Rakiswende Serge Yerbanga
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso.,Institut des Sciences et Techniques, 2779 Bobo Dioulasso, Burkina Faso
| | - Jean-Bosco Ouédraogo
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso.,Institut des Sciences et Techniques, 2779 Bobo Dioulasso, Burkina Faso
| |
Collapse
|
18
|
Mwagira-Maina S, Runo S, Wachira L, Kitur S, Nyasende S, Kemei B, Ochomo E, Matoke-Muhia D, Mbogo C, Kamau L. Genetic markers associated with insecticide resistance and resting behaviour in Anopheles gambiae mosquitoes in selected sites in Kenya. Malar J 2021; 20:461. [PMID: 34903240 PMCID: PMC8670025 DOI: 10.1186/s12936-021-03997-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 11/28/2021] [Indexed: 11/16/2022] Open
Abstract
Background Molecular diagnostic tools have been incorporated in insecticide resistance monitoring programmes to identify underlying genetic basis of resistance and develop early warning systems of vector control failure. Identifying genetic markers of insecticide resistance is crucial in enhancing the ability to mitigate potential effects of resistance. The knockdown resistance (kdr) mutation associated with resistance to DDT and pyrethroids, the acetylcholinesterase-1 (ace-1R) mutation associated with resistance to organophosphates and carbamates and 2La chromosomal inversion associated with indoor resting behaviour, were investigated in the present study. Methods Anopheles mosquitoes sampled from different sites in Kenya and collected within the context of malaria vector surveillance were analysed. Mosquitoes were collected indoors using light traps, pyrethrum spray and hand catches between August 2016 and November 2017. Mosquitoes were identified using morphological keys and Anopheles gambiae sensu lato (s.l.) mosquitoes further identified into sibling species by the polymerase chain reaction method following DNA extraction by alcohol precipitation. Anopheles gambiae and Anopheles arabiensis were analysed for the presence of the kdr and ace-1R mutations, while 2La inversion was only screened for in An. gambiae where it is polymorphic. Chi-square statistics were used to determine correlation between the 2La inversion karyotype and kdr-east mutation. Results The kdr-east mutation occurred at frequencies ranging from 0.5 to 65.6% between sites. The kdr-west mutation was only found in Migori at a total frequency of 5.3% (n = 124). No kdr mutants were detected in Tana River. The ace-1R mutation was absent in all populations. The 2La chromosomal inversion screened in An. gambiae occurred at frequencies of 87% (n = 30), 80% (n = 10) and 52% (n = 50) in Baringo, Tana River and Migori, respectively. A significant association between the 2La chromosomal inversion and the kdr-east mutation was found. Conclusion The significant association between the 2La inversion karyotype and kdr-east mutation suggests that pyrethroid resistant An. gambiae continue to rest indoors regardless of the presence of treated bed nets and residual sprays, a persistence further substantiated by studies documenting continued mosquito abundance indoors. Behavioural resistance by which Anopheles vectors prefer not to rest indoors may, therefore, not be a factor of concern in this study’s malaria vector populations.
Collapse
Affiliation(s)
- Sharon Mwagira-Maina
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
| | - Steven Runo
- Department of Biochemistry and Biotechnology, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya
| | - Lucy Wachira
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Stanley Kitur
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Sarah Nyasende
- Institute of Tropical Medicine and Infectious Diseases (ITROMID), P.O. Box 54840-00200, Nairobi, Kenya
| | - Brigid Kemei
- Centre for Global Health Research, KEMRI_CDC, P.O Box 1578-40100, Kisumu, Kenya
| | - Eric Ochomo
- Centre for Global Health Research, KEMRI_CDC, P.O Box 1578-40100, Kisumu, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Charles Mbogo
- KEMRI -Wellcome Trust Research Programme, Public Health Unit, P.O. Box 43640-00100, Nairobi, Kenya
| | - Luna Kamau
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| |
Collapse
|
19
|
Evolution of the Pyrethroids Target-Site Resistance Mechanisms in Senegal: Early Stage of the Vgsc-1014F and Vgsc-1014S Allelic Frequencies Shift. Genes (Basel) 2021; 12:genes12121948. [PMID: 34946897 PMCID: PMC8701854 DOI: 10.3390/genes12121948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/17/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
The evolution and spread of insecticide resistance mechanisms amongst malaria vectors across the sub-Saharan Africa threaten the effectiveness and sustainability of current insecticide-based vector control interventions. However, a successful insecticide resistance management plan relies strongly on evidence of historical and contemporary mechanisms circulating. This study aims to retrospectively determine the evolution and spread of pyrethroid resistance mechanisms among natural Anopheles gambiae s.l. populations in Senegal. Samples were randomly drawn from an existing mosquito sample, collected in 2013, 2017, and 2018 from 10 sentinel sites monitored by the Senegalese National Malaria Control Programme (NMCP). Molecular species of An. gambiae s.l. and the resistance mutations at the Voltage-gated Sodium Channel 1014 (Vgsc-1014) locus were characterised using PCR-based assays. The genetic diversity of the Vgsc gene was further analyzed by sequencing. The overall species composition revealed the predominance of Anopheles arabiensis (73.08%) followed by An. gambiae s.s. (14.48%), Anopheles coluzzii (10.94%) and Anopheles gambiae-coluzii hybrids (1.48%). Both Vgsc-1014F and Vgsc-1014S mutations were found in all studied populations with a spatial variation of allele frequencies from 3% to 90%; and 7% to 41%, respectively. The two mutations have been detected since 2013 across all the selected health districts, with Vgsc-L1014S frequency increasing over the years while Vgsc-1014F decreasing. At species level, the Vgsc-1014F and Vgsc-1014S alleles were more frequent amongst An. gambiae s.s. (70%) and An. arabiensis (20%). The Vgsc gene was found to be highly diversified with eight different haplotypes shared between Vgsc-1014F and Vgsc-1014S. The observed co-occurrence of Vgsc-1014F and Vgsc-1014S mutations suggest that pyrethroid resistance is becoming a widespread phenomenon amongst malaria vector populations, and the NMCP needs to address this issue to sustain the gain made in controlling malaria.
Collapse
|
20
|
Antonio-Nkondjio C, Doumbe-Belisse P, Djamouko-Djonkam L, Ngadjeu CS, Talipouo A, Kopya E, Bamou R, Mayi MPA, Sonhafouo-Chiana N, Nkahe DL, Tabue R, Fosah DA, Bigoga JD, Awono-Ambene P, Wondji CS. High efficacy of microbial larvicides for malaria vectors control in the city of Yaounde Cameroon following a cluster randomized trial. Sci Rep 2021; 11:17101. [PMID: 34429446 PMCID: PMC8385066 DOI: 10.1038/s41598-021-96362-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/03/2021] [Indexed: 11/12/2022] Open
Abstract
The rapid expansion of insecticide resistance and outdoor malaria transmission are affecting the efficacy of current malaria control measures. In urban settings, where malaria transmission is focal and breeding habitats are few, fixed and findable, the addition of anti-larval control measures could be efficient for malaria vector control. But field evidences for this approach remains scarce. Here we provide findings of a randomized-control larviciding trial conducted in the city of Yaoundé that support the efficacy of this approach. A two arms random control trial design including 26 clusters of 2 to 4 km2 each (13 clusters in the intervention area and 13 in the non-intervention area) was used to assess larviciding efficacy. The microbial larvicide VectoMax combining Bacillus thuringiensis var israelensis (Bti) and Bacillus sphaericus in a single granule was applied every 2 weeks in all standing water collection points. The anopheline density collected using CDC light traps was used as the primary outcome, secondary outcomes included the entomological inoculation rate, breeding habitats with anopheline larvae, and larval density. Baseline entomological data collection was conducted for 17 months from March 2017 to July 2018 and the intervention lasted 26 months from September 2018 to November 2020. The intervention was associated with a reduction of 68% of adult anopheline biting density and of 79% of the entomological inoculation rate (OR 0.21; 95% CI 0.14-0.30, P < 0.0001). A reduction of 68.27% was recorded for indoor biting anophelines and 57.74% for outdoor biting anophelines. No impact on the composition of anopheline species was recorded. A reduction of over 35% of adult Culex biting densities was recorded. The study indicated high efficacy of larviciding for reducing malaria transmission intensity in the city of Yaoundé. Larviciding could be part of an integrated control approach for controlling malaria vectors and other mosquito species in the urban environment.
Collapse
Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.
- Department of Vector Biology, Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
| | - P Doumbe-Belisse
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - L Djamouko-Djonkam
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - C S Ngadjeu
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - A Talipouo
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - E Kopya
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - R Bamou
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - M P Audrey Mayi
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - N Sonhafouo-Chiana
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | - D L Nkahe
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - R Tabue
- Ministry of Public Health, National Malaria Control Programme, Yaoundé, Cameroon
| | - D Achu Fosah
- Ministry of Public Health, National Malaria Control Programme, Yaoundé, Cameroon
| | - Jude D Bigoga
- Laboratory for Vector Biology and Control, National Reference Unit for Vector Control, The Biotechnology Center, Nkolbisson-University of Yaounde I, P.O. Box 3851, Messa, Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaoundé, Cameroon
| | - P Awono-Ambene
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
| | - Charles S Wondji
- Department of Vector Biology, Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
| |
Collapse
|
21
|
Larsen DA, Church RL. Pyrethroid Resistance in Anopheles gambiae Not Associated with Insecticide-Treated Mosquito Net Effectiveness Across Sub-Saharan Africa. Am J Trop Med Hyg 2021; 105:1097-1103. [PMID: 34424859 PMCID: PMC8592134 DOI: 10.4269/ajtmh.20-0229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/20/2021] [Indexed: 11/07/2022] Open
Abstract
Pyrethroid resistance is a major concern for malaria vector control programs that predominantly rely on insecticide-treated mosquito nets (ITNs). Contradictory results of the impact of resistance have been observed during field studies. We combined continent-wide estimates of pyrethroid resistance in Anopheles gambiae from 2006 to 2017, with continent-wide survey data to assess the effect of increasing pyrethroid resistance on the effectiveness of ITNs to prevent malaria infections in sub-Saharan Africa. We used a pooled-data approach and a meta-regression of survey regions to assess how pyrethroid resistance affects the association between ITN ownership and malaria outcomes for children 6 to 59 months of age. ITN ownership reduced the risk of malaria outcomes according to both the pooled and meta-regression approaches. According to the pooled analysis, there was no observed interaction between ITN ownership and estimated level of pyrethroid resistance (likelihood ratio [LR] test, 1.127 for malaria infection confirmed by the rapid diagnostic test, P = 0.2885; LR test = 0.161 for microscopy-confirmed malaria infection, P = 0.161; LR test = 0.646 for moderate or severe anemia, P = 0.4215). Using the meta-regression approach to determine the level of pyrethroid resistance did not explain any of the variance in subnational estimates of ITN effectiveness for any of the outcomes. ITNs decreased the risk of malaria independent of the levels of pyrethroid resistance in malaria vector populations.
Collapse
Affiliation(s)
- David A. Larsen
- Syracuse University Department of Public Health, Syracuse, New York
| | | |
Collapse
|
22
|
Kpanou CD, Sagbohan HW, Dagnon F, Padonou GG, Ossè R, Salako AS, Sidick A, Sewadé W, Sominahouin A, Condo P, Ahmed SH, Impoinvil D, Akogbéto M. Characterization of resistance profile (intensity and mechanisms) of Anopheles gambiae in three communes of northern Benin, West Africa. Malar J 2021; 20:328. [PMID: 34315480 PMCID: PMC8314583 DOI: 10.1186/s12936-021-03856-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/16/2021] [Indexed: 11/30/2022] Open
Abstract
Background The selection and the spread of insecticide resistance in malaria vectors to the main classes of insecticides used in vector control tools are a major and ongoing challenge to malaria vector control programmes. This study aimed to determine the intensity of vector resistance to insecticides in three regions of Benin with different agro-ecological characteristics. Methods Larvae of Anopheles gambiae sensu lato (s.l.) were collected from September to November 2017 in different larval sites in three northern Benin communes: Parakou, Kandi and Malanville. Two to five-day-old, non-blood-fed, female mosquitoes were exposed to papers impregnated with deltamethrin, permethrin and bendiocarb at dosages of 1 × the diagnostic dose, 5 × and 10 × to determine the intensity of resistance in these vectors. Molecular frequencies of the kdr L1014F and ace-1R G119S insecticide resistance mutations and levels of detoxification enzymes were determined for mosquitoes sampled at each study site. Results Resistance to pyrethroids (permethrin and deltamethrin) was recorded in all three communes with mortality rates below 60% using the diagnostic dose (1x). The results obtained after exposure of An. gambiae to permethrin 10 × were 99% in Kandi, 98% in Malanville and 99% in Parakou. With deltamethrin 10x, mortality rates were 100% in Kandi, 96% in Malanville and 73% in Parakou. For the diagnostic dose of bendiocarb, suspected resistance was recorded in the communes of Malanville (97%) and Kandi (94%) while sensitivity was observed in Parakou (98%).Using the 10 × dose, mortality was 98% in Kandi, 100% in Malanville and 99% in Parakou. The frequencies of the kdr L1014F allele varied between 59 and 83% depending on the sites and species of the An. gambiae complex, while the frequency of the ace-1R G119S gene varied between 0 and 5%. Biochemical tests showed high levels of oxidase and esterase activity compared to the susceptible colony strain of An. gambiae sensu stricto (Kisumu strain). Conclusion Anopheles gambiae showed a generalized loss of susceptibility to permethrin and deltamethrin but also showed moderate to high intensity of resistance in different regions of Benin. This high intensity of resistance is a potential threat to the effectiveness of vector control.
