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Fouet C, Pinch MJ, Ashu FA, Ambadiang MM, Bouaka C, Batronie AJ, Hernandez CA, Rios DE, Penlap-Beng V, Kamdem C. Field-evolved resistance to neonicotinoids in the mosquito, Anopheles gambiae, is associated with downregulation and mutations of nicotinic acetylcholine receptor subunits combined with cytochrome P450-mediated detoxification. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.17.608399. [PMID: 39185195 PMCID: PMC11343199 DOI: 10.1101/2024.08.17.608399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Neonicotinoid insecticides act selectively on their nicotinic receptor targets leading to variable sensitivity among arthropods. This study aimed to investigate the molecular mechanisms underlying contrasting susceptibility to neonicotinoids observed in wild populations of two mosquito sibling species. Bioassays and a synergism test revealed that the sister taxa, Anopheles gambiae and An. coluzzii, from Yaounde, Cameroon, rely on cytochrome P450s to detoxify neonicotinoids and develop resistance. However, contrary to An. coluzzii, An. gambiae populations are evolving stronger resistance to several active ingredients facilitated by mutations and reduced expression of nicotinic acetylcholine receptors. Six mutations were detected in coding sequences of the β1 and α6 subunits, including two substitutions in one of the loops that modulate ligand binding and sensitivity. Allele frequencies were strongly correlated with a susceptibility gradient between An. coluzzii and An. gambiae suggesting that the mutations may play a key role in sensitivity. Messenger RNA expression levels of the β1, α3, and α7 subunits decreased dramatically, on average by 23.27, 17.50, 15.80-fold, respectively, in wild An. gambiae populations compared to a susceptible insectary colony. By contrast, only the β2 and α9-1 subunits were moderately downregulated (5.28 and 2.67-fold change, respectively) in field-collected An. coluzzii adults relative to susceptible colonized mosquitoes. Our findings provide critical information for the application and resistance management of neonicotinoids in malaria prevention.
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Affiliation(s)
- Caroline Fouet
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Matthew J. Pinch
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Fred A. Ashu
- Department of Entomology, Centre for Research in Infectious Diseases, Yaounde, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaounde, Cameroon
| | - Marilene M. Ambadiang
- Department of Entomology, Centre for Research in Infectious Diseases, Yaounde, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaounde, Cameroon
| | - Calmes Bouaka
- Department of Vector Biology, Liverpool School of Tropical Medicine
| | - Anthoni J. Batronie
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Cesar A. Hernandez
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Desiree E. Rios
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Véronique Penlap-Beng
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaounde, Cameroon
| | - Colince Kamdem
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, Texas, USA
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Longo-Pendy NM, Sevidzem SL, Makanga BK, Ndotit-Manguiengha S, Boussougou-Sambe ST, Obame Ondo Kutomy P, Obame-Nkoghe J, Nkoghe-Nkoghe LC, Ngossanga B, Mvoubou FK, Koumba CRZ, Adegnika AA, Razack AS, Mavoungou JF, Mintsa-Nguema R. Assessment of environmental and spatial factors influencing the establishment of Anopheles gambiae larval habitats in the malaria endemic province of Woleu-Ntem, northern Gabon. Malar J 2024; 23:158. [PMID: 38773512 PMCID: PMC11106858 DOI: 10.1186/s12936-024-04980-5] [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: 01/02/2024] [Accepted: 05/10/2024] [Indexed: 05/23/2024] Open
Abstract
BACKGROUND This study aimed to assess the spatial distribution of Anopheles mosquito larval habitats and the environmental factors associated with them, as a prerequisite for the implementation of larviciding. METHODS The study was conducted in December 2021, during the transition period between the end of the short rainy season (September-November) and the short dry season (December-February). Physical, biological, and land cover data were integrated with entomological observations to collect Anopheles larvae in three major towns: Mitzic, Oyem, and Bitam, using the "dipping" method during the transition from rainy to dry season. The collected larvae were then reared in a field laboratory established for the study period. After the Anopheles mosquitoes had emerged, their species were identified using appropriate morphological taxonomic keys. To determine the influence of environmental factors on the breeding of Anopheles mosquitoes, multiple-factor analysis (MFA) and a binomial generalized linear model were used. RESULTS According to the study, only 33.1% out of the 284 larval habitats examined were found to be positive for Anopheles larvae, which were primarily identified as belonging to the Anopheles gambiae complex. The findings of the research suggested that the presence of An. gambiae complex larvae in larval habitats was associated with various significant factors such as higher urbanization, the size and type of the larval habitats (pools and puddles), co-occurrence with Culex and Aedes larvae, hot spots in ambient temperature, moderate rainfall, and land use patterns. CONCLUSIONS The results of this research mark the initiation of a focused vector control plan that aims to eradicate or lessen the larval habitats of An. gambiae mosquitoes in Gabon's Woleu Ntem province. This approach deals with the root causes of malaria transmission through larvae and is consistent with the World Health Organization's (WHO) worldwide objective to decrease malaria prevalence in regions where it is endemic.
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Affiliation(s)
- Neil-Michel Longo-Pendy
- Unité de Recherche en Ecologie de la Santé (URES), Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon.
| | - Silas Lendzele Sevidzem
- Laboratoire d'Ecologie des Maladies Transmissibles (LEMAT), Université Libreville Nord (ULN), Libreville, Gabon
| | | | - Saturnin Ndotit-Manguiengha
- Institut de Recherche en Écologie Tropicale (IRET), Libreville, Gabon
- Agence Gabonaise d'Etudes et d'Observations Spatiales (AGEOS), Libreville, Gabon
| | | | - Piazzy Obame Ondo Kutomy
- Programme National de Lutte Contre Le Paludisme (PNLP), Libreville, Gabon
- Universite Cheikh Anta Diop de Dakar (UCAD), Dakar, Sénégal
| | - Judicaël Obame-Nkoghe
- Unité de Recherche en Ecologie de la Santé (URES), Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon
- Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon
- Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of the Free State, Phuthaditjhaba, Republic of South Africa
| | - Lynda-Chancelya Nkoghe-Nkoghe
- Unité de Recherche en Ecologie de la Santé (URES), Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon
| | | | | | | | - Ayôla Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut Für Tropenmedizin, Eberhard Karls Universität, Tübingen, Germany
- Fondation Pour la Recherche Scientifique (FORS), P.O. Box 88, Cotonou, Benin
- German Center for Infection Research (DZIF), Partner site Tübingen, Tübingen, Germany
| | | | | | - Rodrigue Mintsa-Nguema
- Laboratoire d'Ecologie des Maladies Transmissibles (LEMAT), Université Libreville Nord (ULN), Libreville, Gabon
- Institut de Recherche en Écologie Tropicale (IRET), Libreville, Gabon
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3
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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.
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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
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Dennis TPW, Essandoh J, Mable BK, Viana MS, Yawson AE, Weetman D. Signatures of adaptation at key insecticide resistance loci in Anopheles gambiae in Southern Ghana revealed by reduced-coverage WGS. Sci Rep 2024; 14:8650. [PMID: 38622230 PMCID: PMC11018624 DOI: 10.1038/s41598-024-58906-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: 01/17/2024] [Accepted: 04/04/2024] [Indexed: 04/17/2024] Open
Abstract
Resistance to insecticides and adaptation to a diverse range of environments present challenges to Anopheles gambiae s.l. mosquito control efforts in sub-Saharan Africa. Whole-genome-sequencing is often employed for identifying the genomic basis underlying adaptation in Anopheles, but remains expensive for large-scale surveys. Reduced coverage whole-genome-sequencing can identify regions of the genome involved in adaptation at a lower cost, but is currently untested in Anopheles mosquitoes. Here, we use reduced coverage WGS to investigate population genetic structure and identify signatures of local adaptation in Anopheles mosquitoes across southern Ghana. In contrast to previous analyses, we find no structuring by ecoregion, with Anopheles coluzzii and Anopheles gambiae populations largely displaying the hallmarks of large, unstructured populations. However, we find signatures of selection at insecticide resistance loci that appear ubiquitous across ecoregions in An. coluzzii, and strongest in forest ecoregions in An. gambiae. Our study highlights resistance candidate genes in this region, and validates reduced coverage WGS, potentially to very low coverage levels, for population genomics and exploratory surveys for adaptation in Anopheles taxa.
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Affiliation(s)
- Tristan P W Dennis
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK.
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK.
| | - John Essandoh
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
- Department of Conservation Biology and Entomology, School of Biological Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Barbara K Mable
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Mafalda S Viana
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Alexander E Yawson
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Caputo B, De Marco CM, Pichler V, Bottà G, Bennett KL, Clarkson CS, Tennessen JA, Weetman D, Miles A, Torre AD. Speciation within the Anopheles gambiae complex: high-throughput whole genome sequencing reveals evidence of a putative new cryptic taxon in 'far-west' Africa. RESEARCH SQUARE 2024:rs.3.rs-3914444. [PMID: 38562903 PMCID: PMC10984024 DOI: 10.21203/rs.3.rs-3914444/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The two main Afrotropical malaria vectors - Anopheles coluzzii and An. gambiae - are genetically distinct and reproductively isolated across West Africa. However, populations at the western extreme of their range are assigned as "intermediate" between the two species by whole genome sequence (WGS) data, and as hybrid forms by conventional molecular diagnostics. By exploiting WGS data from 1,190 specimens collected across west Africa via the Anopheles gambiae 1000 Genomes network, we identify a novel putative taxon in the far-west (provisionally named Bissau molecular form), which did not arise by admixture but rather originated at the same time as the split between An. coluzzii and An. gambiae. Intriguingly, these populations lack insecticide resistance mechanisms commonly observed in the two main species. These findings lead to a change of perspective on malaria vector species in the far-west region with potential for epidemiological implications, and a new challenge for genetic-based mosquito control approaches.