Collapse
Affiliation(s)
- Casimir Dossou Kpanou
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin.
| | - Hermann W Sagbohan
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Fortuné Dagnon
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Bénin.,Bill & Melinda Gates Foundation, Lagos, Nigeria
| | - Germain G Padonou
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Razaki Ossè
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Université Nationale d'Agriculture de Porto-Novo, Porto-Novo, Bénin
| | - Albert Sourou Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Aboubakar Sidick
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Wilfried Sewadé
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin
| | - André Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| | - Patrick Condo
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Bénin
| | - Saadani Hassani Ahmed
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Bénin
| | - Daniel Impoinvil
- US President's Malaria Initiative, Centers for Disease Control and Prevention for Disease Control (CDC), Georgia, USA
| | - Martin Akogbéto
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Bénin
| |
Collapse
|
23
|
Zhao N, Sesay I, Tu H, Yamba F, Lu L, Guo Y, Song X, Wang J, Liu X, Yue Y, Wu H, Liu Q. Entomological and Molecular Surveillance of Anopheles Mosquitoes in Freetown, Sierra Leone, 2019. Front Public Health 2021; 9:649672. [PMID: 34222167 PMCID: PMC8247763 DOI: 10.3389/fpubh.2021.649672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/26/2021] [Indexed: 11/23/2022] Open
Abstract
Background: Malaria is endemic in Sierra Leone, with stable and perennial transmission in all parts of the country. At present, the main prevention and control measures for mosquito vectors here involve insecticide treated nets (ITN) and indoor residual spraying (IRS). The most recent entomological surveillance was conducted prior to the civil war, between 1990 and 1994. Therefore, a new entomological surveillance required to support targeted malaria control strategies. Methods:Anopheles mosquitoes were collected between June and December 2019 using the light trap method. On these, we conducted species identification, analyzed seasonal fluctuation and Plasmodium infection rate, and monitored insecticide resistance. Results: Surveillance of seasonal fluctuation showed that there were two peak of Anopheles density in July (mean 13.67 mosquitoes/trap/night) and October (mean 13.00 mosquitoes/trap/night). Meanwhile, the lowest Anopheles density was seen in early September. Ninety-one representatives of Anopheles gambiae s.l. were selected and identified as An. coluzzii (n = 35) and An. gambiae s.s. (n = 56) using PCR. An. coluzzii and An. gambiae s.s. were found to be heterozygous resistant to the knockdown resistance (kdr) L1014F mutation (100%). Meanwhile, the East African mutation (kdr L1014S) was absent in the tested mosquitoes. Three mosquitoes that tested positive for the parasite, had an individual Plasmodium falciparum infection rate of 12.50, 16.67, and 14.29%. The sampling dates of positive mosquitoes were distributed in the two periods of peak Anopheles mosquito density. Conclusion: This study identified the dominant Anopheles species in Freetown as An. gambiae while the predominant species within the An. gambiae complex was An. gambiae sensu stricto. Surveillance of seasonal fluctuations and high P. falciparum infection rates in Anopheles indicate that the alternation of drought and rainy seasons from June to July, and from October to November, are the key periods for malaria control and prevention in Freetown, Sierra Leone. The high frequency of kdr allele mutations in An. gambiae calls for close monitoring of vector susceptibility to insecticides and tracing of resistance mechanisms in order to develop more effective vector control measures and strategies.
Collapse
Affiliation(s)
- Ning Zhao
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.,Sierra Leone-China Friendship Biosafety Laboratory, Freetown, Sierra Leone
| | - Ishaq Sesay
- Sierra Leone-China Friendship Biosafety Laboratory, Freetown, Sierra Leone
| | - Hong Tu
- Sierra Leone-China Friendship Biosafety Laboratory, Freetown, Sierra Leone.,Chinese Center for Disease Control and Prevention, National Institute of Parasitic Diseases, Shanghai, China
| | - Frederick Yamba
- Ministry of Health and Sanitation of Sierra Leone, Freetown, Sierra Leone
| | - Liang Lu
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.,Sierra Leone-China Friendship Biosafety Laboratory, Freetown, Sierra Leone
| | - Yuhong Guo
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Xiuping Song
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Jun Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Xiaobo Liu
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yujuan Yue
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Haixia Wu
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Qiyong Liu
- State Key Laboratory of Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| |
Collapse
|
24
|
Anosike CA, Babandi A, Ezeanyika LUS. Potentiation Effects of Ficus sycomorus Active Fraction Against Permethrin-Resistant Field-Population of Anopheles coluzzii (Diptera: Culicidae). NEOTROPICAL ENTOMOLOGY 2021; 50:484-496. [PMID: 33661503 DOI: 10.1007/s13744-021-00858-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Insecticide resistance in mosquitoes is increasing amidst growing cases of global malaria, leading to high fatality in mostly Africa. To overcome the resistance as well as environmental effects of the synthetic insecticides, preliminary insecticidal and botanical potentiating effects of sub-lethal concentration (LC25) Ficus sycomorus active fraction (AFFS) and its synergistic potential with standard insecticide permethrin were evaluated against malarial vector Anopheles coluzzii (Coetzee & Wilkerson) populations. The glutathione-S-transferase (GST) inhibitory activity of the AFFS was also investigated compared to standard GST inhibitor, diethyl meleate (DEM). The WHO standard protocol for adult bioassay was used to expose the adult mosquitoes with sub-lethal concentration (LD25=0.49 mg/ml) of the plants' active fraction and permethrin (0.75%). The permethrin susceptibility screening result showed high level of resistance to permethrin in the field populations of A. coluzzii from Kano with 50.29 ± 2.14% average mortality after exposure to WHO diagnostic dose 0.75% permethrin. Post hoc Fisher's exact test showed that combination of sub-lethal concentration of AFFS with permethrin (mortality=73.02±12.10%; p=0.00352; RR=0.6923 and 95% CI = 0.5358-0.8946) was statistically significant, while the combination of sub-lethal concentration of AFFS with DEM showed no statistical difference (mortality=63.22±5.03; p=1; RR=0.6667 and 95% CI=0.4470-0.8438). This potentiation effect was signified to be additive effects with co-toxicity factor (CTF) of - 12.66. There was significant reduction of GST activities in the AFFS- and permethrin -exposed groups compared to unexposed populations of A. coluzzii (p < 0.05). The AFFS additively potentiate the permethrin activities by inhibiting GSTs, bio-transformational enzymes implicated in pyrethroids resistance. This study finding generally signifies the potential for bio-rational insecticide approach for malarial vector control.
Collapse
Affiliation(s)
| | - Abba Babandi
- Dept of Biochemistry, Univ of Nigeria, Nsukka, Enugu, Nigeria.
- Dept of Biochemistry, Bayero Univ, Kano, Nigeria.
| | | |
Collapse
|
25
|
Keïta M, Sogoba N, Kané F, Traoré B, Zeukeng F, Coulibaly B, Sodio AB, Traoré SF, Djouaka R, Doumbia S. Multiple Resistance Mechanisms to Pyrethroids Insecticides in Anopheles gambiae sensu lato Population From Mali, West Africa. J Infect Dis 2021; 223:S81-S90. [PMID: 33906223 PMCID: PMC8079131 DOI: 10.1093/infdis/jiaa190] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background Insecticide-based vector control is responsible for reducing malaria mortality and morbidity. Its success depends on a better knowledge of the vector, its distribution, and resistance status to the insecticides used. In this paper, we assessed Anopheles gambiae sensu lato (A gambiae s.l.) population resistance to pyrethroids in different ecological settings. Methods The World Health Organization standard bioassay test was used to assess F0A gambiae s.l. susceptibility to pyrethroids. Biochemical Synergist assays were conducted with piperonyl butoxide (PBO), S,S,S-tributyl phosphotritioate, and diethyl maleate. L1014F, L1014S, and N1575Y knockdown resistance (kdr) mutations were investigated using TaqMan genotyping. Results Anopheles gambiae sensu lato was composed of Anopheles arabienisis, Anopheles coluzzii, and A gambiae in all study sites. Anopheles gambiae sensu lato showed a strong phenotypic resistance to deltamethrin and permethrin in all sites (13% to 41% mortality). In many sites, pre-exposure to synergists partially improved the mortality rate suggesting the presence of detoxifying enzymes. The 3 kdr (L1014F, L1014S, and N1575Y) mutations were found, with a predominance of L1014F, in all species. Conclusions Multiple resistance mechanisms to pyrethroids were observed in A gambiae s.l. in Mali. The PBO provided a better partial restoration of susceptibility to pyrethroids, suggesting that the efficacy of long-lasting insecticidal nets may be improved with PBO.