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Affiliation(s)
- B Caputo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome Italy
| | - C M De Marco
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome Italy
| | - V Pichler
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome Italy
| | - G Bottà
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome Italy
| | - K L Bennett
- Wellcome Sanger Genomic Surveillance Unit, Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - C S Clarkson
- Wellcome Sanger Genomic Surveillance Unit, Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - J A Tennessen
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Broad Institute, Cambridge, MA, USA
| | - D Weetman
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - A Miles
- Wellcome Sanger Genomic Surveillance Unit, Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - A Della Torre
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome Italy
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Mbama Ntabi JD, Malda Bali ED, Lissom A, Akoton R, Djontu JC, Missontsa G, Mouzinga FH, Baina MT, Djogbenou L, Ndo C, Wondji C, Adegnika AA, Lenga A, Borrmann S, Ntoumi F. Contribution of Anopheles gambiae sensu lato mosquitoes to malaria transmission during the dry season in Djoumouna and Ntoula villages in the Republic of the Congo. Parasit Vectors 2024; 17:104. [PMID: 38431686 PMCID: PMC10908062 DOI: 10.1186/s13071-023-06102-7] [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: 04/01/2023] [Accepted: 12/17/2023] [Indexed: 03/05/2024] Open
Abstract
BACKGROUND Mosquitoes belonging to the Anopheles gambiae sensu lato complex play a major role in malaria transmission across Africa. This study assessed the relative importance of members of An. gambiae s.l. in malaria transmission in two rural villages in the Republic of the Congo. METHODS Adult mosquitoes were collected using electric aspirators from June to September 2022 in Djoumouna and Ntoula villages and were sorted by taxa based on their morphological features. Anopheles gambiae s.l. females were also molecularly identified. A TaqMan-based assay and a nested polymerase chain reaction (PCR) were performed to determine Plasmodium spp. in the mosquitoes. Entomological indexes were estimated, including man-biting rate, entomological inoculation rate (EIR), and diversity index. RESULTS Among 176 mosquitoes collected, An. gambiae s.l. was predominant (85.8%), followed by Culex spp. (13.6%) and Aedes spp. (0.6%). Three members of the An. gambiae s.l. complex were collected in both villages, namely An. gambiae sensu stricto (74.3%), Anopheles coluzzii (22.9%) and Anopheles arabiensis (2.8%). Three Plasmodium species were detected in An. gambiae s.s. and An. coluzzii (Plasmodium falciparum, P. malariae and P. ovale), while only P. falciparum and P. malariae were found in An. arabiensis. In general, the Plasmodium infection rate was 35.1% (53/151) using the TaqMan-based assay, and nested PCR confirmed 77.4% (41/53) of those infections. The nightly EIR of An. gambiae s.l. was 0.125 infectious bites per person per night (ib/p/n) in Djoumouna and 0.08 ib/p/n in Ntoula. The EIR of An. gambiae s.s. in Djoumouna (0.11 ib/p/n) and Ntoula (0.04 ib/p/n) was higher than that of An. coluzzii (0.01 and 0.03 ib/p/n) and An. arabiensis (0.005 and 0.0 ib/p/n). CONCLUSIONS This study provides baseline information on the dominant vectors and dynamics of malaria transmission in the rural areas of the Republic of the Congo during the dry season. In the two sampled villages, An. gambiae s.s. appears to play a predominant role in Plasmodium spp. TRANSMISSION
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Affiliation(s)
- Jacques Dollon Mbama Ntabi
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo.
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo.
| | - Espoir Divin Malda Bali
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Abel Lissom
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
- Department of Biological Sciences, Faculty of Science, University of Bamenda, Bamenda, Cameroon
| | - Romaric Akoton
- Fondation Pour La Recherche Scientifique (FORS), ISBA, BP: 88, Cotonou, Bénin
| | - Jean Claude Djontu
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
| | - Georges Missontsa
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
| | - Freisnel Hermeland Mouzinga
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Marcel Tapsou Baina
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Luc Djogbenou
- Tropical Infectious Diseases Research Center (TIDRC), University of Abomey-Calavi, Cotonou, Bénin
| | - Cyrille Ndo
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Department of Parasitology and Microbiology, Center for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
| | - Charles Wondji
- Department of Parasitology and Medical Entomology, Center for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Ayola Akim Adegnika
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Fondation Pour La Recherche Scientifique (FORS), ISBA, BP: 88, Cotonou, Bénin
- Centre de Recherche Médicale de Lambaréné, Lambaréné, Gabon
- German Center of Infection Research (DZIF), Tübingen, Germany
| | - Arsène Lenga
- Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Republic of the Congo
| | - Steffen Borrmann
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center of Infection Research (DZIF), Tübingen, Germany
| | - Francine Ntoumi
- Fondation Congolaise Pour La Recherche Médicale, Brazzaville, Republic of the Congo.
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
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Ashu FA, Fouet C, Ambadiang MM, Penlap-Beng V, Kamdem C. Adult mosquitoes of the sibling species Anopheles gambiae and Anopheles coluzzii exhibit contrasting patterns of susceptibility to four neonicotinoid insecticides along an urban-to-rural gradient in Yaoundé, Cameroon. Malar J 2024; 23:65. [PMID: 38431623 PMCID: PMC10909279 DOI: 10.1186/s12936-024-04876-4] [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: 09/13/2023] [Accepted: 02/10/2024] [Indexed: 03/05/2024] Open
Abstract
BACKGROUND Neonicotinoids are potential alternatives for controlling pyrethroid-resistant mosquitoes, but their efficacy against malaria vector populations of sub-Saharan Africa has yet to be investigated. The aim of the present study was to test the efficacy of four neonicotinoids against adult populations of the sibling species Anopheles gambiae and Anopheles coluzzii sampled along an urban-to-rural gradient. METHODS The lethal toxicity of three active ingredients for adults of two susceptible Anopheles strains was assessed using concentration-response assays, and their discriminating concentrations were calculated. The discriminating concentrations were then used to test the susceptibility of An. gambiae and An. coluzzii mosquitoes collected from urban, suburban and rural areas of Yaoundé, Cameroon, to acetamiprid, imidacloprid, clothianidin and thiamethoxam. RESULTS Lethal concentrations of neonicotinoids were relatively high suggesting that this class of insecticides has low toxicity against Anopheles mosquitoes. Reduced susceptibility to the four neonicotinoids tested was detected in An. gambiae populations collected from rural and suburban areas. By contrast, adults of An. coluzzii that occurred in urbanized settings were susceptible to neonicotinoids except acetamiprid for which 80% mortality was obtained within 72 h of insecticide exposure. The cytochrome inhibitor, piperonyl butoxide (PBO), significantly enhanced the activity of clothianidin and acetamiprid against An. gambiae mosquitoes. CONCLUSIONS These findings corroborate susceptibility profiles observed in larvae and highlight a significant variation in tolerance to neonicotinoids between An. gambiae and An. coluzzii populations from Yaoundé. Further studies are needed to disentangle the role of exposure to agricultural pesticides and of cross-resistance mechanisms in the development of neonicotinoid resistance in some Anopheles species.
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Affiliation(s)
- Fred A Ashu
- Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé 9, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 11 812, Yaoundé, Cameroon
| | - Caroline Fouet
- Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX, 79968, USA
| | - Marilene M Ambadiang
- Centre for Research in Infectious Diseases, P.O. Box 13591, Yaoundé 9, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 11 812, Yaoundé, Cameroon
| | - Véronique Penlap-Beng
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 11 812, Yaoundé, Cameroon
| | - Colince Kamdem
- Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX, 79968, USA.
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8
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Ambadiang M, Fouet C, Ashu F, Bouaka C, Penlap-Beng V, Kamdem C. Anopheles gambiae larvae's ability to grow and emerge in water containing lethal concentrations of clothianidin, acetamiprid, or imidacloprid is consistent with cross-resistance to neonicotinoids. Parasit Vectors 2024; 17:98. [PMID: 38429846 PMCID: PMC10905935 DOI: 10.1186/s13071-024-06188-7] [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: 08/29/2023] [Accepted: 02/08/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND For decades, various agrochemicals have been successfully repurposed for mosquito control. However, preexisting resistance caused in larval and adult populations by unintentional pesticide exposure or other cross-resistance mechanisms poses a challenge to the efficacy of this strategy. A better understanding of larval adaptation to the lethal and sublethal effects of residual pesticides in aquatic habitats would provide vital information for assessing the efficacy of repurposed agrochemicals against mosquitoes. METHODS We reared field-collected mosquito larvae in water containing a concentration of agrochemical causing 100% mortality in susceptible mosquitoes after 24 h (lethal concentration). Using this experimental setup, we tested the effect of lethal concentrations of a pyrrole (chlorfenapyr, 0.10 mg/l), a pyrethroid (deltamethrin, 1.5 mg/l), and three neonicotinoids including imidacloprid (0.075 mg/l), acetamiprid (0.15 mg/l), and clothianidin (0.035 mg/l) on mortality rates, growth, and survival in third-instar larvae of the two sibling species Anopheles gambiae and Anopheles coluzzii collected from Yaoundé, Cameroon. RESULTS We found that An. gambiae and An. coluzzii larvae were susceptible to chlorfenapyr and were killed within 24 h by a nominal concentration of 0.10 mg/l. Consistent with strong resistance, deltamethrin induced low mortality in both species. Lethal concentrations of acetamiprid, imidacloprid, and clothianidin strongly inhibited survival, growth, and emergence in An. coluzzii larvae. By contrast, depending on the active ingredient and the population tested, 5-60% of immature stages of An. gambiae were able to grow and emerge in water containing a lethal concentration of neonicotinoids, suggesting cross-resistance to this class of insecticides. CONCLUSIONS These findings corroborate susceptibility profiles observed in adults and suggest that unintentional pesticide exposure or other cross-resistance processes could contribute to the development of resistance to neonicotinoids in some Anopheles populations.
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Affiliation(s)
- Marilene Ambadiang
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Caroline Fouet
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, USA
| | - Fred Ashu
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Calmes Bouaka
- Centre for Research in Infectious Diseases (CRID), Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Véronique Penlap-Beng
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, Yaoundé, Cameroon
| | - Colince Kamdem
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, USA.
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9
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Ebhodaghe FI, Sanchez-Vargas I, Isaac C, Foy BD, Hemming-Schroeder E. Sibling species of the major malaria vector Anopheles gambiae display divergent preferences for aquatic breeding sites in southern Nigeria. Malar J 2024; 23:60. [PMID: 38413961 PMCID: PMC10900747 DOI: 10.1186/s12936-024-04871-9] [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: 10/23/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND When integrated with insecticide-treated bed nets, larval control of Anopheles mosquitoes could fast-track reductions in the incidence of human malaria. However, larval control interventions may deliver suboptimal outcomes where the preferred breeding places of mosquito vectors are not well known. This study investigated the breeding habitat choices of Anopheles mosquitoes in southern Nigeria. The objective was to identify priority sites for mosquito larval management in selected urban and periurban locations where malaria remains a public health burden. METHODS: Mosquito larvae were collected in urban and periurban water bodies during the wet-dry season interface in Edo, Delta, and Anambra States. Field-collected larvae were identified based on PCR gel-electrophoresis and amplicon sequencing, while the associations between Anopheles larvae and the properties and locations of water bodies were assessed using a range of statistical methods. RESULTS Mosquito breeding sites were either man-made (72.09%) or natural (27.91%) and mostly drainages (48.84%) and puddles (25.58%). Anopheles larvae occurred in drainages, puddles, stream margins, and a concrete well, and were absent in drums, buckets, car tires, and a water-holding iron pan, all of which contained culicine larvae. Wild-caught Anopheles larvae comprised Anopheles coluzzii (80.51%), Anopheles gambiae sensu stricto (s.s.) (11.54%), and Anopheles arabiensis (7.95%); a species-specific PCR confirmed the absence of the invasive urban malaria vector Anopheles stephensi among field-collected larvae. Anopheles arabiensis, An. coluzzii, and An. gambiae s.s. displayed preferences for turbid, lowland, and partially sunlit water bodies, respectively. Furthermore, An. arabiensis preferred breeding sites located outside 500 m of households, whereas An. gambiae s.s. and An. coluzzii had increased detection odds in sites within 500 m of households. Anopheles gambiae s.s. and An. coluzzii were also more likely to be present in natural water bodies; meanwhile, 96.77% of An. arabiensis were in man-made water bodies. Intraspecific genetic variations were little in the dominant vector An. coluzzii, while breeding habitat choices of populations made no statistically significant contributions to these variations. CONCLUSION Sibling malaria vectors in the An. gambiae complex display divergent preferences for aquatic breeding habitats in southern Nigeria. The findings are relevant for planning targeted larval control of An. coluzzii whose increasing evolutionary adaptations to urban ecologies are driving the proliferation of the mosquito, and An. arabiensis whose adults typically evade the effects of treated bed nets due to exophilic tendencies.