Collapse
Affiliation(s)
- Moussa Keïta
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Nafomon Sogoba
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Fousseyni Kané
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Boissé Traoré
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Francis Zeukeng
- The AgroEcohealth Platform, International Institute of Tropical Agriculture (IITA-Benin), Cotonou, Benin
| | - Boubacar Coulibaly
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Ambiélè Bernard Sodio
- Faculty of Science and Technique, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Sekou Fantamady Traoré
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Rousseau Djouaka
- The AgroEcohealth Platform, International Institute of Tropical Agriculture (IITA-Benin), Cotonou, Benin
| | - Seydou Doumbia
- Malaria Research and Training Center, International Center for Excellence in Research, Faculty of Medicine and Odonto Stomatology, University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| |
Collapse
|
26
|
Munywoki DN, Kokwaro ED, Mwangangi JM, Muturi EJ, Mbogo CM. Insecticide resistance status in Anopheles gambiae (s.l.) in coastal Kenya. Parasit Vectors 2021; 14:207. [PMID: 33879244 PMCID: PMC8056612 DOI: 10.1186/s13071-021-04706-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/31/2021] [Indexed: 11/12/2022] Open
Abstract
Background The rapid and widespread evolution of insecticide resistance has emerged as one of the major challenges facing malaria control programs in sub-Saharan Africa. Understanding the insecticide resistance status of mosquito populations and the underlying mechanisms of insecticide resistance can inform the development of effective and site-specific strategies for resistance prevention and management. The aim of this study was to investigate the insecticide resistance status of Anopheles gambiae (s.l.) mosquitoes from coastal Kenya. Methods Anopheles gambiae (s.l.) larvae sampled from eight study sites were reared to adulthood in the insectary, and 3- to 5-day-old non-blood-fed females were tested for susceptibility to permethrin, deltamethrin, dichlorodiphenyltrichloroethane (DDT), fenitrothion and bendiocarb using the standard World Health Organization protocol. PCR amplification of rDNA intergenic spacers was used to identify sibling species of the An. gambiae complex. The An. gambiae (s.l.) females were further genotyped for the presence of the L1014S and L1014F knockdown resistance (kdr) mutations by real-time PCR. Results Anopheles arabiensis was the dominant species, accounting for 95.2% of the total collection, followed by An. gambiae (s.s.), accounting for 4.8%. Anopheles gambiae (s.l.) mosquitoes were resistant to deltamethrin, permethrin and fenitrothion but not to bendiocarb and DDT. The L1014S kdr point mutation was detected only in An. gambiae (s.s.), at a low allelic frequency of 3.33%, and the 1014F kdr mutation was not detected in either An. gambiae (s.s.) or An. arabiensis. Conclusion The findings of this study demonstrate phenotypic resistance to pyrethroids and organophosphates and a low level of the L1014S kdr point mutation that may partly be responsible for resistance to pyrethroids. This knowledge may inform the development of insecticide resistance management strategies along the Kenyan Coast. ![]()
Collapse
Affiliation(s)
- Daniel N Munywoki
- Center for Geographic Medicine Research, Coast, Kenya Medical Research Institute, P.O Box 230-80108, Kilifi, Kenya. .,Department of Zoological Sciences, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
| | - Elizabeth D Kokwaro
- Department of Zoological Sciences, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya
| | - Joseph M Mwangangi
- Center for Geographic Medicine Research, Coast, Kenya Medical Research Institute, P.O Box 230-80108, Kilifi, Kenya
| | - Ephantus J Muturi
- Crop Bioprotection Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, 1815 N. University, St. Peoria, IL, 61604, USA
| | - Charles M Mbogo
- Center for Geographic Medicine Research, Coast, Kenya Medical Research Institute, P.O Box 230-80108, Kilifi, Kenya.,Population Health Unit, KEMRI-Wellcome Trust Research Programme, Lenana Road, 197 Lenana Place, P.O Box 43640-00100, Nairobi, Kenya
| |
Collapse
|
27
|
Sagbohan HW, Kpanou CD, Osse R, Dagnon F, Padonou GG, Sominahouin AA, Salako AS, Sidick A, Sewade W, Akinro B, Ahmed S, Impoinvil D, Agbangla C, Akogbeto M. Intensity and mechanisms of deltamethrin and permethrin resistance in Anopheles gambiae s.l. populations in southern Benin. Parasit Vectors 2021; 14:202. [PMID: 33853655 PMCID: PMC8048290 DOI: 10.1186/s13071-021-04699-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/22/2021] [Indexed: 11/24/2022] Open
Abstract
Background Insecticide resistance is threatening the effectiveness of efforts to control malaria vectors in Benin. This study explores the levels and mechanisms of insecticide resistance in An. gambiae s.l. to pyrethroids. Methods Larvae were collected from August 2017 to July 2018 in five communes in southern Benin (Adjohoun, Allada, Bohicon, Cotonou, and Porto-Novo) representing diverse ecological regions, and were reared in Benin’s insectary. Two- to five-day-old female mosquitoes from each district were exposed to multiple doses of deltamethrin and permethrin (1×, 2×, 5×, and 10×) using the WHO insecticide resistance intensity bioassay. The effect of pre-exposure to the synergist, piperonyl butoxide (PBO), was also tested at different pyrethroid doses. Molecular allele frequencies of kdr (1014F) and ace-1R (119S) insecticide resistance mutations and levels of detoxification enzymes were determined for mosquitoes sampled from each study area. Results An. gambiae s.l. were resistant to pyrethroid-only exposure up to 10× the diagnostic doses in all the study sites for both deltamethrin and permethrin. Mortality was significantly higher in An. gambiae s.l. pre-exposed to PBO followed by exposure to deltamethrin or permethrin compared to mosquitoes exposed to deltamethrin or permethrin only (p < 0.001). The difference in mortality between deltamethrin only and PBO plus deltamethrin was the smallest in Cotonou (16–64%) and the greatest in Bohicon (12–93%). The mortality difference between permethrin only and PBO plus permethrin was the smallest in Cotonou (44–75%) and the greatest in Bohicon (22–72%). In all the study sites, the kdr resistance allele (1014F) frequency was high (75–100%), while the ace-1 resistance allele (G119S) frequency was low (0–3%). Analysis of the metabolic enzymatic activity of An. gambiae s.l. showed overexpression of nonspecific esterases and glutathione S-transferases (GST) in all study sites. In contrast to the PBO results, oxidase expression was low and was similar to the susceptible An. gambiae s.s. Kisumu strain in all sites. Conclusion There is high-intensity resistance to pyrethroids in southern Benin. However, pre-exposure to PBO significantly increased susceptibility to the pyrethroids in the different An. gambiae s.l. populations sampled. The use of PBO insecticide-treated bed nets may help maintain the gains in An. gambiae (s.l.) control in southern Benin. Graphical Abstract ![]()
Collapse
Affiliation(s)
- Hermann Watson Sagbohan
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin. .,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin.
| | - Casimir D Kpanou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | - Razaki Osse
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,National University of Agriculture of Porto-Novo, Porto-Novo, Benin
| | | | - Germain G Padonou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | | | - Albert Sourou Salako
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.,Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin
| | | | - Wilfried Sewade
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | - Saadani Ahmed
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | - Daniel Impoinvil
- US President's Malaria Initiative, Centers for Disease Control and Prevention (CDC), Atlanta, USA
| | - Clément Agbangla
- Faculty of Science and Technology of the University of Abomey-Calavi, Godomey, Benin.,Genetics and Biotechnology Laboratory of the UAC, Godomey, Benin
| | - Martin Akogbeto
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| |
Collapse
|
28
|
Gueye OK, Tchouakui M, Dia AK, Faye MB, Ahmed AA, Wondji MJ, Nguiffo DN, J. Mugenzi LM, Tripet F, Konaté L, Diabate A, Dia I, Gaye O, Faye O, Niang EHA, S. Wondji C. Insecticide Resistance Profiling of Anopheles coluzzii and Anopheles gambiae Populations in the Southern Senegal: Role of Target Sites and Metabolic Resistance Mechanisms. Genes (Basel) 2020; 11:E1403. [PMID: 33255805 PMCID: PMC7760107 DOI: 10.3390/genes11121403] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/05/2020] [Accepted: 11/20/2020] [Indexed: 12/22/2022] Open
Abstract
The emergence and spread of insecticide resistance among the main malaria vectors is threatening the effectiveness of vector control interventions in Senegal. The main drivers of this resistance in the Anopheles gambiae complex (e.g., An. gambiae and Anopheles coluzzii) remains poorly characterized in Senegal. Here we characterized the main target site and metabolic resistances mechanisms among the An. gambiae and An. coluzzii populations from their sympatric and allopatric or predominance area in Senegal. Larvae and pupae of An. gambiae s.l. were collected, reared to adulthood, and then used for insecticides susceptibility and synergist assays using the WHO (World Health Organisation) test kits for adult mosquitoes. The TaqMan method was used for the molecular characterization of the main target site insecticide resistance mechanisms (Vgsc-1014F, Vgsc-1014S, N1575Y and G119S). A RT-qPCR (Reverse Transcriptase-quantitative Polymerase Chaine Reaction) was performed to estimate the level of genes expression belonging to the CYP450 (Cytochrome P450) family. Plasmodium infection rate was investigated using TaqMan method. High levels of resistance to pyrethroids and DDT and full susceptibility to organophosphates and carbamates where observed in all three sites, excepted a probable resistance to bendiocarb in Kedougou. The L1014F, L1014S, and N1575Y mutations were found in both species. Pre-exposure to the PBO (Piperonyl butoxide) synergist induced a partial recovery of susceptibility to permethrin and full recovery to deltamethrin. Subsequent analysis of the level of genes expression, revealed that the CYP6Z1 and CYP6Z2 genes were over-expressed in wild-resistant mosquitoes compared to the reference susceptible strain (Kisumu), suggesting that both the metabolic resistance and target site mutation involving kdr mutations are likely implicated in this pyrethroid resistance. The presence of both target-site and metabolic resistance mechanisms in highly pyrethroid-resistant populations of An. gambiae s.l. from Senegal threatens the effectiveness and the sustainability of the pyrethroid-based tools and interventions currently deployed in the country. The Kdr-west mutation is widely widespread in An. coluzzii sympatric population. PBO or Duo nets and IRS (Indoor Residual Spraying) with organophosphates could be used as an alternative measure to sustain malaria control in the study area.
Collapse
Affiliation(s)
- Oumou. K. Gueye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Magellan Tchouakui
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Abdoulaye K. Dia
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Mouhamed B. Faye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Amblat A. Ahmed
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Murielle J. Wondji
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Daniel N. Nguiffo
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Leon. M. J. Mugenzi
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
| | - Frederic Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Newcastle-under-Lyme ST5 5BG, UK;
| | - Lassana Konaté
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Abdoulaye Diabate
- Centre Muraz/Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso BP 545, Burkina Faso;
| | - Ibrahima Dia
- Pôle de Zoologie Médicale, Institut Pasteur de Dakar, 36 Avenue Pasteur, Dakar BP 220, Senegal;
| | - Oumar Gaye
- Service de Parasitologie-Mycologie, Faculté de Médecine, Pharmacie et d’Odontologie, Université Cheikh Anta Diop, Dakar BP 5005, Senegal;
| | - Ousmane Faye
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - El Hadji A. Niang
- Laboratoire d’Écologie Vectorielle et Parasitaire, Faculté des Sciences et Techniques Université Cheikh Anta Diop, Dakar BP 5005, Senegal; (A.K.D.); (M.B.F.); (A.A.A.); (L.K.); (O.F.); (E.H.A.N.)
| | - Charles S. Wondji
- Centre for Research in Infectious Diseases (CRID), Yaounde BP 13591, Cameroon; (M.T.); (M.J.W.); (D.N.N.); (L.M.J.M.)
- Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| |
Collapse
|
29
|
Debalke S, Habtewold T, Christophides GK, Duchateau L. Stability of the effect of silencing fibronectin type III domain-protein 1 (FN3D1) gene on Anopheles arabiensis reared under different breeding site conditions. Parasit Vectors 2020; 13:202. [PMID: 32307003 PMCID: PMC7168852 DOI: 10.1186/s13071-020-04078-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/10/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Malaria vector mosquitoes acquire midgut microbiota primarily from their habitat. The homeostasis of these microbial communities plays an essential role in the mosquito longevity, the most essential factor in the mosquito vectorial capacity. Our recent study revealed that silencing genes involved in regulation of the midgut homeostasis including FN3D1, FN3D3 and GPRGr9 reduced the survival of female adult Anopheles arabiensis mosquitoes. In the present study, we investigate the stability of the gene silencing efficiency of mosquitoes reared in three different breeding conditions representing distinct larval habitat types: town brick pits in Jimma, flood pools in the rural land of Asendabo and roadside pools in Wolkite. METHODS First-instar larvae of An. arabiensis mosquitoes were reared separately using water collected from the three breeding sites. The resulting adult females were micro-injected with dsRNA targeting the FN3D1 gene (AARA003032) and their survival was monitored. Control mosquitoes were injected with dsRNA Lacz. In addition, the load of midgut microbiota of these mosquitoes was determined using flow cytometry. RESULTS Survival of naïve adult female mosquitoes differed between the three sites. Mosquitoes reared using water collected from brick pits and flood pools survived longer than mosquitoes reared using water collected from roadside. However, the FN3D1 gene silencing effect on survival did not differ between the three sites. CONCLUSIONS The present study revealed that the efficacy of FN3D1 gene silencing is not affected by variation in the larval habitat. Thus, silencing this gene has potential for application throughout sub-Saharan Africa.
Collapse
Affiliation(s)
- Serkadis Debalke
- Department of Medical Laboratory Science & Pathology, Jimma University, Jimma, Ethiopia
- Biometrics Research Group, Ghent University, Ghent, Belgium
| | - Tibebu Habtewold
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Luc Duchateau
- Biometrics Research Group, Ghent University, Ghent, Belgium
| |
Collapse
|
30
|
Talom AD, Essoung MA, Gbankoto A, Tchigossou G, Akoton R, Sahabi BBA, Atoyebi SM, Fotso Kuate A, Verspoor RL, Tamò M, Tchuinkam T, Lehman GL, Lines J, Wondji CS, Djouaka R. A preliminary analysis on the effect of copper on Anopheles coluzzii insecticide resistance in vegetable farms in Benin. Sci Rep 2020; 10:6392. [PMID: 32286370 PMCID: PMC7156479 DOI: 10.1038/s41598-020-63086-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 03/17/2020] [Indexed: 12/02/2022] Open
Abstract
The use of agrochemicals in vegetable production could influence the selection for insecticide resistance in malaria vectors. Unfortunately, there is a dearth of information on the potential contribution of agrochemicals to insecticide resistance in Anopheles mosquitoes breeding on vegetable farms in southern Benin. A Knowledge, Attitudes and Practices study was conducted with 75 vegetable farmers from Houeyiho and Seme to determine the main agrochemicals used in vegetable production, and the concentration and frequency of application, among other details. Mosquitoes and breeding water were sampled from the farms for analysis. Bioassays were conducted on mosquitoes, while breeding water was screened for heavy metal and pesticide residue contamination. Lambda-cyhalothrin was the main insecticide (97.5%) used by farmers, and Anopheles coluzzii was the main mosquito identified. This mosquito species was resistant (30-63% mortality rate) to λ-cyhalothrin. It was also observed that 16.7% of the examined breeding sites were contaminated with λ-cyhalothrin residues. Furthermore, copper contamination detected in mosquito breeding sites showed a positive correlation (r = 0.81; P = 0.0017) with mosquito resistance to λ-cyhalothrin. The presence of copper in λ-cyhalothrin-free breeding sites, where mosquitoes have developed resistance to λ-cyhalothrin, suggests the involvement of copper in the insecticide resistance of malaria vectors; this, however, needs further investigation.