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Affiliation(s)
- Faith I Ebhodaghe
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Irma Sanchez-Vargas
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Clement Isaac
- Department of Zoology, Faculty of Life Sciences, Ambrose Alli University, Ekpoma, Edo State, Nigeria
| | - Brian D Foy
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Elizabeth Hemming-Schroeder
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
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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. RESEARCH SQUARE 2024:rs.3.rs-3953608. [PMID: 38410447 PMCID: PMC10896386 DOI: 10.21203/rs.3.rs-3953608/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
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. In the current study, we sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well asdescribe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzi 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 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. Results This study reports the detection of Anopheles coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points sampled and its presence confirmed through taxonomic analysis. Additionally, we found 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 of ~60%. 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 emphasise 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.
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Affiliation(s)
- Luna Kamau
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Kelly L Bennett
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Eric Ochomo
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Jeremy Herren
- International Centre of Insect Physiology and Ecology
| | - Silas Agumba
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Samson Otieno
- Centre for Global Health Research (CGHR), Kenya Medical Research Institute
| | - Diana Omoke
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research and Development (CBRD), Kenya Medical Research Institute
| | | | - Joseph Mwangangi
- Centre for Geographic Medicine Research-Coast (CGMR-C), Kenya Medical Research Institute
| | - Edith Ramaita
- Ministry of Health - National Malaria Control Programme (NMCP)
| | | | | | - Sonia Barasa
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
| | - Alistair Miles
- Malaria Vector Genomic Surveillance, Wellcome Trust Sanger Institute
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11
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Fouet C, Ashu FA, Ambadiang MM, Tchapga W, Wondji CS, Kamdem C. Clothianidin-resistant Anopheles gambiae adult mosquitoes from Yaoundé, Cameroon, display reduced susceptibility to SumiShield® 50WG, a neonicotinoid formulation for indoor residual spraying. BMC Infect Dis 2024; 24:133. [PMID: 38273227 PMCID: PMC10811947 DOI: 10.1186/s12879-024-09030-8] [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: 08/18/2023] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Chronic exposure of mosquito larvae to pesticide residues and cross-resistance mechanisms are major drivers of tolerance to insecticides used for vector control. This presents a concern for the efficacy of clothianidin, an agricultural neonicotinoid prequalified for Indoor Residual Spraying (IRS). METHODS Using standard bioassays, we tested if reduced susceptibility to clothianidin can affect the efficacy of SumiShield® 50WG, one of four new IRS formulations containing clothianidin. We simultaneously monitored susceptibility to clothianidin and to SumiShield 50WG, testing adults of Anopheles gambiae, An. coluzzii and Culex sp sampled from urban, suburban and agricultural areas of Yaoundé, Cameroon. RESULTS We found that in this geographic area, the level of susceptibility to the active ingredient predicted the efficacy of SumiShield 50WG. This formulation was very potent against populations that reached 100% mortality within 72 h of exposure to a discriminating concentration of clothianidin. By contrast, mortality leveled off at 75.4 ± 3.5% within 7 days of exposure to SumiShield 50WG in An. gambiae adults collected from a farm where the spraying of the two neonicotinoids acetamiprid and imidacloprid for crop protection is likely driving resistance to clothianidin. CONCLUSIONS Despite the relatively small geographic extend of the study, the findings suggest that cross-resistance may impact the efficacy of some new IRS formulations and that alternative compounds could be prioritized in areas where neonicotinoid resistance is emerging.
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Affiliation(s)
- Caroline Fouet
- Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave, El Paso, TX, 79968, USA
| | - Fred A Ashu
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Marilene M Ambadiang
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Williams Tchapga
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
| | - Charles S Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. Box 13591, Yaoundé, Cameroon
- Vector Biology Department, Liverpool School of Tropical Medicine (LSTM), Pembroke Place, Liverpool, L3 5QA, UK
| | - Colince Kamdem
- Department of Biological Sciences, The University of Texas at El Paso, 500 W. University Ave, El Paso, TX, 79968, USA.
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12
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Mwima R, Hui TYJ, Nanteza A, Burt A, Kayondo JK. Potential persistence mechanisms of the major Anopheles gambiae species complex malaria vectors in sub-Saharan Africa: a narrative review. Malar J 2023; 22:336. [PMID: 37936194 PMCID: PMC10631165 DOI: 10.1186/s12936-023-04775-0] [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: 03/22/2023] [Accepted: 10/30/2023] [Indexed: 11/09/2023] Open
Abstract
The source of malaria vector populations that re-establish at the beginning of the rainy season is still unclear yet knowledge of mosquito behaviour is required to effectively institute control measures. Alternative hypotheses like aestivation, local refugia, migration between neighbouring sites, and long-distance migration (LDM) are stipulated to support mosquito persistence. This work assessed the malaria vector persistence dynamics and examined various studies done on vector survival via these hypotheses; aestivation, local refugia, local or long-distance migration across sub-Saharan Africa, explored a range of methods used, ecological parameters and highlighted the knowledge trends and gaps. The results about a particular persistence mechanism that supports the re-establishment of Anopheles gambiae, Anopheles coluzzii or Anopheles arabiensis in sub-Saharan Africa were not conclusive given that each method used had its limitations. For example, the Mark-Release-Recapture (MRR) method whose challenge is a low recapture rate that affects its accuracy, and the use of time series analysis through field collections whose challenge is the uncertainty about whether not finding mosquitoes during the dry season is a weakness of the conventional sampling methods used or because of hidden shelters. This, therefore, calls for further investigations emphasizing the use of ecological experiments under controlled conditions in the laboratory or semi-field, and genetic approaches, as they are known to complement each other. This review, therefore, unveils and assesses the uncertainties that influence the different malaria vector persistence mechanisms and provides recommendations for future studies.
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Affiliation(s)
- Rita Mwima
- Department of Entomology, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Tin-Yu J Hui
- Silwood Park Campus, Department of Life Sciences, Imperial College London, Ascot, UK
| | - Ann Nanteza
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB), Makerere University, Kampala, Uganda
| | - Austin Burt
- Silwood Park Campus, Department of Life Sciences, Imperial College London, Ascot, UK
| | - Jonathan K Kayondo
- Department of Entomology, Uganda Virus Research Institute (UVRI), Entebbe, Uganda.
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Cuthbert RN, Darriet F, Chabrerie O, Lenoir J, Courchamp F, Claeys C, Robert V, Jourdain F, Ulmer R, Diagne C, Ayala D, Simard F, Morand S, Renault D. Invasive hematophagous arthropods and associated diseases in a changing world. Parasit Vectors 2023; 16:291. [PMID: 37592298 PMCID: PMC10436414 DOI: 10.1186/s13071-023-05887-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/18/2023] [Indexed: 08/19/2023] Open
Abstract
Biological invasions have increased significantly with the tremendous growth of international trade and transport. Hematophagous arthropods can be vectors of infectious and potentially lethal pathogens and parasites, thus constituting a growing threat to humans-especially when associated with biological invasions. Today, several major vector-borne diseases, currently described as emerging or re-emerging, are expanding in a world dominated by climate change, land-use change and intensive transportation of humans and goods. In this review, we retrace the historical trajectory of these invasions to better understand their ecological, physiological and genetic drivers and their impacts on ecosystems and human health. We also discuss arthropod management strategies to mitigate future risks by harnessing ecology, public health, economics and social-ethnological considerations. Trade and transport of goods and materials, including vertebrate introductions and worn tires, have historically been important introduction pathways for the most prominent invasive hematophagous arthropods, but sources and pathways are likely to diversify with future globalization. Burgeoning urbanization, climate change and the urban heat island effect are likely to interact to favor invasive hematophagous arthropods and the diseases they can vector. To mitigate future invasions of hematophagous arthropods and novel disease outbreaks, stronger preventative monitoring and transboundary surveillance measures are urgently required. Proactive approaches, such as the use of monitoring and increased engagement in citizen science, would reduce epidemiological and ecological risks and could save millions of lives and billions of dollars spent on arthropod control and disease management. Last, our capacities to manage invasive hematophagous arthropods in a sustainable way for worldwide ecosystems can be improved by promoting interactions among experts of the health sector, stakeholders in environmental issues and policymakers (e.g. the One Health approach) while considering wider social perceptions.
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Affiliation(s)
- Ross N Cuthbert
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK.
| | | | - Olivier Chabrerie
- UMR CNRS 7058 "Ecologie et Dynamique des Systèmes Anthropisés" (EDYSAN), Université de Picardie Jules Verne, 1 rue des Louvels, 80037, Amiens Cedex 1, France
| | - Jonathan Lenoir
- UMR CNRS 7058 "Ecologie et Dynamique des Systèmes Anthropisés" (EDYSAN), Université de Picardie Jules Verne, 1 rue des Louvels, 80037, Amiens Cedex 1, France
| | - Franck Courchamp
- Ecologie Systématique Evolution, Université Paris-Saclay, CNRS, AgroParisTech, Gif sur Yvette, France
| | - Cecilia Claeys
- Centre de Recherche sur les Sociétés et les Environnement Méditerranéens (CRESEM), UR 7397 UPVD, Université de Perpignan, Perpignan, France
| | - Vincent Robert
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
| | - Frédéric Jourdain
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
- Santé Publique France, Saint-Maurice, France
| | - Romain Ulmer
- UMR CNRS 7058 "Ecologie et Dynamique des Systèmes Anthropisés" (EDYSAN), Université de Picardie Jules Verne, 1 rue des Louvels, 80037, Amiens Cedex 1, France
| | - Christophe Diagne
- CBGP, Université Montpellier, CIRAD, INRAE, Institut Agro, IRD, 755 Avenue du Campus Agropolis, 34988, Cedex, Montferrier-Sur-Lez, France
| | - Diego Ayala
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
- Medical Entomology Unit, Institut Pasteur de Madagascar, BP 1274, Antananarivo, Madagascar
| | - Frédéric Simard
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
| | - Serge Morand
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
- Faculty of Veterinary Technology, CNRS - CIRAD, Kasetsart University, Bangkok, Thailand
| | - David Renault
- Université de Rennes, CNRS, ECOBIO (Ecosystèmes, Biodiversité, Évolution) - UMR 6553, Rennes, France
- Institut Universitaire de France, 1 Rue Descartes, Paris, France
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Suh Nchang A, Shinyuy LM, Noukimi SF, Njong S, Bambara S, Kalimba EM, Kamga J, Ghogomu SM, Frederich M, Talom JLL, Souopgui J, Robert A. Knowledge about Asymptomatic Malaria and Acceptability of Using Artemisia afra Tea among Health Care Workers (HCWs) in Yaoundé, Cameroon: A Cross-Sectional Survey. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6309. [PMID: 37444156 PMCID: PMC10341543 DOI: 10.3390/ijerph20136309] [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] [Received: 06/05/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023]
Abstract
Malaria is the most widespread endemic disease in Cameroon, and asymptomatic Plasmodium (gametocyte) carriers (APCs) constitute more than 95% of infectious human reservoirs in malaria endemic settings. This study assesses the knowledge of asymptomatic malaria (ASM) among health care workers (HCWs) in health facilities (HFs) in the Centre Region of Cameroon and the acceptability of using Artemisia afra tea to treat APCs. A cross-sectional descriptive survey was conducted among 100 HCWs, in four randomly selected HFs in the Centre Region, in the period of 1-20 April 2022, using semi-structured self-administered questionnaires. Logistic regression analyses were performed to determine factors associated with knowledge. More than seven in eight (88%) respondents were aware of the existence of ASM, 83% defined ASM correctly, 75% knew how it was diagnosed, 70% prescribe ACTs for APCs, and 51.1% were informed about ASM transmission. The professional category of HCWs was significantly associated with their knowledge of the existence and transmission of ASM, and longevity of service was associated with knowledge of transmission (p < 0.05). Two-thirds (67%) of respondents knew about Artemisia afra tea, 53.7% believed that it was effective in treating ASM, and 79% were willing to prescribe it if authorized. There was a fair level of knowledge of ASM among HCWs in the study settings.