Collapse
Affiliation(s)
- Armand Defo Talom
- University of Dschang, Vector Borne Diseases Laboratory (VBID), Po Box 067, Dschang, Cameroon.
- International Institute of Tropical Agriculture, Yaoundé, Cameroon.
| | - Michele Agnes Essoung
- University of Dschang, Vector Borne Diseases Laboratory (VBID), Po Box 067, Dschang, Cameroon
- International Institute of Tropical Agriculture, Yaoundé, Cameroon
| | - Adam Gbankoto
- University of Abomey Calavi, Laboratory of Experimental Physiology and Pharmacology, Faculty of Sciences and Technology BP 526, Cotonou, Benin
| | - Genevieve Tchigossou
- University of Abomey Calavi, Laboratory of Experimental Physiology and Pharmacology, Faculty of Sciences and Technology BP 526, Cotonou, Benin
- International Institute of Tropical Agriculture, Cotonou, 08 BP, 0932, Benin
| | - Romaric Akoton
- University of Abomey Calavi, Laboratory of Experimental Physiology and Pharmacology, Faculty of Sciences and Technology BP 526, Cotonou, Benin
- International Institute of Tropical Agriculture, Cotonou, 08 BP, 0932, Benin
| | | | - Seun Michael Atoyebi
- International Institute of Tropical Agriculture, Cotonou, 08 BP, 0932, Benin
- Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, P.O. Box 5116, Oyo State, Nigeria
| | | | - Rudi L Verspoor
- University of Liverpool, Institute of Integrative Biology, Liverpool, L697ZB, United Kingdom
| | - Manuele Tamò
- International Institute of Tropical Agriculture, Cotonou, 08 BP, 0932, Benin
| | - Timoleon Tchuinkam
- University of Dschang, Vector Borne Diseases Laboratory (VBID), Po Box 067, Dschang, Cameroon
| | | | - Jo Lines
- London School of Hygiene & Tropical Medicine, London, UK
| | - Charles S Wondji
- International Institute of Tropical Agriculture, Yaoundé, Cameroon
- Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Rousseau Djouaka
- International Institute of Tropical Agriculture, Cotonou, 08 BP, 0932, Benin.
| |
Collapse
|
31
|
Djamouko-Djonkam L, Nkahe DL, Kopya E, Talipouo A, Ngadjeu CS, Doumbe-Belisse P, Bamou R, Awono-Ambene P, Tchuinkam T, Wondji CS, Antonio-Nkondjio C. Implication of Anopheles funestus in malaria transmission in the city of Yaoundé, Cameroon. ACTA ACUST UNITED AC 2020; 27:10. [PMID: 32048986 PMCID: PMC7015064 DOI: 10.1051/parasite/2020005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/26/2020] [Indexed: 01/24/2023]
Abstract
The contribution of Anopheles funestus to malaria transmission in the urban environment is still not well documented. The present study assesses the implication of An. funestus in malaria transmission in two districts, Nsam and Mendong, in the city of Yaoundé. Adult mosquitoes were collected using Centers for Disease Control and Prevention miniature light traps (CDC-LT) and human landing catches from April 2017 to March 2018 and were identified morphologically to the species level. Those belonging to the Anopheles gambiae complex and to the Anopheles funestus group were further processed by PCR to identify members of each complex/group. Anopheline mosquitoes were analysed to determine their infection status using an enzyme-linked immunosorbent assay. Bioassays were conducted with 2–5-day-old female Anopheles funestus and An. gambiae s.l. to determine their susceptibility to permethrin, deltamethrin and dichlorodiphenyltrichloroethane (DDT). Six anopheline species were collected in the peri-urban district of Mendong: Anopheles gambiae, An. coluzzii, An. funestus, An. leesoni, An. ziemanni and An. marshallii; only four out of the six were recorded in Nsam. Of the two members of the Anopheles gambiae complex collected, An. coluzzii was the most prevalent. Anopheles coluzzii was the most abundant species in Nsam, while An. funestus was the most abundant in Mendong. Both Anopheles funestus and An. gambiae s.l. were found to be infected with human Plasmodium at both sites, and both were found to be resistant to DDT, permethrin, and deltamethrin. This study confirms the participation of An. funestus in malaria transmission in Yaoundé and highlights the need to also target this species for sustainable control of malaria transmission.
Collapse
Affiliation(s)
- Landre Djamouko-Djonkam
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Diane Leslie Nkahe
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Edmond Kopya
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Abdou Talipouo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Carmene Sandra Ngadjeu
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Patricia Doumbe-Belisse
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Roland Bamou
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Timoléon Tchuinkam
- Vector Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Sciences of the University of Dschang, P.O. Box 067, Dschang, Cameroon
| | | | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination Pour la Lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon - Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA Liverpool, UK
| |
Collapse
|
32
|
Ngadjeu CS, Doumbe-Belisse P, Talipouo A, Djamouko-Djonkam L, Awono-Ambene P, Kekeunou S, Toussile W, Wondji CS, Antonio-Nkondjio C. Influence of house characteristics on mosquito distribution and malaria transmission in the city of Yaoundé, Cameroon. Malar J 2020; 19:53. [PMID: 32000786 PMCID: PMC6993434 DOI: 10.1186/s12936-020-3133-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/22/2020] [Indexed: 12/31/2022] Open
Abstract
Background Improving house structure is known to limit contact between humans and mosquitoes and reduce malaria transmission risk. In the present study, the influence of house characteristics on mosquito distribution and malaria transmission risk was assessed in the city of Yaoundé. Methods The study was conducted from March 2017 to June 2018 in 32 districts of the city of Yaoundé. Mosquito collections were performed indoor in 10 to 15 houses per district using CDC light traps. A total of 467 houses, selected randomly were used. A pretested questionnaire was submitted to participants of the study to collect information on the household: the number of people per house, education level, type of walls, presence of ceilings and eaves, number of windows, usage of long-lasting insecticidal nets (LLINs), number of bedroom and number of window. Mosquitoes collected were identified morphologically. Anophelines were tested by ELISA to detect infection by Plasmodium parasites. General Estimating Equations adjusting for repeated measures in the same house fitting negative binomial analysis were used to assess the influence of house characteristics on mosquito distribution. Results A total of 168,039 mosquitoes were collected; Culex spp emerged as the predominant species (96.48%), followed by Anopheles gambiae sensu lato (s.l.) (2.49%). Out of the 1033 An. gambiae s.l. identified by PCR, 90.03% were Anopheles coluzzii and the remaining were An. gambiae sensu stricto (s.s.) (9.97%). The high number of people per household, the presence of screens on window and the possession of LLINs were all associated with fewer mosquitoes collected indoors, whilst opened eaves, the high number of windows, the presence of holes in walls and living close to breeding sites were associated with high densities of mosquitoes indoor. Out of 3557 Anophelines tested using ELISA CSP, 80 were found infected by Plasmodium falciparum parasites. The proportion of mosquitoes infected did not vary significantly according to house characteristics. Conclusion The study indicated that several house characteristics such as, the presence of holes on walls, opened eaves, unscreened window and living close to breeding sites, favored mosquito presence in houses. Promoting frequent use of LLINs and house improvement measures, such as the use of screen on windows, closing eaves, cleaning the nearby environment, should be integrated in strategies to improve malaria control in the city of Yaoundé.
Collapse
Affiliation(s)
- Carmene S Ngadjeu
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Patricia Doumbe-Belisse
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Abdou Talipouo
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Landre Djamouko-Djonkam
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Sciences, University of Dschang, P.O. Box 337, Dschang, Cameroon
| | - Parfait Awono-Ambene
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Sevilor Kekeunou
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Wilson Toussile
- Ecole Nationale Supérieure Polytechnique University of Yaoundé I, P.O. Box 8390, Yaounde, Cameroon.,Faculty of Medicine Paris-Sud, 63 rue Gabriel Peri, 94276, Le Kremlin-Bicêtre, Paris, France
| | - Charles S Wondji
- Vector Biology Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK
| | - Christophe Antonio-Nkondjio
- Institut de Recherche de Yaoundé (IRY), Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon. .,Vector Biology Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
33
|
Pesticides and the evolution of the genetic structure of Anopheles coluzzii populations in some localities in Benin (West Africa). Malar J 2019; 18:407. [PMID: 31805939 PMCID: PMC6896764 DOI: 10.1186/s12936-019-3036-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 11/26/2019] [Indexed: 01/25/2023] Open
Abstract
Background Changes in the natural habitats of insect groups are determined the genetic polymorphisms between individuals. The objective of this study was to establish the genetic structure of the Anopheles coluzzii populations in four localities of Benin. Methods Insecticide surveys and larval sampling were conducted on 4 study localities, including Cotonou, Ketou, Zagnanado, and Sô-Ava. Molecular characterizations were performed on the Anopheles mosquitoes collected with the allelic and genotypic frequencies of kdr gene determined. The multiple comparison Chi square test for proportions was performed with R version 3.3.3. Next, the observed heterozygosity, expected heterozygosity, and indices of fixation, and genetic differentiation were estimated. Finally, the Hardy–Weinberg equilibrium (EHW) was determined to assess whether panmixia exists in the different populations of mosquitoes of the agroecological zones under study. Results Carbamates, pyrethroids, organophosphorus and organochlorines use have been reported in all localities except Sô-Ava. Anopheles coluzzii was strongly represented across all study localities. The L1014F allele was observed in the localities of Kétou, Cotonou and Zagnanado. Likewise, insecticide selection pressure of homozygous resistant individuals (L1014F/L1014F) was significantly higher in Kétou, Cotonou and Zagnanado (p value < 0.05). Surprisingly in Sô-Ava, a relatively high frequency of the L1014F allele despite the reported absence of pesticide use was observed. All mosquito populations were found to be deficient in heterozygosity across the study sites (FIS< 0). No genetic differentiation (FST< 0) was observed in the localities of Zagnanado and Kétou. Conclusion The survey on the use of insecticides showed that insecticide selection pressures differ across the investigated localities. It would be desirable to rotate or apply formulations of combined products with different modes of action. Doing so would enable a better management of resistant homozygous individuals, and mitigate the resistance effect of commonly used insecticides.
Collapse
|
34
|
Chen YA, Lien JC, Tseng LF, Cheng CF, Lin WY, Wang HY, Tsai KH. Effects of indoor residual spraying and outdoor larval control on Anopheles coluzzii from São Tomé and Príncipe, two islands with pre-eliminated malaria. Malar J 2019; 18:405. [PMID: 31806029 PMCID: PMC6896513 DOI: 10.1186/s12936-019-3037-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/26/2019] [Indexed: 12/17/2022] Open
Abstract
Background Vector control is a key component of malaria prevention. Two major vector control strategies have been implemented in São Tomé and Príncipe (STP), indoor residual spraying (IRS) and outdoor larval control using Bacillus thuringiensis israelensis (Bti). This study evaluated post-intervention effects of control strategies on vector population density, composition, and knockdown resistance mutation, and their implications for malaria epidemiology in STP. Methods Mosquitoes were collected by indoor and outdoor human landing catches and mosquito light traps in seven districts. Mosquito density was calculated by numbers of captured adult mosquitoes/house/working hour. Mitochondrial cytochrome c oxidase subunit I (COI) was PCR amplified and sequenced to understand the spatial–temporal population composition of malaria vector in STP. Knockdown resistance L1014F mutation was detected using allele-specific PCR. To estimate the malaria transmission risks in STP, a negative binomial regression model was constructed. The response variable was monthly incidence, and the explanatory variables were area, rainfall, entomological inoculation rate (EIR), and kdr mutation frequency. Results Malaria vector in STP is exophilic Anopheles coluzzii with significant population differentiation between Príncipe and São Tomé (mean FST = 0.16, p < 0.001). Both vector genetic diversity and knockdown resistance mutation were relatively low in Príncipe (mean of kdr frequency = 15.82%) compared to São Tomé (mean of kdr frequency = 44.77%). Annual malaria incidence rate in STP had been rapidly controlled from 37 to 2.1% by three rounds of country-wide IRS from 2004 to 2007. Long-term application of Bti since 2007 kept the mosquito density under 10 mosquitoes/house/hr/month, and malaria incidence rate under 5% after 2008, except for a rising that occurred in 2012 (incidence rate = 6.9%). Risk factors of area (São Tomé compared to Príncipe), rainfall, outdoor EIR, and kdr mutation frequency could significantly increase malaria incidence by 9.33–11.50, 1.25, 1.07, and 1.06 fold, respectively. Conclusions Indoor residual spraying could rapidly decrease Anopheles density and malaria incidence in STP. Outdoor larval control using Bti is a sustainable approach for controlling local vector with exophilic feature and insecticide resistance problem. Vector control interventions should be intensified especially at the north-eastern part of São Tomé to minimize impacts of outbreaks.