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Affiliation(s)
- Abenwie Suh Nchang
- Department of Epidemiology and Biostatistics (EPID), Institute de Recherche Expérimentale et Clinique (IREC), Public Health School, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (S.N.); (S.B.); (A.R.)
| | - Lahngong Methodius Shinyuy
- Laboratory of Pharmacognosy, Department of Pharmacy, Center of Interdisciplinary Research on Medicine (CIRM), University of Liege, 4000 Liège, Belgium; (L.M.S.); (M.F.)
| | - Sandra Fankem Noukimi
- Embriology and Biotechnology Laboratory, IBMM-ULB, 6041 Gosselies, Belgium; (S.F.N.); (J.S.)
| | - Sylvia Njong
- Department of Epidemiology and Biostatistics (EPID), Institute de Recherche Expérimentale et Clinique (IREC), Public Health School, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (S.N.); (S.B.); (A.R.)
| | - Sylvie Bambara
- Department of Epidemiology and Biostatistics (EPID), Institute de Recherche Expérimentale et Clinique (IREC), Public Health School, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (S.N.); (S.B.); (A.R.)
| | | | - Joseph Kamga
- Biotechnology Unit, University of Buea, Buea P.O. Box 63, Cameroon; (J.K.); (S.M.G.)
| | | | - Michel Frederich
- Laboratory of Pharmacognosy, Department of Pharmacy, Center of Interdisciplinary Research on Medicine (CIRM), University of Liege, 4000 Liège, Belgium; (L.M.S.); (M.F.)
| | | | - Jacob Souopgui
- Embriology and Biotechnology Laboratory, IBMM-ULB, 6041 Gosselies, Belgium; (S.F.N.); (J.S.)
| | - Annie Robert
- Department of Epidemiology and Biostatistics (EPID), Institute de Recherche Expérimentale et Clinique (IREC), Public Health School, Université Catholique de Louvain (UCLouvain), 1200 Brussels, Belgium; (S.N.); (S.B.); (A.R.)
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15
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Fouet C, Ashu F, Ambadiang M, Tchapga W, Wondji C, Kamdem C. Resistance to clothianidin reduces the efficacy of SumiShield ® 50WG, a neonicotinoid formulation for indoor residual spraying, against Anopheles gambiae. RESEARCH SQUARE 2023:rs.3.rs-2847231. [PMID: 37162950 PMCID: PMC10168466 DOI: 10.21203/rs.3.rs-2847231/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chronic exposure of mosquito larvae to pesticide residues in agricultural areas is often associated with evolution of resistance to insecticides used for vector control. This presents a concern for the efficacy of clothianidin, an agricultural neonicotinoid qualified for Indoor Residual Spraying (IRS). Using standard bioassays, we tested if reduced susceptibility to clothianidin affects the efficacy of SumiShield® 50WG, one of the two newly approved formulations, which contains 50% clothianidin. We simultaneously monitored susceptibility to clothianidin and to SumiShield® 50WG, testing adults of Anopheles gambiae, An. coluzzii and Culex sp collected from urban, suburban and agricultural areas of Yaoundé. We found that the level of susceptibility to the active ingredient predicted the efficacy of SumiShield® 50WG. This formulation was very potent against populations that achieved 100% mortality within 72 h of exposure to a discriminating dose of clothianidin. By contrast, mortality leveled off at 75.4 ± 3.5% within 7 days of exposure to SumiShield® 50WG in An. gambiae adults collected from a farm where spraying of acetamiprid and imidacloprid is driving cross-resistance to clothianidin. These findings indicate that more potent formulations of clothianidin or different insecticides should be prioritized in areas where resistance is emerging.
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16
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Ambadiang MM, Fouet C, Ashu FA, Penlap-Beng V, Kamdem C. Chronic exposure of mosquito larvae to pesticide residues endangers a new generation of agrochemicals repurposed for malaria prevention. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.18.537423. [PMID: 37131679 PMCID: PMC10153215 DOI: 10.1101/2023.04.18.537423] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Agrochemicals have been successfully repurposed to control mosquitoes worldwide, but pesticides used in agriculture challenge their effectiveness by contaminating surface waters and driving insecticide resistance in larval populations. Here we implemented a new experimental approach to predict the efficacy of agricultural pesticides newly repurposed for malaria vector control. We mimicked insecticide resistance selection as it occurs in contaminated aquatic habitats by rearing field-collected mosquito larvae in water containing a dose of insecticide at which 100% of individuals from a susceptible strain died within 24 h. We then simultaneously monitored short-term lethal toxicity within 24 h and sublethal effects for 7 days. We found that due to chronic exposure to agricultural pesticides some mosquito populations are currently predisposed to rapidly adapt to neonicotinoids if they were used in vector control. Larvae collected from rural and agricultural areas where neonicotinoid formulations are intensively used for insect pest management were able to survive, grow, pupate and emerge in lethal doses of acetamiprid, imidacloprid and clothianidin. These results emphasize the importance of addressing prior exposure of larvae to formulations used in agriculture before applying agrochemicals against malaria vectors.
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Ashu FA, Fouet C, Ambadiang MM, Penlap-Beng V, Kamdem C. Enhancing the efficacy of neonicotinoids against mosquitoes and overcoming resistance issues. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.18.537427. [PMID: 37131663 PMCID: PMC10153211 DOI: 10.1101/2023.04.18.537427] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Background Neonicotinoids are potential alternatives for targeting pyrethroid-resistant mosquitoes, but their efficacy against malaria vector populations of Sub-Saharan Africa has yet to be investigated. Here we tested and compared the efficacy of four neonicotinoids alone or in combination with a synergist against two major vectors of Plasmodium . Results Using standard bioassays, we first assessed the lethal toxicity of three active ingredients against adults of two susceptible Anopheles strains and we determined discriminating doses for monitoring susceptibility in wild populations. We then tested the susceptibility of 5532 Anopheles mosquitoes collected from urban and rural areas of Yaoundé, Cameroon, to discriminating doses of acetamiprid, imidacloprid, clothianidin and thiamethoxam. We found that in comparison with some public health insecticides, neonicotinoids have high lethal concentration, LC 99 , reflecting their low toxicity to Anopheles mosquitoes. In addition to this reduced toxicity, resistance to the four neonicotinoids tested was detected in An. gambiae populations collected from agricultural areas where larvae are intensively exposed to crop-protection neonicotinoids. However, adults of another major vector that occurred in urbanized settings, An. coluzzii , were fully susceptible to neonicotinoids except acetamiprid for which 80% mortality was obtained within 72 h of insecticide exposure. Importantly, the cytochrome inhibitor, piperonyl butoxide (PBO), was very effective in enhancing the activity of clothianidin and acetamiprid providing opportunities to create potent neonicotinoid formulations against Anopheles . Conclusion These findings suggest that to successfully repurpose agricultural neonicotinoids for malaria vector control, it is essential to use formulations containing synergists such as PBO or surfactants to ensure optimal efficacy.
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Boerlijst SP, Johnston ES, Ummels A, Krol L, Boelee E, van Bodegom PM, Schrama MJJ. Biting the hand that feeds: Anthropogenic drivers interactively make mosquitoes thrive. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159716. [PMID: 36302419 DOI: 10.1016/j.scitotenv.2022.159716] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/02/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Anthropogenic stressors on the environment are increasing at unprecedented rates and include urbanization, nutrient pollution, water management, altered land use and climate change. Their effects on disease vectors are poorly understood. A series of full factorial experiments investigated how key human induced abiotic pressures, and interactions between these, affect population parameters of the cosmopolitan disease vector, Culex pipiens s.l. Selected pressures include eutrophication, salinity, mean temperature, and temperature fluctuation. Data were collected for each individual pressure and for potential interactions between eutrophication, salinization and temperature. All experiments assessed survival, time to pupation, time to emergence, sex-ratio and ovipositioning behavior. The results show that stressors affect vector survival, may speed up development and alter female to male ratio, although large differences between stressors exist to quite different extents. While positive effects of increasing levels of eutrophication on survival were consistent, negative effects of salinity on survival were only apparent at higher temperatures, thus indicating a strong interaction effect between salinization and temperature. Temperature had no independent effect on larval survival. Overall, increasing eutrophication and temperatures, and the fluctuations thereof, lowered development rate, time to pupation and time to emergence while increasing levels of salinity increased development time. Higher levels of eutrophication positively impacted egg-laying behavior; the reverse was found for salinity while no effects of temperature on egg-laying behavior were observed. Results suggest large and positive impacts of anthropogenically induced habitat alterations on mosquito population dynamics. Many of these effects are exacerbated by increasing temperatures and fluctuations therein. In a world where eutrophication and salinization are increasingly abundant, mosquitoes are likely important benefactors. Ultimately, this study illustrates the importance of including multiple and combined stressors in predictive models as well as in prevention and mitigation strategies, particularly because they resonate with possible, but yet underdeveloped action plans.
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Affiliation(s)
- S P Boerlijst
- Center for Environmental Research Leiden, Department of Environmental biology, University of Leiden, Einsteinweg 2, 2333CC Leiden, the Netherlands; Deltares, Daltonlaan 600, 3584 BK Utrecht, the Netherlands.
| | - E S Johnston
- University of Utrecht, Department Population Health Sciences, Yalelaan 7, 3584 CL Utrecht, the Netherlands
| | - A Ummels
- Center for Environmental Research Leiden, Department of Environmental biology, University of Leiden, Einsteinweg 2, 2333CC Leiden, the Netherlands
| | - L Krol
- Center for Environmental Research Leiden, Department of Environmental biology, University of Leiden, Einsteinweg 2, 2333CC Leiden, the Netherlands; Deltares, Daltonlaan 600, 3584 BK Utrecht, the Netherlands
| | - E Boelee
- Deltares, Daltonlaan 600, 3584 BK Utrecht, the Netherlands
| | - P M van Bodegom
- Center for Environmental Research Leiden, Department of Environmental biology, University of Leiden, Einsteinweg 2, 2333CC Leiden, the Netherlands
| | - M J J Schrama
- Center for Environmental Research Leiden, Department of Environmental biology, University of Leiden, Einsteinweg 2, 2333CC Leiden, the Netherlands
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Mazzucato M, Marchetti G, Barbujani M, Mulatti P, Fornasiero D, Casarotto C, Scolamacchia F, Manca G, Ferrè N. An integrated system for the management of environmental data to support veterinary epidemiology. Front Vet Sci 2023; 10:1069979. [PMID: 37026100 PMCID: PMC10070964 DOI: 10.3389/fvets.2023.1069979] [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: 10/14/2022] [Accepted: 02/28/2023] [Indexed: 04/08/2023] Open
Abstract
Environmental and climatic fluctuations can greatly influence the dynamics of infectious diseases of veterinary concern, or interfere with the implementation of relevant control measures. Including environmental and climatic aspects in epidemiological studies could provide policy makers with new insights to assign resources for measures to prevent or limit the spread of animal diseases, particularly those with zoonotic potential. The ever-increasing number of technologies and tools permits acquiring environmental data from various sources, including ground-based sensors and Satellite Earth Observation (SEO). However, the high heterogeneity of these datasets often requires at least some basic GIS (Geographic Information Systems) and/or coding skills to use them in further analysis. Therefore, the high availability of data does not always correspond to widespread use for research purposes. The development of an integrated data pre-processing system makes it possible to obtain information that could be easily and directly used in subsequent epidemiological analyses, supporting both research activities and the management of disease outbreaks. Indeed, such an approach allows for the reduction of the time spent on searching, downloading, processing and validating environmental data, thereby optimizing available resources and reducing any possible errors directly related to data collection. Although multitudes of free services that allow obtaining SEO data exist nowadays (either raw or pre-processed through a specific coding language), the availability and quality of information can be sub-optimal when dealing with very small scale and local data. In fact, some information sets (e.g., air temperature, rainfall), usually derived from ground-based sensors (e.g., agro-meteo station), are managed, processed and redistributed by agencies operating on a local scale which are often not directly accessible by the most common free SEO services (e.g., Google Earth Engine). The EVE (Environmental data for Veterinary Epidemiology) system has been developed to acquire, pre-process and archive a set of environmental information at various scales, in order to facilitate and speed up access by epidemiologists, researchers and decision-makers, also accounting for the integration of SEO information with locally sensed data.
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Fotso-Toguem Y, Tene-Fossog B, Mugenzi LMJ, Wondji MJ, Njiokou F, Ranson H, Wondji CS. Genetic Diversity of Cytochrome P450s CYP6M2 and CYP6P4 Associated with Pyrethroid Resistance in the Major Malaria Vectors Anopheles coluzzii and Anopheles gambiae from Yaoundé, Cameroon. Genes (Basel) 2022; 14:52. [PMID: 36672793 PMCID: PMC9858699 DOI: 10.3390/genes14010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Assessing the genetic diversity of metabolic resistance genes, such as cytochrome P450s, helps to understand the dynamics and evolution of resistance in the field. Here, we analyzed the polymorphisms of CYP6M2 and CYP6P4, associated with pyrethroid resistance in Anopheles coluzzii and Anopheles gambiae, to detect potential resistance markers. Field-caught resistant mosquitos and susceptible lab strains were crossed, and F4 was exposed to permethrin for 15 min and 90 min to discriminate highly susceptible (HS) and highly resistant (HR) mosquitos, respectively. Significant permethrin mortality reduction was observed after pre-exposure to PBO, suggesting the gene involvement of P450s. qPCR analysis revealed significant overexpression of CYP6M2 (FC = 19.57 [95% CI 13.96-25.18] for An. coluzzii; 10.16 [7.86-12.46] for An. gambiae) and CYP6P4 (FC = 6.73 [6.15-7.30] An. coluzzii; 23.62 [26.48-20.76] An. gambiae). Full-gene and ≈1 kb upstream were sequenced. For CYP6M2, the upstream region shows low diversity in HR and HS (overall Hd = 0.49, π = 0.018), whereas the full-gene shows allelic-variation but without evidence of ongoing selection. CYP6P4 upstream region showed a lower diversity in HR (Hd = 0.48) than HS (Hd = 0.86) of An. gambiae. These results highlighted that CYP6P4-associated resistance is potentially driven by modification in upstream region. However, further work is needed to determine the real causative variants that will help design rapid detection tools.
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Affiliation(s)
- Yvan Fotso-Toguem
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
| | - Billy Tene-Fossog
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
| | - Leon M. J. Mugenzi
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
| | - Murielle J. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
| | - Flobert Njiokou
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, Yaoundé P.O. Box 812, Cameroon
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
| | - Charles S. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35QA, UK
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Efa S, Elanga-Ndille E, Poumachu Y, Tene B, Mikande JZ, Zakariaou N, Wondji CS, Ndo C. Insecticide Resistance Profile and Mechanisms in An. gambiae s.l. from Ebolowa, South Cameroon. INSECTS 2022; 13:1133. [PMID: 36555042 PMCID: PMC9785700 DOI: 10.3390/insects13121133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/25/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Monitoring the trend of insecticide resistance and understanding associated genetic mechanisms is important for designing efficient malaria vector control strategies. This study was conducted to provide temporal data on insecticide resistance status and mechanisms in the major malaria vector Anopheles gambiae s.l. from Ebolowa, Southern Cameroon. Methods: Larvae of An. gambiae s.l. were collected from typical breeding sites throughout the city and reared to adulthood. Emerging adults were morphologically identified and WHO tube assays were performed to determine their susceptibility to carbamate, organophosphate and pyrethroid insecticides at diagnostic doses. When resistance was observed, its intensity was determined by performing WHO tube tests using 5 and 10 times the concentration of the diagnostic dose. Metabolic resistance mechanisms were investigated using insecticide-synergist assays. Sibling species of the An. gambiae complex were identified using SINE-PCR protocol. TaqMan assay was used to genotype the L1014F and L1014S kdr mutations, and the N1575Y mutation, an amplifier of the resistance conferred by the L1014F mutation. Results: Anopheles coluzzii was by far the dominant (99%) member of the An. gambiae s.l. complex in Ebolowa. The species was fully susceptible to carbamates and organophosphates, but resistant to all pyrethroid insecticides tested. Resistance was of moderate intensity for deltamethrin (mortality: 37%, 70% and 99% for 1×, 5× and 10× insecticide concentration, respectively) but rather of high intensity for permethrin (5% for 1×; 62% for 5× and 75% for 10×) and for alphacypermethrin (4.4% for 1×; 57% for 5× and 80% for 10×). Pre-exposure to the synergist PBO resulted in a full recovery of the susceptibility to delthametrin, but this was not observed for the other two pyrethroids tested. L1014S (kdr-East) and the N1575Y mutations were absent, whereas the L1014F (kdr-West) mutation was present at a high frequency (75%), showing a significant association with resistance to permethrin (OR = 3.8; 95%; CI [1.9−7.4]; p < 0.0001) and alphacypermethrin (OR = 3; 95%; CI [1.6−5.4]; p = 0.0002). Conclusion: The increased resistance of An. gambiae s.l. to pyrethroid insecticides as observed in Ebolowa poses a threat to the efficacy of LLINs used to protect populations from the bites of Anopheles mosquitoes that transmit malaria parasites. The present study further highlights the urgent need to implement resistance management strategies in order to maintain the effectiveness of insecticide-based vector control interventions and prevent a rebound in malaria-related mortality.
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Affiliation(s)
- Salomon Efa
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
- Faculty of Sciences, University of Yaoundé I, Yaoundé P.O. Box 337, Cameroon
| | - Emmanuel Elanga-Ndille
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
- Vector Borne Parasitic and Infectious Diseases Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Sciences, University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Yacouba Poumachu
- Vector Borne Parasitic and Infectious Diseases Unit of the Laboratory of Applied Biology and Ecology (VBID-LABEA), Department of Animal Biology, Faculty of Sciences, University of Dschang, Dschang P.O. Box 067, Cameroon
| | - Billy Tene
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
| | - Jacqueline Ze Mikande
- Department of Anesthesia and Reanimation, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé P.O Box 1364, Cameroon
| | - Njoumémi Zakariaou
- Department of Anesthesia and Reanimation, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé P.O Box 1364, Cameroon
| | - Charles S. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Cyrille Ndo
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaoundé P.O. Box 13591, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala P.O. Box 2701, Cameroon
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22
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Visa Shalini P, Shriram AN, Elango A, Natarajan R, Vijayakumar B, Raju KHK, Dengel L, Gunasekaran K, Kumar A. Mosquito Diversity in an Experimental Township in Tamil Nadu, India. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:1615-1624. [PMID: 35703108 PMCID: PMC9473653 DOI: 10.1093/jme/tjac064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Indexed: 06/15/2023]
Abstract
To glean more information on mosquito diversity and distribution in Auroville, a cross-sectional study was carried out by mapping the distribution of water bodies and habitats supporting immature stages on the one hand and the distribution of water bodies/habitats supporting mosquito immature stages on the other. A satellite image covering an area of 8.08 km2 was overlaid with a grid of 500 × 500 m. Fifteen modules were selected and the area of each module served as the sampling site for the entomological survey. Adult and larval stages were sampled. Diversity indices were analyzed to compare mosquito diversity. Rarefaction estimations were used to compare abundance and richness of the mosquito species between different zones. In total, 750 mosquito larvae and 84 resting adults were sampled. Eighteen species of mosquitoes belonging to 11 subgenera and 7 genera were documented. Genera included Aedes (Johann Wilhelm Meigen 1818, Diptera, Culicidae), Anopheles (Johann Wilhelm Meigen 1818, Diptera, Culicidae), Armigeres (Theobald 1901, Diptera, Culicidae), Culex (Carl Linnaeus 1758, Diptera, Culicidae), Lutzia (Theobald 1903, Diptera, Culicidae), and Mimomyia (Theobald 1903, Diptera, Culicidae). Of the 18 mosquito species identified, 8 species are new records for Auroville. The Alpha (α) biodiversity indices show that the mosquito fauna is diverse (S = 18; DMg = 2.732 [95% CI: 2.732-2.732]). The Shannon-Weiner (H' = 2.199 [95% CI: 2.133-2.276]) and Simpson indices (λ = 0.8619 [95% CI: 0.8496-0.8723]) measured species richness, evenness, and dominance. The values of these indices suggest high species richness, evenness, and dominance. Prevailing conditions can provide suitable environment for establishment of different mosquito species in this ecosystem. Given the sociodemographic characteristics of this area, research on mosquito diversity and risk of vector-borne diseases will be of great use.
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Affiliation(s)
- P Visa Shalini
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | | | - A Elango
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | - R Natarajan
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | - B Vijayakumar
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | - K H K Raju
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | - Lucas Dengel
- EcoPro, Aurosarjan Complex, Auroshilpam, Auroville, Tamil Nadu 605 101, India
| | - K Gunasekaran
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
| | - Ashwani Kumar
- ICMR-Vector Control Research Centre, Department of Health Research, Ministry of Health & Family Welfare, GOI, Medical Complex, Indira Nagar, Puducherry 605 006, India
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Tene‐Fossog B, Fotso‐Toguem YG, Amvongo‐Adjia N, Ranson H, Wondji CS. Temporal variation of high-level pyrethroid resistance in the major malaria vector Anopheles gambiae s.l. in Yaoundé, Cameroon, is mediated by target-site and metabolic resistance. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:247-259. [PMID: 35521949 PMCID: PMC9545389 DOI: 10.1111/mve.12577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/11/2022] [Indexed: 06/14/2023]
Abstract
Constant assessment of insecticide resistance levels is mandatory to implement adequate malaria control tools, but little information is available on the annual dynamics of resistance. We, therefore, monitored variations in resistance in Anopheles gambiae s.l. over four seasons during 2 years in two localities of Yaoundé: urban Etoa-Meki and peri-urban Nkolondom. Mosquitoes were collected seasonally at larval stage and reared to adults for insecticide susceptibility tests and molecular analysis of resistance mechanisms. Anopheles coluzzii was found in Etoa-Meki and An. gambiae in Nkolondom. Low mortalities to pyrethroids were observed (permethrin <10%, deltamethrin <21%), and resistance extended to 5× and 10× diagnostic doses, revealing a marked increase compared to previous studies. A seasonal variation in resistance was observed with the highest levels within dry seasons in Etoa-Meki and rainy seasons in Nkolondom. The 1014F kdr allele shows a high frequency (0.9), associated with overexpression of metabolic genes (Cyp6M2, Cyp6P4, Cyp9K1, Cyp6Z1, and Cyp6Z2) varying significantly seasonally. This study reveals an escalation in resistance to pyrethroids in Yaoundé's malaria vectors with seasonal variations. An adequate choice of the implementation period of punctual vector control actions according to the resistance profile will help to potentiate the desired effect and thus improve its efficiency.