Collapse
Affiliation(s)
- Ying-An Chen
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Jih-Ching Lien
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan. .,Taiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe.
| | - Lien-Fen Tseng
- Taiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe
| | - Chien-Fu Cheng
- Taiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe
| | - Wan-Yu Lin
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.,Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Hurng-Yi Wang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kun-Hsien Tsai
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan. .,Taiwan Anti-Malaria Advisory Mission, São Tomé, São Tomé and Príncipe. .,Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
35
|
Djamouko-Djonkam L, Mounchili-Ndam S, Kala-Chouakeu N, Nana-Ndjangwo SM, Kopya E, Sonhafouo-Chiana N, Talipouo A, Ngadjeu CS, Doumbe-Belisse P, Bamou R, Toto JC, Tchuinkam T, Wondji CS, Antonio-Nkondjio C. Spatial distribution of Anopheles gambiae sensu lato larvae in the urban environment of Yaoundé, Cameroon. Infect Dis Poverty 2019; 8:84. [PMID: 31594541 PMCID: PMC6784347 DOI: 10.1186/s40249-019-0597-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 09/10/2019] [Indexed: 11/23/2022] Open
Abstract
Background The rapid and unplanned urbanization of African cities is considered to increase the risk of urban malaria transmission. The present study objective was to assess factors influencing the spatio-temporal distribution of Anopheles gambiae s.l. larvae in the city of Yaoundé, Cameroon. Methods All water bodies were checked once every 2 months for the presence of mosquito larvae from March 2017 to May 2018 in 32 districts of Yaoundé. Physico-chemical characteristics including the size, depth, turbidity, pH, temperature, conductivity, sulfates, organophosphates, hydrogen peroxide (H2O2), conductivity, iron and calcium were recorded and analyzed according to anopheline larvae presence or absence. High resolution satellite images from landsat sentinel Enhanced Thematic Mapper were used for spatial mapping of both field and environmental variables. Bivariate and multivariate logistic regression models were used to identify variables closely associated with anopheline larvae distribution. Results A total of 18 696 aquatic habitats were checked and only 2942 sites (15.7%) contained anopheline larvae. A high number of sites with anopheline larvae (≥ 69%) presented late instar larvae (L3, L4 and pupae). Anopheline mosquito larvae were sampled from a variety of breeding sites including puddles (51.6%), tire prints (12.9%), wells (11.7%) and drains (11.3%). Bivariate logistic regression analyses associated anopheline larvae presence with the absence of predators, absence of algae, absence of vegetation and depth of less than 1 m. Conductivity, turbidity, organophosphates, H2O2 and temperature were significantly high in breeding sites with anopheline larvae than in breeding sites without these larvae (P < 0.1). Anopheline species collected included An. coluzzii (91.1%) and An. gambiae s.s. (8.9%). GIS mapping indicated a heterogeneous distribution of anopheline breeding habitats in the city of Yaoundé. Land cover analysis indicated high variability of the city of Yaoundé’s landscape. Conclusions The data confirms adaptation of An. gambiae s.l. to the urban domain in the city of Yaoundé and calls for urgent actions to improve malaria vector control.
Collapse
Affiliation(s)
- Landre Djamouko-Djonkam
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Souleman Mounchili-Ndam
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Nelly Kala-Chouakeu
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Stella Mariette Nana-Ndjangwo
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Edmond Kopya
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Nadége Sonhafouo-Chiana
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Health Sciences University of Buea, P.O. Box 63, Buea, Cameroon
| | - Abdou Talipouo
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Carmene Sandra Ngadjeu
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Patricia Doumbe-Belisse
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Faculty of Science, University of Yaounde I, P.O. Box 337, Yaounde, Cameroon
| | - Roland Bamou
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon.,Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Jean Claude Toto
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon
| | - Timoléon Tchuinkam
- Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | | | - Christophe Antonio-Nkondjio
- Malaria Research Laboratory, Organization for the fight against Endemic diseases in Central Africa (OCEAC), P.O. Box 288, Yaoundé, Cameroon. .,Vector Biology Liverpool School of Tropical medicine Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
36
|
Collins KA, Ouedraogo A, Guelbeogo WM, Awandu SS, Stone W, Soulama I, Ouattara MS, Nombre A, Diarra A, Bradley J, Selvaraj P, Gerardin J, Drakeley C, Bousema T, Tiono A. Investigating the impact of enhanced community case management and monthly screening and treatment on the transmissibility of malaria infections in Burkina Faso: study protocol for a cluster-randomised trial. BMJ Open 2019; 9:e030598. [PMID: 31519680 PMCID: PMC6747640 DOI: 10.1136/bmjopen-2019-030598] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION A large proportion of malaria-infected individuals in endemic areas do not experience symptoms that prompt treatment-seeking. These asymptomatically infected individuals may retain their infections for many months during which sexual-stage parasites (gametocytes) are produced that may be transmissible to mosquitoes. Reductions in malaria transmission could be achieved by detecting and treating these infections early. This study assesses the impact of enhanced community case management (CCM) and monthly screening and treatment (MSAT) on the prevalence and transmissibility of malaria infections. METHODS AND ANALYSIS This cluster-randomised trial will take place in Sapone, an area of intense, highly seasonal malaria in Burkina Faso. In total, 180 compounds will be randomised to one of three interventions: arm 1 - current standard of care with passively monitored malaria infections; arm 2 - standard of care plus enhanced CCM, comprising active weekly screening for fever, and detection and treatment of infections in fever positive individuals using conventional rapid diagnostic tests (RDTs); or arm 3 - standard of care and enhanced CCM, plus MSAT using RDTs. The study will be conducted over approximately 18 months covering two high-transmission seasons and the intervening dry season. The recruitment strategy aims to ensure that overall transmission and force of infection is not affected so we are able to continuously evaluate the impact of interventions in the context of ongoing intense malaria transmission. The main objectives of the study are to determine the impact of enhanced CCM and MSAT on the prevalence and density of parasitaemia and gametocytaemia and the transmissibility of infections. This will be achieved by molecular detection of infections in all study participants during start and end season cross-sectional surveys and routine sampling of malaria-positive individuals to assess their infectiousness to mosquitoes. ETHICS AND DISSEMINATION The study has been reviewed and approved by the London School of Hygiene and Tropical Medicine (LSHTM) (Review number: 14724) and The Centre National de Recherche et de Formation sur le Paludisme institutional review board (IRB) (Deliberation N° 2018/000002/MS/SG/CNRFP/CIB) and Burkina Faso national medical ethics committees (Deliberation N° 2018-01-010).Findings of the study will be shared with the community via local opinion leaders and community meetings. Results may also be shared through conferences, seminars, reports, theses and peer-reviewed publications; disease occurrence data and study outcomes will be shared with the Ministry of Health. Data will be published in an online digital repository. TRIAL REGISTRATION NUMBER NCT03705624.
Collapse
Affiliation(s)
| | - Alphonse Ouedraogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Wamdaogo Moussa Guelbeogo
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Shehu S Awandu
- Department or Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Will Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Issiaka Soulama
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Maurice S Ouattara
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Apollinaire Nombre
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - John Bradley
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - Teun Bousema
- Department or Medical Microbiology, Radboudumc, Nijmegen, The Netherlands
| | - Alfred Tiono
- Department of Biomedical Sciences, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| |
Collapse
|
37
|
Mulatier M, Pennetier C, Porciani A, Chandre F, Dormont L, Cohuet A. Prior contact with permethrin decreases its irritancy at the following exposure among a pyrethroid-resistant malaria vector Anopheles gambiae. Sci Rep 2019; 9:8177. [PMID: 31160750 PMCID: PMC6546682 DOI: 10.1038/s41598-019-44633-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/21/2019] [Indexed: 11/26/2022] Open
Abstract
Insecticide-treated nets (ITNs) remain major components for vector control despite the spread of resistance mechanisms among mosquito populations. Multiple exposures to pyrethroids may induce physiological and behavioral changes in mosquitoes, possibly reducing efficacy of control tools. Despite epidemiological relevance, the effects of multiple exposures to pyrethroids on their efficacy against pyrethroid-resistant mosquitoes has received little interest. In the present study, we assessed the effects of a blood-meal successfully obtained upon a permethrin-treated net on the success at taking a second blood-meal in presence of permethrin in Anopheles gambiae, carrying pyrethroid resistance alleles. We also measured the impact of exposure to permethrin on life-history traits to address the delayed efficacy of ITNs. Our results showed that females that successfully blood-fed upon a permethrin-treated net were no longer inhibited by permethrin at the following exposure. Blood-meal inhibition due to permethrin was not affected by female size nor by exposure of mothers when testing the offspring, allowing to discard the effect of genetic or physiological selection. Besides, in our assays, exposure to permethrin did not affect mosquito fecundity, fertility nor survival. These results give insights to understand the long-term efficacy of ITNs, and allow to reevaluate the criteria used when choosing compounds for fighting malaria mosquitoes.
Collapse
Affiliation(s)
- Margaux Mulatier
- MIVEGEC, IRD, CNRS, Univ. Montpellier, Montpellier, France. .,CEFE, Univ Paul Valéry Montpellier 3, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France.
| | - Cédric Pennetier
- MIVEGEC, IRD, CNRS, Univ. Montpellier, Montpellier, France.,Institut Pierre Richet, Bouaké, Côte d'Ivoire
| | | | | | - Laurent Dormont
- CEFE, Univ Paul Valéry Montpellier 3, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | - Anna Cohuet
- Institut Pierre Richet, Bouaké, Côte d'Ivoire
| |
Collapse
|
38
|
Tan WL, Li CX, Lv RC, Dong YD, Guo XX, Xing D, Zhou MH, Xu Y, Chu HL, Wang G, Zhu CQ, Sun J, Zhao TY. The polymorphism and geographical distribution of knockdown resistance of adult Anopheles sinensis populations in eastern China. Malar J 2019; 18:164. [PMID: 31064367 PMCID: PMC6505223 DOI: 10.1186/s12936-019-2793-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 04/25/2019] [Indexed: 12/03/2022] Open
Abstract
Background Anopheles sinensis is one of the major malaria vectors in China and other southeast Asian countries, including Vietnam, Cambodia, Thailand. Vector control is considered to be the critical measure for malaria control, while the increasing prevalence of insecticide resistance caused by long-term use of insecticides, especially pyrethroids, is threatening the successful control of An. sinensis. In order to understand the underlying resistance mechanisms involved and molecular basis, the principal malaria vector, An. sinensis from Jiangsu and Anhui provinces, Southeast China, was investigated. Methods The adult Anopheles mosquitoes were sampled from multiple sites across Jiangsu and Anhui provinces, and sufficient mosquitoes collected from eleven sites for insecticide susceptibility bioassays. The DIIS4–DIIS6 region of the para-type sodium channel gene was amplified and sequenced, then multiple PCR and Taqman assays were used to assess the frequencies of kdr mutations at the target gene. Results In the present study, most of the adult An. sinensis populations were pyrethroids resistant, which indicated the presence of kdr resistance mutations in the para-type sodium channel gene. Sequence analyses demonstrated the kdr mutation existed at codon 1014 in Jiangsu and Anhui provinces. In adult An. sinensis, three mutant types (TTT L1014F, TTC L1014F, and TGT L1014C) of kdr alleles were detected, while no wild type (TTG L1014) was observed. The TTC L1014F mutation was first reported in Anhui province. Conclusions The highly polymorphic kdr alleles were observed in all the adult An. sinensis populations, which suggested that in-depth studies are required for carrying on insecticide resistance monitoring and specific resistance mechanisms studying into establish effective long-term malaria vector control program in eastern China.
Collapse
Affiliation(s)
- Wei-Long Tan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.,Department of Vector Control, Huadong Research Institute for Medicine and Biotechnics, Nanjing, 210002, Jiangsu, China
| | - Chun-Xiao Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Rui-Chen Lv
- Department of Vector Control, Huadong Research Institute for Medicine and Biotechnics, Nanjing, 210002, Jiangsu, China
| | - Yan-De Dong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Xiao-Xia Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Dan Xing
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ming-Hao Zhou
- Department of Vector Control, Jiangsu Center for Disease Prevention and Control, Nanjing, Jiangsu, China
| | - Yan Xu
- Department of Vector Control, Jiangsu Center for Disease Prevention and Control, Nanjing, Jiangsu, China
| | - Hong-Liang Chu
- Department of Vector Control, Jiangsu Center for Disease Prevention and Control, Nanjing, Jiangsu, China
| | - Gang Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Chang-Qiang Zhu
- Department of Vector Control, Huadong Research Institute for Medicine and Biotechnics, Nanjing, 210002, Jiangsu, China
| | - Jun Sun
- Department of Vector Control, Jiangsu Center for Disease Prevention and Control, Nanjing, Jiangsu, China.
| | - Tong-Yan Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
| |
Collapse
|
39
|
Wangrawa DW, Badolo A, Ilboudo Z, Guelbéogo WM, Kiendrébeogo M, Nébié RCH, Sagnon N, Sanon A. Insecticidal Activity of Local Plants Essential Oils Against Laboratory and Field Strains of Anopheles gambiae s. l. (Diptera: Culicidae) From Burkina Faso. JOURNAL OF ECONOMIC ENTOMOLOGY 2018; 111:2844-2853. [PMID: 30281085 DOI: 10.1093/jee/toy276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Indexed: 06/08/2023]
Abstract
The emergence and intensification of resistance to insecticides in malaria vector populations is the main obstacle to insecticide-based control efforts. The main objective of this study was to evaluate the larvicidal and adulticidal properties of the essential oils (EOs) of Ocimum canum, Hyptis suaveolens, Hyptis spicigera, and Lantana camara on field-collected, pyrethroids-resistant mosquitoes, local laboratory strains, and susceptible 'Kisumu' strain of Anopheles gambiae (Meigen) (Diptera: Culicidae) populations. Larvae and adults of these mosquitoes were challenged against four EOs. The mortality rates of larvae and adults were assessed 24 h after exposure to the EOs. Species identifications and detection of the L1014F and L1014S kdr mutations and the 1575Y super-kdr mutation were carried out using polymerase chain reaction on the pyrethroid-resistant mosquitoes from the field. EO compositions were analyzed by gas chromatography and mass spectrometry. Monoterpene hydrocarbons were the major components of H. suaveolens and H. spicigera EOs (49.8%) and (69.6%), respectively, whereas oxygenated monoterpenes (68.7%) were predominant in the O. canum EO. For L. camara, the component yields were variable, but it was the most effective EO against all strains. The LC50 values for the larvae were 7.73 and 25.63 ppm for the susceptible 'Kisumu' and resistant field strains, respectively. The LC50 for adults was 0.24% for the susceptible strain and 1.98% for the resistant strain. Molecular analysis confirmed the presence of L1014F and N1575Y mutations in resistant Anopheles arabiensis and Anopheles coluzzii mosquitoes from the field. Our results highlighted the potential of the EOs of local plants as insecticides against resistant and susceptible strains of An. gambiae populations.
Collapse
Affiliation(s)
- Dimitri Wendgida Wangrawa
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Ouaga I Pr Joseph, Ouagadougou, Burkina Faso
- Unité de Formation et de Recherches/Sciences et Technologies, Université Norbert ZONGO, Koudougou, Burkina Faso
| | - Athanase Badolo
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Ouaga I Pr Joseph, Ouagadougou, Burkina Faso
| | - Zakaria Ilboudo
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Ouaga I Pr Joseph, Ouagadougou, Burkina Faso
| | | | - Martin Kiendrébeogo
- Laboratoire de Biochimie et de Chimie Appliquée, Université Ouaga I Pr Joseph, Ouagadougou 03, Burkina Faso
| | | | - N'Falé Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Antoine Sanon
- Laboratoire d'Entomologie Fondamentale et Appliquée, Université Ouaga I Pr Joseph, Ouagadougou, Burkina Faso
| |
Collapse
|
40
|
Awolola TS, Adeogun A, Olakiigbe AK, Oyeniyi T, Olukosi YA, Okoh H, Arowolo T, Akila J, Oduola A, Amajoh CN. Pyrethroids resistance intensity and resistance mechanisms in Anopheles gambiae from malaria vector surveillance sites in Nigeria. PLoS One 2018; 13:e0205230. [PMID: 30517090 PMCID: PMC6281219 DOI: 10.1371/journal.pone.0205230] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 09/22/2018] [Indexed: 11/18/2022] Open
Abstract
Anopheles gambiae, An. coluzzii and An. arabiensis are the three major vectors of malaria in Nigeria. These mosquitoes have developed resistance to different insecticides. Insecticides resistance intensity assay was recently introduced to provide insight into the potential operational significance of insecticide resistance. Here, we present data on pyrethroids resistance intensity and resistance mechanisms from six vector surveillance sites (Lagos, Ogun, Edo, Anambra, Kwara and Niger) in Nigeria. Adult Anopheles reared from larval collections were tested using WHO insecticides susceptibility protocol with 1x concentration of permethrin and deltamethrin followed with intensity assays with 5x and 10x concentrations of both insecticides. Synergistic and biochemical assays were carried out and underlying resistance mechanisms determined following standard protocols. Anopheles gambiae constituted >50% samples tested in five sites. Permethrin and deltamethrin resistance was observed at all the sites. The Kdt50 varied from 15 minutes (CI = 13.6-17.2) in deltamethrin to 42.1 minutes (CI = 39.4-44.1) in permethrin. For both insecticides, Kdt95 was >30 minutes with 25% to 87% post exposure mortality at the different sites. The West Africa knock down resistance (kdr-w) mechanism was found at each site. Resistant An. gambiae from Lagos, Ogun and Niger synergized prior to permethrin or deltamethrin exposure showed significant mortality (89-100%) compared to unsynergized mosquitoes (Lagos, p = 0.031; Ogun, p = 0.025; Niger, p = 0.018). Biochemical analyses revealed significant increased levels of P450 enzymes in resistant Anopheles gambiae from Lagos (p = 0.038); Ogun (p = 0.042) and Niger (p = 0.028) in addition to GST in Lagos (p = 0.028) and Ogun (p = 0.033). Overall, the results revealed high pyrethroid resistance associated with increased activities of metabolic enzymes (P450 + GST) in An. gambiae and An. coluzzii from Lagos and Ogun. The presence of kdr + P450 conferred moderate resistance whereas low resistance was the case where kdr was the sole resistance mechanism. Findings thus suggests that elevated levels of cytochrome P450 enzymes together with GST were responsible for high or severe pyrethroid resistance.
Collapse
Affiliation(s)
- Taiwo Samson Awolola
- Nigerian Institute of Medical Research, 6 Edmund Crescent, Yaba, Lagos, Nigeria
- * E-mail:
| | - Adedapo Adeogun
- Nigerian Institute of Medical Research, 6 Edmund Crescent, Yaba, Lagos, Nigeria
| | | | - Tolulope Oyeniyi
- Nigerian Institute of Medical Research, 6 Edmund Crescent, Yaba, Lagos, Nigeria
| | | | - Hilary Okoh
- Department of Biological Sciences, Federal University Oye, Oye, Ekiti State, Nigeria
| | | | - Joel Akila
- National Malaria Elimination Program, Federal Ministry of Health, Abuja, Nigeria
| | - Adedayo Oduola
- Department of Zoology, University of Ilorin, Ilorin, Kwara State, Nigeria
| | | |
Collapse
|
41
|
Assogba BS, Alout H, Koffi A, Penetier C, Djogbénou LS, Makoundou P, Weill M, Labbé P. Adaptive deletion in resistance gene duplications in the malaria vector Anopheles gambiae. Evol Appl 2018; 11:1245-1256. [PMID: 30151037 PMCID: PMC6099818 DOI: 10.1111/eva.12619] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/15/2018] [Indexed: 12/11/2022] Open
Abstract
While gene copy-number variations play major roles in long-term evolution, their early dynamics remains largely unknown. However, examples of their role in short-term adaptation are accumulating: identical repetitions of a locus (homogeneous duplications) can provide a quantitative advantage, while the association of differing alleles (heterogeneous duplications) allows carrying two functions simultaneously. Such duplications often result from rearrangements of sometimes relatively large chromosome fragments, and even when adaptive, they can be associated with deleterious side effects that should, however, be reduced by subsequent evolution. Here, we took advantage of the unique model provided by the malaria mosquito Anopheles gambiae s.l. to investigate the early evolution of several duplications, heterogeneous and homogeneous, segregating in natural populations from West Africa. These duplications encompass ~200 kb and 11 genes, including the adaptive insecticide resistance ace-1 locus. Through the survey of several populations from three countries over 3-4 years, we showed that an internal deletion of all coamplified genes except ace-1 is currently spreading in West Africa and introgressing from An. gambiae s.s. to An. coluzzii. Both observations provide evidences of its selection, most likely due to reducing the gene-dosage disturbances caused by the excessive copies of the nonadaptive genes. Our study thus provides a unique example of the early adaptive trajectory of duplications and underlines the role of the environmental conditions (insecticide treatment practices and species ecology). It also emphasizes the striking diversity of adaptive responses in these mosquitoes and reveals a worrisome process of resistance/cost trade-off evolution that could impact the control of malaria vectors in Africa.
Collapse
Affiliation(s)
- Benoît S. Assogba
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS‐UM‐IRD‐EPHE)Université de MontpellierMontpellierFrance
- Disease Control and Elimination DepartmentMedical Research Council, Unit The GambiaBanjulThe Gambia
- Institut Régional de Santé PubliqueUniversité d'Abomey CalaviCotonouBenin
- Faculté des Sciences et TechniquesLaboratoire de Biologie et de Typage Moléculaire en MicrobiologieUniversité d'Abomey CalaviCotonouBénin
| | - Haoues Alout
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS‐UM‐IRD‐EPHE)Université de MontpellierMontpellierFrance
| | - Alphonsine Koffi
- Institut Pierre Richet (IPR)/Institut National de Santé Publique (INSP)BouakéCôte d'Ivoire
| | - Cédric Penetier
- Institut de Recherche pour le Développement (IRD)UMR MIVEGECMontpellierFrance
| | - Luc S. Djogbénou
- Institut Régional de Santé PubliqueUniversité d'Abomey CalaviCotonouBenin
- Faculté des Sciences et TechniquesLaboratoire de Biologie et de Typage Moléculaire en MicrobiologieUniversité d'Abomey CalaviCotonouBénin
| | - Patrick Makoundou
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS‐UM‐IRD‐EPHE)Université de MontpellierMontpellierFrance
| | - Mylène Weill
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS‐UM‐IRD‐EPHE)Université de MontpellierMontpellierFrance
| | - Pierrick Labbé
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS‐UM‐IRD‐EPHE)Université de MontpellierMontpellierFrance
| |
Collapse
|
42
|
Bamou R, Mbakop LR, Kopya E, Ndo C, Awono-Ambene P, Tchuinkam T, Rono MK, Mwangangi J, Antonio-Nkondjio C. Changes in malaria vector bionomics and transmission patterns in the equatorial forest region of Cameroon between 2000 and 2017. Parasit Vectors 2018; 11:464. [PMID: 30103825 PMCID: PMC6090627 DOI: 10.1186/s13071-018-3049-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 08/02/2018] [Indexed: 11/22/2022] Open
Abstract
Background Increased use of long-lasting insecticidal nets (LLINs) over the last decade has considerably improved the control of malaria in sub-Saharan Africa. However, there is still a paucity of data on the influence of LLIN use and other factors on mosquito bionomics in different epidemiological foci. The objective of this study was to provide updated data on the evolution of vector bionomics and malaria transmission patterns in the equatorial forest region of Cameroon over the period 2000–2017, during which LLIN coverage has increased substantially. Methods The study was conducted in Olama and Nyabessan, two villages situated in the equatorial forest region. Mosquito collections from 2016–2017 were compared to those of 2000–2001. Mosquitoes were sampled using both human landing catches and indoor sprays, and were identified using morphological taxonomic keys. Specimens belonging to the An. gambiae complex were further identified using molecular tools. Insecticide resistance bioassays were undertaken on An. gambiae to assess the susceptibility levels to both permethrin and deltamethrin. Mosquitoes were screened for Plasmodium falciparum infection and blood-feeding preference using the ELISA technique. Parasitological surveys in the population were conducted to determine the prevalence of Plasmodium infection using rapid diagnostic tests. Results A change in the species composition of sampled mosquitoes was recorded between the 2000–2001 collections and those of 2016–2017. A drop in the density of the local primary vectors An. nili and An. moucheti in the forest region was recorded, whereas there was an increase in the density of An. gambiae (s.l.), An. marshallii, An. ziemannii and An. paludis. A change in the biting behaviour from indoor to outdoor was recorded in Olama. Very few indoor resting mosquitoes were collected. A change in the night biting cycle was recorded with mosquitoes displaying a shift from night biting to late evening/early in the night. Several mosquitoes were found positive for Plasmodium infection, thus sustaining continuous transmission of malaria in both sites. Reduction of malaria transmission in Nyabessan was lower than that seen in Olama and associated with deforestation and the construction of a dam that may have enabled a more efficient vector, An. gambiae (s.l.), to invade the area. A high level of resistance to pyrethroids (permethrin and deltamethrin) was detected for An. gambiae in both sites. High parasite prevalence was recorded in both sites, with children of 0–16 years being the most affected. In both Olama and Nyabessan, bed net usage appeared to correlate to protection against malaria infection. Conclusions The study shows important changes in the bionomics of vector populations and malaria transmission patterns in the equatorial forest region. The changes call for more concerted efforts to address challenges such as insecticide resistance, environmental modifications or behavioural changes affecting the performance of current control measures.