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Affiliation(s)
- Billy Tene‐Fossog
- Department of Medical EntomologyCentre for Research in Infectious Diseases (CRID)YaoundéCameroon
| | - Yvan Gaetan Fotso‐Toguem
- Department of Medical EntomologyCentre for Research in Infectious Diseases (CRID)YaoundéCameroon
- Department of Animal Biology and Physiology, Faculty of ScienceUniversity of Yaoundé 1YaoundéCameroon
| | - Nathalie Amvongo‐Adjia
- Department of Medical EntomologyCentre for Research in Infectious Diseases (CRID)YaoundéCameroon
- Medical Research CentreInstitute of Medical Research and Medicinal Plants Studies (IMPM)YaoundéCameroon
| | - Hilary Ranson
- Department of Vector BiologyLiverpool School of Tropical MedicineLiverpoolUK
| | - Charles S. Wondji
- Department of Medical EntomologyCentre for Research in Infectious Diseases (CRID)YaoundéCameroon
- Department of Vector BiologyLiverpool School of Tropical MedicineLiverpoolUK
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Theodorou P. The effects of urbanisation on ecological interactions. CURRENT OPINION IN INSECT SCIENCE 2022; 52:100922. [PMID: 35490874 DOI: 10.1016/j.cois.2022.100922] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/10/2022] [Accepted: 04/10/2022] [Indexed: 05/25/2023]
Abstract
Cities are expanding worldwide and urbanisation is considered a global threat to biodiversity. Urban ecology has provided important insights on how urban environmental changes might affect individuals, populations, and species; however, we know little about how the ecological impacts of urbanisation alter species interactions. Species interactions are the backbone of ecological communities and play a crucial role in population and community dynamics and in the generation, maintenance and structure of biodiversity. Here, I review urban ecological studies to identify key mechanistic pathways through which urban environmental processes could alter antagonistic and mutualistic interactions among species. More specifically, I focus on insect predation, parasitoidism and herbivory, competition, insect host-pathogen interactions, and pollination. I furthermore identify important knowledge gaps that require additional research attention and I suggest future research directions that may help to shed light on the mechanisms that affect species interactions and structure insect communities and will thus aid conservation management in cities.
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Affiliation(s)
- Panagiotis Theodorou
- General Zoology, Institute for Biology, Martin-Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, 04103 Leipzig, Germany.
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25
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Huzortey AA, Kudom AA, Mensah BA, Sefa-Ntiri B, Anderson B, Akyea A. Water quality assessment in mosquito breeding habitats based on dissolved organic matter and chlorophyll measurements by laser-induced fluorescence spectroscopy. PLoS One 2022; 17:e0252248. [PMID: 35895685 PMCID: PMC9328511 DOI: 10.1371/journal.pone.0252248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/11/2022] [Indexed: 11/19/2022] Open
Abstract
Rapid urbanization and its associated pollution can affect water quality in mosquito breeding habitats and, as a result, the ecology and control of mosquito vectors. To understand the effects of pollution on mosquito vectors, an accurate assessment of water quality in breeding habitats is needed. Presently, water quality assessment of mosquito breeding habitats is usually based on the measurement of individual physicochemical parameters. However, several parameters are sometimes difficult to interpret or may not give a clear picture of the overall water quality of the breeding habitats, especially when the pollutants are in complex mixtures. This study employed the use of Laser-Induced Fluorescence (LIF) spectroscopy to assess water quality in breeding habitats of Anopheles, Aedes, and Culex mosquitoes in urban areas in Cape Coast, Ghana. The LIF spectra, using a 445-nm diode laser, were measured from field-collected water samples in the laboratory. The LIF spectra showed the presence of dissolved organic matter (DOM) and chlorophyll in the breeding habitats. The DOM and chlorophyll fluorescence signals were normalised by the Raman vibrational signals to determine water quality in each habitat. The overall water quality was better in Aedes breeding habitats than in Anopheles and Culex breeding habitats. The poor water quality in Anopheles and Culex breeding habitats was due to the presence of high fulvic acid and chlorophyll content, which often reflect pollutants from anthropogenic sources. Anopheles and Aedes habitats were made up of mainly An. coluzzii and Ae. aegypti respectively while Culex species were identified to genus level. The results add up to the growing concern about the breeding of Anopheles in polluted habitats. The study demonstrated for the first time the ability of LIF spectroscopy to assess water quality in mosquito breeding habitats.
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Affiliation(s)
- Andrew A. Huzortey
- Laser and Fibre Optics Centre, Department of Physics, University of Cape Coast, Cape Coast, Ghana
| | - Andreas A. Kudom
- Department of Conservation Biology and Entomology, University of Cape Coast, Cape Coast, Ghana
- * E-mail:
| | - Ben A. Mensah
- Department of Conservation Biology and Entomology, University of Cape Coast, Cape Coast, Ghana
| | - Baah Sefa-Ntiri
- Laser and Fibre Optics Centre, Department of Physics, University of Cape Coast, Cape Coast, Ghana
| | - Benjamin Anderson
- Laser and Fibre Optics Centre, Department of Physics, University of Cape Coast, Cape Coast, Ghana
| | - Angela Akyea
- Laser and Fibre Optics Centre, Department of Physics, University of Cape Coast, Cape Coast, Ghana
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Ngangue-Siewe IN, Ndjeunia-Mbiakop P, Kala-Chouakeu NA, Bamou R, Talipouo A, Djamouko-Djonkam L, Vontas J, Mavridis K, Tombi J, Tchuinkam T, Mbida-Mbida JA, Antonio-Nkondjio C. Bendiocarb and Malathion Resistance in Two Major Malaria Vector Populations in Cameroon Is Associated with High Frequency of the G119S Mutation (Ace-1) and Overexpression of Detoxification Genes. Pathogens 2022; 11:pathogens11080824. [PMID: 35894047 PMCID: PMC9330212 DOI: 10.3390/pathogens11080824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 12/10/2022] Open
Abstract
The spread of pyrethroid resistance in malaria vectors is a major threat affecting the performance of current control measures. However, there is still not enough information on the resistance profile of mosquitoes to carbamates and organophosphates which could be used as alternatives. The present study assessed the resistance profile of Anopheles gambiae s.l. to bendiocarb and malathion, at the phenotypic and molecular levels, in different eco-epidemiological settings in Cameroon. Anopheles gambiae s.l. mosquitoes were collected from four eco-epidemiological settings across the country and their susceptibility level to bendiocarb and malathion was determined using WHO tubes bioassays. The ace-1 target site G119S mutation was screened by PCR. Reverse Transcription quantitative PCR 3-plex TaqMan assays were used to quantify the level of expression of eight genes associated with metabolic resistance. Resistance to malathion and/or bendiocarb was recorded in all study sites except in mosquitoes collected in Kaélé and Njombé. The Ace-1 (G119S) mutation was detected in high frequencies (>40%) in Kékem and Santchou. Both An. gambiae and An. coluzzii were detected carrying this mutation. The cytochrome P450s gene Cyp6p3 associated with carbamate resistance and the glutathione S-transferase gene Gste2 associated with organophosphate resistance were found to be overexpressed. Genes associated with pyrethroid (Cyp6m2, Cyp9k1, Cyp6p3) and organochlorine (Gste2, Cyp6z1, Cyp6m2) and cuticle resistance (Cyp4g16) were also overexpressed. The rapid spread of resistance to organophosphates and carbamates could seriously compromise future control strategies based on IRS. It is therefore becoming important to assess the magnitude of bendiocarb and malathion resistance countrywide.
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Affiliation(s)
- Idriss Nasser Ngangue-Siewe
- Laboratory of Animal Biology and Physiology, University of Douala, Douala P.O. Box 24157, Cameroon; (I.N.N.-S.); (J.A.M.-M.)
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
| | - Paulette Ndjeunia-Mbiakop
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Faculty of Sciences, University of Yaoundé I, Yaoundé P.O. Box 812, Cameroon;
| | - Nelly Armanda Kala-Chouakeu
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon;
| | - Roland Bamou
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon;
| | - Abdou Talipouo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Faculty of Sciences, University of Yaoundé I, Yaoundé P.O. Box 812, Cameroon;
| | - Landre Djamouko-Djonkam
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon;
| | - John Vontas
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013 Heraklion, Greece; (J.V.); (K.M.)
- Pesticide Science Laboratory, Department of Crop Science, Agricultural University of Athens, 11855 Athens, Greece
| | - Konstantinos Mavridis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013 Heraklion, Greece; (J.V.); (K.M.)
| | - Jeannette Tombi
- Faculty of Sciences, University of Yaoundé I, Yaoundé P.O. Box 812, Cameroon;
| | - Timoléon Tchuinkam
- Vector-Borne Diseases Laboratory of the Applied Biology and Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang P.O. Box 067, Cameroon;
| | - Jean Arthur Mbida-Mbida
- Laboratory of Animal Biology and Physiology, University of Douala, Douala P.O. Box 24157, Cameroon; (I.N.N.-S.); (J.A.M.-M.)
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé P.O. Box 288, Cameroon; (P.N.-M.); (N.A.K.-C.); (R.B.); (A.T.); (L.D.-D.)
- Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Correspondence: ; Tel.: +237-699-53-86-56
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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.
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Perfect association between spatial swarm segregation and the X-chromosome speciation island in hybridizing Anopheles coluzzii and Anopheles gambiae populations. Sci Rep 2022; 12:10800. [PMID: 35750745 PMCID: PMC9232630 DOI: 10.1038/s41598-022-14865-9] [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: 03/08/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
The sibling species An. coluzzii and An. gambiae s.s. are major malaria vectors thought to be undergoing sympatric speciation with gene flow. In the absence of intrinsic post-zygotic isolation between the two taxa, speciation is thought possible through the association of assortative mating and genomic regions protected from gene flow by recombination suppression. Such genomic islands of speciation have been described in pericentromeric regions of the X, 2L and 3L chromosomes. Spatial swarm segregation plays a major role in assortative mating between sympatric populations of the two species and, given their importance for speciation, genes responsible for such pre-mating reproductive barriers are expected to be protected within divergence islands. In this study 2063 male and 266 female An. coluzzii and An. gambiae s.s. individuals from natural swarms in Burkina Faso, West Africa were sampled. These were genotyped at 16 speciation island SNPs, and characterized as non-hybrid individuals, F1 hybrids or recombinant F1+n backcrossed individuals. Their genotypes at each speciation island were associated with their participation in An. coluzzii and An. gambiae-like swarms. Despite extensive introgression between the two species, the X-island genotype of non-hybrid individuals (37.6%), F1 hybrids (0.1%) and F1+n recombinants (62.3%) of either sex perfectly associated to each swarm type. Associations between swarm type and the 3L and 2L speciation islands were weakened or broken down by introgression. The functional demonstration of a close association between spatial segregation behaviour and the X speciation island lends further support to sympatric speciation models facilitated by pericentric recombination suppression in this important species complex.