Collapse
Affiliation(s)
- Roland Bamou
- Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science of the University of Dschang, P. O. Box 067, Dschang, Cameroon.,Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon
| | - Lili Ranaise Mbakop
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Edmond Kopya
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon.,Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Cyrille Ndo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon.,Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon.,Vector Biology Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon
| | - Timoleon Tchuinkam
- Vector Borne Infectious Disease Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Science of the University of Dschang, P. O. Box 067, Dschang, Cameroon
| | - Martin Kibet Rono
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research Coast, Kilifi, Kenya.,KEMRI-Centre for Geographic Medicine Research Kilifi, Kilifi, Kenya
| | - Joseph Mwangangi
- KEMRI-Centre for Geographic Medicine Research Kilifi, Kilifi, Kenya.,Pwani University Health and Research Institute, Pwani University, Kilifi, Kenya
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B. P.288, Yaoundé, Cameroon. .,Vector Biology Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
43
|
Djènontin A, Moiroux N, Bouraïma A, Zogo B, Sidick I, Corbel V, Pennetier C. Field efficacy of a new deltamethrin long lasting insecticidal net (LifeNet©) against wild pyrethroid-resistant Anopheles gambiae in Benin. BMC Public Health 2018; 18:947. [PMID: 30068334 PMCID: PMC6090760 DOI: 10.1186/s12889-018-5876-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/24/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malaria vector control is mostly based on Long-Lasting Insecticidal Nets (LLIN). To date, all LLINs fully recommended by the World Health Organization Pesticide Scheme (WHOPES) are made of polyester or polyethylene. In this context, a new LLIN named LifeNet©, made of polypropylene fiber is developed. According to the manufacturer, LifeNet©is made of soft filament, has a greater mechanical strength, a superior insecticide wash resistance with a short insecticide regeneration time, a better flammability profile and a better environmental profile compared to polyester or polyethylene nets. METHODS Through a WHOPES supervised trial, the efficacy of LifeNet© was evaluated in Benin in experimental huts against free-flying wild mosquitoes. RESULTS LifeNet© has equal or better performances in terms of wash resistance, exophily, blood feeding inhibition and mortality compared to conventionally treated nets (CTN) treated with deltamethrin at 25 mg/m2 and washed to just before exhaustion. CONCLUSIONS The efficacy of LifeNet© observed in this trial indicates that this net fulfill World Health Organization Pesticide Scheme (WHOPES) requirement for Long Lasting technology in Phase II. Throughout a Phase III trial currently ongoing in Southern Benin, the durability and the acceptability of this long-lasting insecticidal mosquito nets will be assessed under community conditions.
Collapse
Affiliation(s)
- Armel Djènontin
- Faculté des Sciences et Techniques-Université d’Abomey-Calavi, Cotonou, Benin
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Nicolas Moiroux
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
- IRSS, CNRST, Bobo Dioulasso, Ouagadougou, Burkina Faso
| | - Aziz Bouraïma
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
| | - Barnabas Zogo
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
| | | | - Vincent Corbel
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
| | - Cédric Pennetier
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
- IPR, INSP, Bouaké, Côte d’Ivoire
| |
Collapse
|
44
|
Hancock PA, Wiebe A, Gleave KA, Bhatt S, Cameron E, Trett A, Weetman D, Smith DL, Hemingway J, Coleman M, Gething PW, Moyes CL. Associated patterns of insecticide resistance in field populations of malaria vectors across Africa. Proc Natl Acad Sci U S A 2018; 115:5938-5943. [PMID: 29784773 PMCID: PMC6003363 DOI: 10.1073/pnas.1801826115] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The development of insecticide resistance in African malaria vectors threatens the continued efficacy of important vector control methods that rely on a limited set of insecticides. To understand the operational significance of resistance we require quantitative information about levels of resistance in field populations to the suite of vector control insecticides. Estimation of resistance is complicated by the sparsity of observations in field populations, variation in resistance over time and space at local and regional scales, and cross-resistance between different insecticide types. Using observations of the prevalence of resistance in mosquito species from the Anopheles gambiae complex sampled from 1,183 locations throughout Africa, we applied Bayesian geostatistical models to quantify patterns of covariation in resistance phenotypes across different insecticides. For resistance to the three pyrethroids tested, deltamethrin, permethrin, and λ-cyhalothrin, we found consistent forms of covariation across sub-Saharan Africa and covariation between resistance to these pyrethroids and resistance to DDT. We found no evidence of resistance interactions between carbamate and organophosphate insecticides or between these insecticides and those from other classes. For pyrethroids and DDT we found significant associations between predicted mean resistance and the observed frequency of kdr mutations in the Vgsc gene in field mosquito samples, with DDT showing the strongest association. These results improve our capacity to understand and predict resistance patterns throughout Africa and can guide the development of monitoring strategies.
Collapse
Affiliation(s)
- Penelope A Hancock
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF Oxford, United Kingdom;
| | - Antoinette Wiebe
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF Oxford, United Kingdom
| | - Katherine A Gleave
- Department of Vector Biology, Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - Samir Bhatt
- Department of Infectious Disease Epidemiology, St Mary's Hospital, Imperial College, W2 1NY London, United Kingdom
| | - Ewan Cameron
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF Oxford, United Kingdom
| | - Anna Trett
- Department of Vector Biology, Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - David L Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA 98121
| | - Janet Hemingway
- Department of Vector Biology, Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom;
| | - Michael Coleman
- Department of Vector Biology, Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - Peter W Gething
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF Oxford, United Kingdom
| | - Catherine L Moyes
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF Oxford, United Kingdom;
| |
Collapse
|
45
|
Djègbè I, Akoton R, Tchigossou G, Ahadji-Dabla KM, Atoyebi SM, Adéoti R, Zeukeng F, Ketoh GK, Djouaka R. First report of the presence of L1014S Knockdown-resistance mutation in Anopheles gambiae s.s and Anopheles coluzzii from Togo, West Africa. Wellcome Open Res 2018; 3:30. [PMID: 29707654 PMCID: PMC5909049 DOI: 10.12688/wellcomeopenres.13888.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2018] [Indexed: 11/30/2022] Open
Abstract
Background: To optimize the success of insecticide-based malaria control intervention, knowledge of the distribution of Anopheles gambiae species and insecticide resistance mechanisms is necessary. This paper reported an updated data on pyrethroids/DDT resistance in the An. gambiae s.l population from Togo. Methods: From December 2013 to April 2015, females of indoor-resting An. gambiae s.l were captured in three locations belonging to three different ecological zones. Resistance to DDT, permethrin and deltamethrin was screened in F1 progeny of collected mosquitoes using WHO susceptibility tests. The identification of species of An. gambiae complex and the detection of kdr and ace.1 R allele were carried out using DNA-based molecular techniques. Results:An. gambiae from Kovié and Nangbéto were highly resistant to DDT and permethrin with mortalities rate ranging from 0.83% to 1.58% for DDT and zero to 8.54% for permethrin. Mosquitoes collected in Nangbéto displayed 81.53% mortality with deltamethrin. An. coluzzii and An. gambiae s.s were found in sympatry in Nangbéto and Mango . The allelic frequency of L1014F was high, ranging from 66 to 100% in both An. coluzzii and An. gambiae s.s. For the first time we detected the L1014S allele in both An. coluzzii and An. gambiaes.s. from Togo at the frequency ranging from 5% to 13% in all the sites. The kdr N1575Y was present at various frequencies in both species ranging from 10% to 45%. Both An. gambiae s.s. and An. coluzzii shared the ace1 R mutation in all investigated sites with allelic frequency ranging from 4% to 16%. Conclusion: These results showed that multiple mutations are involved in insecticides resistance in An. gambiae populations from Togo including the kdr L1014F, L1014S, and N1575Y and ace.1 R G119S mutations.
Collapse
Affiliation(s)
- Innocent Djègbè
- University of Sciences, Technologies and Mathematics, Ecole Normale Supérieure de Natitingou, Natitingou, BP 123, Benin
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Romaric Akoton
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, BP 526, Benin
| | - Genevieve Tchigossou
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, BP 526, Benin
| | | | - Seun Michael Atoyebi
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Razack Adéoti
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Francis Zeukeng
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, BP 812, Cameroon
| | - Guillaume Koffivi Ketoh
- Research unit of Ecotoxicology, Faculty of Sciences, University of Lomé, Lomé, 01 BP 1515 , Togo
| | - Rousseau Djouaka
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| |
Collapse
|
46
|
Silva GLD, Pereira TN, Ferla NJ, Silva OSD. The impact of insecticides management linked with resistance expression in Anopheles spp. populations. CIENCIA & SAUDE COLETIVA 2018; 21:2179-88. [PMID: 27383351 DOI: 10.1590/1413-81232015217.00922015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 06/11/2015] [Indexed: 11/22/2022] Open
Abstract
The resistance of some species of Anopheles to chemical insecticides is spreading quickly throughout the world and has hindered the actions of prevention and control of malaria. The main mechanism responsible for resistance in these insects appears to be the target site known as knock-down resistance (kdr), which causes mutations in the sodium channel. Even so, many countries have made significant progress in the prevention of malaria, focusing largely on vector control through long-lasting insecticide nets (LLINs), indoor residual spraying and (IRS) of insecticides. The objective of this review is to contribute with information on the more applied insecticides for the control of the main vectors of malaria, its effects, and the different mechanisms of resistance. Currently it is necessary to look for others alternatives, e.g. biological control and products derived from plants and fungi, by using other organisms as a possible regulator of the populations of malaria vectors in critical outbreaks.