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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.
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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
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Systematic Review on Diversity and Distribution of Anopheles Species in Gabon: A Fresh Look at the Potential Malaria Vectors and Perspectives. Pathogens 2022; 11:pathogens11060668. [PMID: 35745522 PMCID: PMC9229970 DOI: 10.3390/pathogens11060668] [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: 04/15/2022] [Revised: 05/14/2022] [Accepted: 05/28/2022] [Indexed: 12/09/2022] Open
Abstract
Gabon is located in the malaria hyper-endemic zone, where data concerning malaria vector distribution remains fragmentary, making it difficult to implement an effective vector control strategy. Thus, it becomes crucial and urgent to undertake entomological surveys that will allow a better mapping of the Anopheles species present in Gabon. In this review, we examined different articles dealing with Anopheles in Gabon from ProQuest, Web of Science, PubMed, and Google scholar databases. After applying the eligibility criteria to 7543 articles collected from four databases, 42 studies were included that covered a 91-year period of study. The review revealed a wide diversity of Anopheles species in Gabon with a heterogeneous distribution. Indeed, our review revealed the presence of 41 Anopheles species, of which the most abundant were members of the Gambiae and Nili complexes and those of the Funestus and Moucheti groups. However, our review also revealed that the major and minor vectors of malaria in Gabon are present in both sylvatic, rural, and urban environments. The observation of human malaria vectors in sylvatic environments raises the question of the role that the sylvatic environment may play in maintaining malaria transmission in rural and urban areas. Ultimately, it appears that knowledge of biodiversity and spatial distribution of Anopheles mosquitoes is fragmentary in Gabon, suggesting that additional studies are necessary to complete and update these entomological data, which are useful for the implementation of vector control strategies.
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Fazeli-Dinan M, Azarnoosh M, Özgökçe MS, Chi H, Hosseini-Vasoukolaei N, Haghi FM, Zazouli MA, Nikookar SH, Dehbandi R, Enayati A, Zaim M, Hemingway J. Global water quality changes posing threat of increasing infectious diseases, a case study on malaria vector Anopheles stephensi coping with the water pollutants using age-stage, two-sex life table method. Malar J 2022; 21:178. [PMID: 35676692 PMCID: PMC9178840 DOI: 10.1186/s12936-022-04201-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 05/24/2022] [Indexed: 12/07/2022] Open
Abstract
Background Water pollution due to uncontrolled release of chemical pollutants is an important global problem. Its effect on medically important insects, especially mosquitoes, is a critical issue in the epidemiology of mosquito-borne diseases. Methods In order to understand the effect of water pollutants on the demography of Anopheles stephensi, colonies were reared in clean, moderately and highly polluted water for three consecutive generations at 27 °C, 75% RH, and a photoperiod of 12:12 h (L:D). The demographic data of the 4th generation of An. stephensi were collected and analysed using the age-stage, two-sex life table. Results The intrinsic rate of increase (r), finite rate of increase (λ), mean fecundity (F) and net reproductive rate (R0) of An. stephensi in clean water were 0.2568 d−1, 1.2927 d−1, 251.72 eggs, and 109.08 offspring, respectively. These values were significantly higher than those obtained in moderately polluted water (r = 0.2302 d−1, λ = 1.2589 d−1, 196.04 eggs, and R0 = 65.35 offspring) and highly polluted water (r = 0.2282 d−1, λ = 1.2564 d−1, 182.45 eggs, and R0 = 62.03 offspring). Female adult longevity in moderately polluted (9.38 days) and highly polluted water (9.88 days) were significantly shorter than those reared in clean water (12.43 days), while no significant difference in the male adult longevity was observed among treatments. Conclusions The results of this study showed that An. stephensi can partially adapt to water pollution and this may be sufficient to extend the range of mosquito-borne diseases.
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Affiliation(s)
- Mahmoud Fazeli-Dinan
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mostafa Azarnoosh
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mehmet Salih Özgökçe
- Faculty of Agriculture, Department of Plant Protection, Van Yuzuncu Yil University, 65080, Van, Turkey
| | - Hsin Chi
- Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Nasibeh Hosseini-Vasoukolaei
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Farzad Motevalli Haghi
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohamad Ali Zazouli
- Department of Environmental Health, Health Sciences Research Center, Addiction Institute, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Hassan Nikookar
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran
| | - Reza Dehbandi
- Environment Technologies Research Center, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran
| | - Ahmadali Enayati
- Department of Medical Entomology and Vector Control, Health Sciences Research Center, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Morteza Zaim
- Department of Medical Entomology and Vector Control, School of Public Health and National Institute of Health Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Janet Hemingway
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Sonhafouo-Chiana N, Nkahe LD, Kopya E, Awono-Ambene PH, Wanji S, Wondji CS, Antonio-Nkondjio C. Rapid evolution of insecticide resistance and patterns of pesticides usage in agriculture in the city of Yaoundé, Cameroon. Parasit Vectors 2022; 15:186. [PMID: 35655243 PMCID: PMC9164381 DOI: 10.1186/s13071-022-05321-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 05/11/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The practice of agriculture in urban settings contributes to the rapid expansion of insecticide resistance in malaria vectors. However, there is still not enough information on pesticide usage in most urban settings. The present study aims to assess the evolution of Anopheles gambiae (s.l.) population susceptibility to insecticides and patterns of pesticide usage in agriculture in the city of Yaoundé, Cameroon. METHODS WHO susceptibility tests and synergist PBO bioassays were conducted on adult An. gambiae (s.l.) mosquitoes aged 3 to 5 days emerging from larvae collected from the field. Seven insecticides (deltamethrin, permethrin, DDT, bendiocarb, propoxur, fenitrothion and malathion) were evaluated. The presence of target site mutation conferring knockdown (kdr) resistance was investigated using TaqMan assay, and mosquito species were identified using SINE-PCR. Surveys on 81 retailers and 232 farmers were conducted to assess general knowledge and practices regarding agricultural pesticide usage. RESULTS High resistance intensity to pyrethroids was observed with a high frequency of the kdr allele 1014F and low frequency of the kdr 1014S allele. The level of susceptibility of An. gambiae (s.l.) to pyrethroids and carbamates was found to decrease with time (from > 34% in 2017 to < 23% in 2019 for deltamethrin and permethrin and from 97% in 2017 to < 86% in 2019 for bendiocarb). Both An. gambiae (s.s.) and An. coluzzii were recorded. Over 150 pesticides and fertilizers were sold by retailers for agricultural purposes in the city of Yaoundé. Most farmers do not respect safety practices. Poor practices including extensive and inappropriate application of pesticides as well as poor management of perished pesticides and empty pesticide containers were also documented. CONCLUSIONS The study indicated rapid evolution of insecticide resistance and uncontrolled usage of pesticides by farmers in agriculture. There is an urgent need to address these gaps to improve the management of insecticide resistance.
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Affiliation(s)
- Nadège Sonhafouo-Chiana
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche de Yaoundé (IRY), P.O. Box 288, Yaoundé, Cameroon
- Parasites and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Leslie Diane Nkahe
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche de Yaoundé (IRY), P.O. Box 288, Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Edmond Kopya
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche de Yaoundé (IRY), P.O. Box 288, Yaoundé, Cameroon
- Faculty of Science, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - Parfait Herman Awono-Ambene
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche de Yaoundé (IRY), P.O. Box 288, Yaoundé, Cameroon
| | - Samuel Wanji
- Parasites and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, University of Buea, P.O. Box 63, Buea, Cameroon
- Research Foundation in Tropical Diseases and Environment (REFOTDE), P.O. Box 474, Buea, Cameroon
| | - Charles Sinclair Wondji
- Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Vector Biology, Liverpool School of Tropical medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Christophe Antonio-Nkondjio
- Organisation de Coordination pour la lutte Contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche de Yaoundé (IRY), P.O. Box 288, Yaoundé, Cameroon
- Vector Biology, Liverpool School of Tropical medicine, Pembroke Place, Liverpool, L3 5QA UK
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Faridah L, Fauziah N, Agustian D, Mindra Jaya IGN, Eka Putra R, Ekawardhani S, Hidayath N, Damar Djati I, Carvajal TM, Mayasari W, Ruluwedrata Rinawan F, Watanabe K. Temporal Correlation Between Urban Microclimate, Vector Mosquito Abundance, and Dengue Cases. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:1008-1018. [PMID: 35305089 PMCID: PMC9113159 DOI: 10.1093/jme/tjac005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Indexed: 05/04/2023]
Abstract
Dengue Hemorrhagic Fever (DHF) is a major mosquito-borne viral disease. Studies have reported a strong correlation between weather, the abundance of Aedes aegypti, the vector of DHF virus, and dengue incidence. However, this conclusion has been based on the general climate pattern of wide regions. In general, however, the human population, level of infrastructure, and land-use change in rural and urban areas often produce localized climate patterns that may influence the interaction between climate, vector abundance, and dengue incidence. Thoroughly understanding this correlation will allow the development of a customized and precise local early warning system. To achieve this purpose, we conducted a cohort study, during January-December 2017, in 16 districts in Bandung, West Java, Indonesia. In the selected areas, local weather stations and modified light mosquito traps were set up to obtain data regarding daily weather and the abundance of adult female Ae. aegypti. A generalized linear model was applied to analyze the effect of local weather and female adult Ae. aegypti on the number of dengue cases. The result showed a significant non-linear correlation among mosquito abundance, maximum temperature, and dengue cases. Using our model, the data showed that the addition of a single adult Ae. aegypti mosquito increased the risk of dengue infection by 1.8%, while increasing the maximum temperature by one degree decreased the risk by 17%. This finding suggests specific actionable insights needed to supplement existing mosquito eradication programs.