Collapse
Affiliation(s)
- Guilherme Liberato da Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul. R. Sarmento Leite 500, Centro Histórico. 90050-170 Porto Alegre RS Brasil.
| | - Thiago Nunes Pereira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul. R. Sarmento Leite 500, Centro Histórico. 90050-170 Porto Alegre RS Brasil.
| | - Noeli Juarez Ferla
- Laboratório de Acarologia, Museu de Ciências Naturais, Centro Universitário UNIVATES. Lajeado RS Brasil
| | - Onilda Santos da Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal do Rio Grande do Sul. R. Sarmento Leite 500, Centro Histórico. 90050-170 Porto Alegre RS Brasil.
| |
Collapse
|
47
|
Kudom AA, Anane LN, Afoakwah R, Adokoh CK. Relating High Insecticide Residues in Larval Breeding Habitats in Urban Residential Areas to the Selection of Pyrethroid Resistance in Anopheles gambiae s.l. (Diptera: Culicidae) in Akim Oda, Ghana. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:490-495. [PMID: 29267961 PMCID: PMC5850513 DOI: 10.1093/jme/tjx223] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Indexed: 06/07/2023]
Abstract
The main objective of this study was to assess insecticide contamination in Anopheles breeding habitats in urban residential areas and pyrethroid susceptibility status of mosquitoes found in the habitats. A larval survey was conducted in Akim Oda between July and October 2016. The larvae that were reared to adult were used for susceptibility test against four different pyrethroid insecticides (deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15%, and etofenprox 0.5%). Gas chromatography was used to analyze pesticide residues in water collected from the breeding habitats. High levels of permethrin and deltamethrin plus traces of several organochlorine and organophosphate insecticides were detected in the larval-breeding habitats. None of the four pyrethroid insecticides caused more than 10% mortality. Anopheles coluzzii Coetzee & Wilkerson dominated in the study area with high frequency of kdr mutation (93.5%). We report for the first time in Ghana, high levels of pyrethroid insecticides contamination in Anopheles breeding habitats in urban residential areas where there are no major agricultural activities. The contamination is suspected to be the major cause of pyrethroid resistance in the Anopheles species. Improper disposal of old insecticide-treated net and other domestic insecticides and the use of herbicides are suspected to be the source of insecticide contamination.
Collapse
Affiliation(s)
- Andreas A Kudom
- Department of Conservation Biology and Entomology, University of Cape Coast, Cape Coast, Ghana
| | - Leticia N Anane
- Department of Biomedical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Richmond Afoakwah
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Christian K Adokoh
- Department of Forensic Sciences, University of Cape Coast, Cape Coast, Ghana
| |
Collapse
|
48
|
Dengela D, Seyoum A, Lucas B, Johns B, George K, Belemvire A, Caranci A, Norris LC, Fornadel CM. Multi-country assessment of residual bio-efficacy of insecticides used for indoor residual spraying in malaria control on different surface types: results from program monitoring in 17 PMI/USAID-supported IRS countries. Parasit Vectors 2018; 11:71. [PMID: 29382388 PMCID: PMC5791726 DOI: 10.1186/s13071-017-2608-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/26/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Indoor residual spraying (IRS) is the application of insecticide to the interior walls of household structures that often serve as resting sites for mosquito vectors of malaria. Human exposure to malaria vectors is reduced when IRS involves proper application of pre-determined concentrations of the active ingredient specific to the insecticide formulation of choice. The impact of IRS can be affected by the dosage of insecticide, spray coverage, vector behavior, vector susceptibility to insecticides, and the residual efficacy of the insecticide applied. This report compiles data on the residual efficacy of insecticides used in IRS campaigns implemented by the United States President's Malaria Initiative (PMI)/United States Agency for International Development (USAID) in 17 African countries and compares observed length of efficacy to ranges proposed in World Health Organization (WHO) guidelines. Additionally, this study provides initial analysis on variation of mosquito mortality depending on the surface material of sprayed structures, country spray program, year of implementation, source of tested mosquitoes, and type of insecticide. METHODS Residual efficacy of the insecticides used for PMI/USAID-supported IRS campaigns was measured in Benin, Burkina Faso, Ethiopia, Ghana, Kenya, Liberia, Madagascar, Malawi, Mali, Mozambique, Nigeria, Rwanda, Senegal, Tanzania, Uganda, Zambia and Zimbabwe. The WHO cone bioassay tests were used to assess the mortality rate of mosquitoes exposed to insecticide-treated mud, wood, cement, and other commonly used housing materials. Baseline tests were performed within weeks of IRS application and follow-up tests were continued until the mortality of exposed mosquitoes dropped below 80% or the program monitoring period ended. Residual efficacy in months was then evaluated with respect to WHO guidelines that provide suggested ranges of residual efficacy for insecticide formulations recommended for use in IRS. Where the data allowed, direct comparisons of mosquito mortality rates were then made to determine any significant differences when comparing insecticide formulation, country, year, surface type, and the source of the mosquitoes used in testing. RESULTS The residual efficacy of alpha-cypermethrin ranged from 4 to 10 months (average = 6.4 months), with no reported incidents of underperformance when compared to the efficacy range provided in WHO guidelines. Deltamethrin residual efficacy results reported a range of 1 to 10 months (average = 4.9 months), with two instances of underperformance. The residual efficacy of bendiocarb ranged from 2 weeks to 7 months (average = 2.8 months) and failed to achieve proposed minimum efficacy on 14 occasions. Lastly, long-lasting pirimiphos-methyl efficacy ranged from 2 months to 9 months (average = 5.3 months), but reported 13 incidents of underperformance. CONCLUSIONS Much of the data used to determine application rate and expected efficacy of insecticides approved for use in IRS programs are collected in controlled laboratory or pilot field studies. However, the generalizability of the results obtained under controlled conditions are limited and unlikely to account for variation in locally sourced housing materials, climate, and the myriad other factors that may influence the bio-efficacy of insecticides. Here, data are presented that confirm the variation in residual efficacy observed when monitoring household surfaces sprayed during PMI/USAID-supported IRS campaigns. All insecticides except alpha-cypermethrin showed evidence of failing to meet the minimum range of residual efficacy proposed in WHO criteria at least once. However, this initial effort in characterizing program-wide insecticide bio-efficacy indicates that some insecticides, such as bendiocarb and pirimiphos-methyl, may be vulnerable to variations in the local environment. Additionally, the comparative analysis performed in this study provides evidence that mosquito mortality rates differ with respect to factors including: the types of insecticide sprayed, surface material, geographical location, year of spraying, and tested mosquitoes. It is, therefore, important to locally assess the residual efficacy of insecticides on various surfaces to inform IRS programming.
Collapse
Affiliation(s)
- Dereje Dengela
- U.S. PMI Africa Indoor Residual Spraying Project, Abt Associates, 4550 Montgomery Ave, Suite 800 N, Bethesda, MD, 20814, USA.
| | - Aklilu Seyoum
- U.S. PMI Africa Indoor Residual Spraying Project, Abt Associates, 4550 Montgomery Ave, Suite 800 N, Bethesda, MD, 20814, USA
| | - Bradford Lucas
- U.S. PMI Africa Indoor Residual Spraying Project, Abt Associates, 4550 Montgomery Ave, Suite 800 N, Bethesda, MD, 20814, USA
| | - Benjamin Johns
- U.S. PMI Africa Indoor Residual Spraying Project, Abt Associates, 4550 Montgomery Ave, Suite 800 N, Bethesda, MD, 20814, USA
| | - Kristen George
- U.S. President's Malaria Initiative USAID, 1300 Pennsylvania Avenue NW, Washington, DC, 20523, USA
| | - Allison Belemvire
- U.S. President's Malaria Initiative USAID, 1300 Pennsylvania Avenue NW, Washington, DC, 20523, USA
| | - Angela Caranci
- U.S. President's Malaria Initiative USAID, 1300 Pennsylvania Avenue NW, Washington, DC, 20523, USA
| | - Laura C Norris
- U.S. President's Malaria Initiative USAID, 1300 Pennsylvania Avenue NW, Washington, DC, 20523, USA
| | - Christen M Fornadel
- U.S. President's Malaria Initiative USAID, 1300 Pennsylvania Avenue NW, Washington, DC, 20523, USA
| |
Collapse
|
49
|
Hemming-Schroeder E, Strahl S, Yang E, Nguyen A, Lo E, Zhong D, Atieli H, Githeko A, Yan G. Emerging Pyrethroid Resistance among Anopheles arabiensis in Kenya. Am J Trop Med Hyg 2018; 98:704-709. [PMID: 29363447 PMCID: PMC5930888 DOI: 10.4269/ajtmh.17-0445] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Vector control programs, particularly in the form of insecticide-treated bed nets (ITNs), are essential for achieving malaria elimination goals. Recent reports of increasing knockdown resistance (kdr) mutation frequencies for Anopheles arabiensis in Western Kenya heightens the concern on the future effectiveness of ITNs in Kenya. We examined resistance in An. arabiensis populations across Kenya through kdr mutations and World Health Organization–recommended bioassays. We detected two kdr alleles, L1014F and L1014S. Kdr mutations were found in five of the 11 study sites, with mutation frequencies ranging from 3% to 63%. In two Western Kenya populations, the kdr L1014F allele frequency was as high as 10%. The L1014S frequency was highest at Chulaimbo at 55%. Notably, the kdr L1014F mutation was found to be associated with pyrethroid resistance at Port Victoria, but kdr mutations were not significantly associated with resistance at Chulaimbo, which had the highest kdr mutation frequency among all sites. This study demonstrated the emerging pyrethroid resistance in An. arabiensis and that pyrethroid resistance may be related to kdr mutations. Resistance monitoring and management are urgently needed for this species in Kenya where resistance is emerging and its abundance is becoming predominant. Kdr mutations may serve as a biomarker for pyrethroid resistance in An. arabiensis.
Collapse
Affiliation(s)
| | - Stephanie Strahl
- Program in Public Health, University of California, Irvine, California
| | - Eugene Yang
- Program in Public Health, University of California, Irvine, California
| | - Amanda Nguyen
- Program in Public Health, University of California, Irvine, California
| | - Eugenia Lo
- Program in Public Health, University of California, Irvine, California
| | - Daibin Zhong
- Program in Public Health, University of California, Irvine, California
| | - Harrysone Atieli
- Centre for Vector Biology and Control Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Andrew Githeko
- Centre for Vector Biology and Control Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, California
| |
Collapse
|
50
|
Camara S, Koffi AA, Ahoua Alou LP, Koffi K, Kabran JPK, Koné A, Koffi MF, N'Guessan R, Pennetier C. Mapping insecticide resistance in Anopheles gambiae (s.l.) from Côte d'Ivoire. Parasit Vectors 2018; 11:19. [PMID: 29310704 PMCID: PMC5759872 DOI: 10.1186/s13071-017-2546-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/21/2017] [Indexed: 11/10/2022] Open
Abstract
Background Insecticide resistance in malaria vectors is an increasing threat to vector control tools currently deployed in endemic countries. Resistance management must be an integral part of National Malaria Control Programmes’ (NMCPs) next strategic plans to alleviate the risk of control failure. This obviously will require a clear database on insecticide resistance to support the development of such a plan. The present work gathers original data on insecticide resistance between 2009 and 2015 across Côte d’Ivoire in West Africa. Methods Two approaches were adopted to build or update the resistance data in the country. Resistance monitoring was conducted between 2013 and 2015 in 35 sentinel sites across the country using the WHO standard procedure of susceptibility test on adult mosquitoes. Four insecticide families (pyrethroids, organochlorides, carbamates and organophosphates) were tested. In addition to this survey, we also reviewed the literature to assemble existing data on resistance between 2009 and 2015. Results High resistance levels to pyrethroids, organochlorides and carbamates were widespread in all study sites whereas some Anopheles populations remained susceptible to organophosphates. Three resistance mechanisms were identified, involving high allelic frequencies of kdr L1014F mutation (range = 0.46–1), relatively low frequencies of ace-1R (below 0.5) and elevated activity of insecticide detoxifying enzymes, mainly mixed function oxidases (MFO), esterase and glutathione S-transferase (GST) in almost all study sites. Conclusion This detailed map of resistance highlights the urgent need to develop new vector control tools to complement current long-lasting insecticidal nets (LLINs) although it is yet unclear whether these resistance mechanisms will impact malaria transmission control. Researchers, industry, WHO and stakeholders must urgently join forces to develop alternative tools. By then, NMCPs must strive to develop effective tactics or plans to manage resistance keeping in mind country-specific context and feasibility.
Collapse
Affiliation(s)
- Soromane Camara
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.,Université Félix Houphouët Boigny (UFHB), 22 BP 582, Abidjan 22, Côte d'Ivoire
| | - Alphonsine A Koffi
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.
| | - Ludovic P Ahoua Alou
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Kouakou Koffi
- Université Félix Houphouët Boigny (UFHB), 22 BP 582, Abidjan 22, Côte d'Ivoire
| | - Jean-Paul K Kabran
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Aboubacar Koné
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Mathieu F Koffi
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Raphaël N'Guessan
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.,London School of Hygiene and Tropical Medicine, London, UK
| | - Cédric Pennetier
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire. .,Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Control (MIVEGEC), UMR 5290 CNRS-IRD-UM, Montpellier, France.
| |
Collapse
|