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Affiliation(s)
- Lia Faridah
- Parasitology Division, Department of Biomedical Sciences, Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
- Graduate School of Science and Engineering, Ehime University, Bunkyo-cho 3, Matsuyama, Ehime, 790-8577, Japan
- Corresponding author, e-mail: ;
| | - Nisa Fauziah
- Parasitology Division, Department of Biomedical Sciences, Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
| | - Dwi Agustian
- Department of Public Health Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
| | - I Gede Nyoman Mindra Jaya
- Department of Statistics Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
| | - Ramadhani Eka Putra
- School of Life Sciences and Technology, Insitut Teknologi Bandung, Jl. Ganeca 10, Bandung, 40132, West Java, Indonesia
- Biology Department, Insitut Teknologi Sumatera, Jl. Terusan Ryacudu, Desa Way Hui, Bandar Lampung, 35365, Lampung, Indonesia
| | - Savira Ekawardhani
- Parasitology Division, Department of Biomedical Sciences, Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
| | - Nurrachman Hidayath
- Dengue Study Group, Faculty of Medicine, Universitas Padjadjaran, Jl. Prof. Eyckman 38, Bandung, 40131, West Java, Indonesia
| | - Imam Damar Djati
- Faculty of Visual Art and Design, Industrial Design Section, Bandung Institute of Technology, Jl. Ganeca 10, Bandung, 40132, West Java, Indonesia
| | - Thaddeus M Carvajal
- Biological Control Research Unit, Center for Natural Science and Environmental Research-De La Salle University, Taft Ave Manila, Philippines
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 3, Matsuyama, Ehime, Japan
| | - Wulan Mayasari
- Anatomy Division, Department of Biomedical Science, Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang 45363, West Java, Indonesia
| | - Fedri Ruluwedrata Rinawan
- Department of Public Health Faculty of Medicine Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Sumedang, 45363, West Java, Indonesia
| | - Kozo Watanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 3, Matsuyama, Ehime, Japan
- Corresponding author, e-mail: ;
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Binyang AJ, Elanga-Ndille E, Tene-Fossog B, Ndo C, Nouage L, Assatse T, Fotso-Toguem Y, Tabue R, Zeukeng F, Nguiffo DN, Etang J, Njiokou F, Wondji CS. Distribution of acetylcholinesterase (Ace-1 R) target-site G119S mutation and resistance to carbamates and organophosphates in Anopheles gambiae sensu lato populations from Cameroon. Parasit Vectors 2022; 15:53. [PMID: 35164852 PMCID: PMC8842952 DOI: 10.1186/s13071-022-05174-1] [Citation(s) in RCA: 2] [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: 11/02/2021] [Accepted: 01/22/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Cameroon is considering the implementation of indoor residual spraying (IRS) as a complementary measure to control malaria in the context of high pyrethroid resistance in major malaria vectors. Non-pyrethroid insecticide classes such as organophosphates and carbamates may be utilized in IRS due to widespread pyrethroid resistance. However, the success of this strategy depends on good knowledge of the resistance status of malaria vectors to carbamates and organophosphates. Here, we assessed the susceptibility profile of Anopheles gambiae sensu lato with respect to carbamates and organophosphate and the distribution of the molecular mechanism underlying resistance to these insecticides. METHODS Anopheles gambiae s.l. mosquitoes were collected from nine settings across the country and bio-assayed with bendiocarb, propoxur and pirimiphos-methyl. The Ace-1 target-site G119S mutation was genotyped using a TaqMan assay. To investigate the polymorphism in the Ace-1 gene, a region of 924 base pairs in a sequence of the gene was amplified from both live and dead females of An. gambiae exposed to bendiocarb. RESULTS Pirimiphos-methyl induced full mortality in An. gambiae s.l. from all study sites, whereas for carbamates, resistance was observed in four localities, with the lowest mortality rate recorded in Mangoum (17.78 ± 5.02% for bendiocarb and 18.61 ± 3.86% for propoxur) in the southern part of Cameroon. Anopheles coluzzii was found to be the predominant species in the northern tropical part of the country where it is sympatric with Anopheles arabiensis. In the localities situated in southern equatorial regions, this species was predominant in urban settings, while An. gambiae was the most abundant species in rural areas. The G119S Ace-1 target-site mutation was detected only in An. gambiae and only in the sites located in southern Cameroon. Phylogenetic analyses showed a clustering according to the phenotype. CONCLUSION The occurrence of the Ace-1 target-site substitution G119S in An. gambiae s.l. populations highlights the challenge associated with the impending deployment of IRS in Cameroon using carbamates or organophosphates. It is therefore important to think about a resistance management plan including the use of other insecticide classes such as neonicotinoids or pyrrole to guarantee the implementation of IRS in Cameroon.
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Affiliation(s)
- Achille Jerome Binyang
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Emmanuel Elanga-Ndille
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- 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
| | - Billy Tene-Fossog
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
| | - Cyrille Ndo
- Department of Parasitology and Microbiology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Biological Science, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon
| | - Lynda Nouage
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Tatiane Assatse
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Yvan Fotso-Toguem
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Raymond Tabue
- Ministry of Public Health, National Malaria Control Programme, P.O. Box 14386, Yaoundé, Cameroon
| | - Francis Zeukeng
- National Reference Unit for Vector Control, The Biotechnology Centre, University of Yaoundé I, P.O. Box, 3851-Messa, Yaoundé, Cameroon
| | - Daniel Nguete Nguiffo
- Department of Parasitology and Microbiology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
| | - Josiane Etang
- Department of Biological Science, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon
- Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale, BP 288, Yaoundé, Cameroun
| | - Flobert Njiokou
- Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaoundé, Cameroon
| | - Charles S. Wondji
- Department of Medical Entomology, Centre for Research in Infectious Diseases (CRID), P.O. BOX 13591, Yaoundé, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
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Yokoly FN, Zahouli JBZ, Small G, Ouattara AF, Opoku M, de Souza DK, Koudou BG. Assessing Anopheles vector species diversity and transmission of malaria in four health districts along the borders of Côte d'Ivoire. Malar J 2021; 20:409. [PMID: 34663359 PMCID: PMC8524949 DOI: 10.1186/s12936-021-03938-1] [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: 09/12/2020] [Accepted: 10/01/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Although malaria and Anopheles mosquito vectors are highly prevalent in Côte d'Ivoire, limited data are available to help understand the malaria vector density and transmission dynamics in areas bordering the country. To address this gap, the Anopheles mosquito species diversity, the members of the Anopheles gambiae complex and the transmission of malaria were assessed in four health districts along the borders of Côte d'Ivoire. METHODS From July 2016 through December 2016 and July 2017 through December 2017, adult Anopheles mosquitoes were collected in four health districts of Côte d'Ivoire (Aboisso, Bloléquin, Odienné and Ouangolodougou) using standardized window exit trap (WET) and pyrethrum knockdown spray collection (PSC) methods. The collected mosquitoes were identified morphologically at species level and the members of the An. gambiae complex were separated using short interspersed nuclear element-based polymerase chain reaction (SINE-PCR). Anopheles gambiae sensu lato (s.l.), Anopheles funestus s.l. and Anopheles nili specimens were analysed for malaria Plasmodium parasite detection using the cytochrome oxidase I gene (COX-I), and malaria prevalence among human population through local Ministry of Health (MoH) statistical yearbooks. RESULTS A total of 281 female Anopheles were collected in Aboisso, 754 in Bloléquin, 1319 in Odienné and 2443 in Ouangolodougou. Seven Anopheles species were recorded including An. gambiae s.l. (94.8-99.1%) as the main vector, followed by An. funestus s.l. (0.4-4.3%) and An. nili (0-0.7%). Among An. gambiae s.l., Anopheles coluzzii represented the predominant species in Aboisso (89.2%) and Bloléquin (92.2%), while An. gambiae sensu stricto (s.s.) was the major species in Odienné (96.0%) and Ouangolodougou (94.2%). The Plasmodium sporozoite infection rate in An. gambiae s.l. was highest in Odienné (11.0%; n = 100) followed by Bloléquin (7.8%, n = 115), Aboisso (3.1%; n = 65) and Ouangologoudou (2.5%; n = 120). In An. funestus s.l., Plasmodium falciparum sporozoite infection rate was estimated at 6.2% (n = 32) in Bloléquin, 8.7% (n = 23) in Odienné. No An. funestus s.l. specimens were found infected with P. falciparum sporozoite infection in Ouangolodougou and Aboisso. No P. falciparum sporozoite was detected in An. nili specimens in the four health districts. Among the local human populations, malaria incidence was higher in Odienné (39.7%; n = 45,376) and Bloléquin (37.6%; n = 150,205) compared to that in Ouangolodougou (18.3%; n = 131,629) and Aboisso (19.7%; n = 364,585). CONCLUSION Anopheles vector species diversity, abundance and Plasmodium sporozoite infection were high within the health districts along the borders of the country of Côte d'Ivoire, resulting in high malaria transmission among the local populations. Anopheles gambiae s.l. and An. funestus s.l. were found to be highly infected with Plasmodium in the health districts of Bloléquin and Odienné where higher malaria incidence was observed than the other districts. This study provides important information that can be used to guide Côte d'Ivoire National Malaria Control Programme for vector control decision-making, mainly in districts that are at the country borders.
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Affiliation(s)
- Firmain N Yokoly
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d'Ivoire. .,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire.
| | - Julien B Z Zahouli
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire.,Centre d'Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d'Ivoire
| | - Graham Small
- Innovative Vector Control Consortium (IVCC), Pembroke Place, Liverpool, L3 5QA, UK
| | - Allassane F Ouattara
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d'Ivoire.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Millicent Opoku
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana.,European & Developing Countries Clinical Trials Partnership, Cape Town, South Africa
| | - Dziedzom K de Souza
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Benjamin G Koudou
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d'Ivoire.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
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Longo-Pendy NM, Tene-Fossog B, Tawedi RE, Akone-Ella O, Toty C, Rahola N, Braun JJ, Berthet N, Kengne P, Costantini C, Ayala D. Ecological plasticity to ions concentration determines genetic response and dominance of Anopheles coluzzii larvae in urban coastal habitats of Central Africa. Sci Rep 2021; 11:15781. [PMID: 34349141 PMCID: PMC8338965 DOI: 10.1038/s41598-021-94258-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 06/29/2021] [Indexed: 02/07/2023] Open
Abstract
In Central Africa, the malaria vector Anopheles coluzzii is predominant in urban and coastal habitats. However, little is known about the environmental factors that may be involved in this process. Here, we performed an analysis of 28 physicochemical characteristics of 59 breeding sites across 5 urban and rural sites in coastal areas of Central Africa. We then modelled the relative frequency of An. coluzzii larvae to these physicochemical parameters in order to investigate environmental patterns. Then, we assessed the expression variation of 10 candidate genes in An. coluzzii, previously incriminated with insecticide resistance and osmoregulation in urban settings. Our results confirmed the ecological plasticity of An. coluzzii larvae to breed in a large range of aquatic conditions and its predominance in breeding sites rich in ions. Gene expression patterns were comparable between urban and rural habitats, suggesting a broad response to ions concentrations of whatever origin. Altogether, An. coluzzii exhibits a plastic response to occupy both coastal and urban habitats. This entails important consequences for malaria control in the context of the rapid urban expansion in Africa in the coming years.
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Affiliation(s)
| | | | - Robert E. Tawedi
- grid.473396.cInstitut de Recherches Géologiques Et Minières / Centre de Recherches Hydrologiques, Yaoundé, Cameroon
| | | | - Celine Toty
- grid.462603.50000 0004 0382 3424MIVEGEC, Univ Montpellier, CNRS, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier, France
| | - Nil Rahola
- grid.462603.50000 0004 0382 3424MIVEGEC, Univ Montpellier, CNRS, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier, France
| | - Jean-Jacques Braun
- grid.473396.cInstitut de Recherches Géologiques Et Minières / Centre de Recherches Hydrologiques, Yaoundé, Cameroon ,grid.462928.30000 0000 9033 1612Géosciences Environnement Toulouse, Université de Toulouse, CNRS, IRD, Toulouse, France ,International Joint Laboratory DYCOFAC, IRGM-UY1-IRD, BP 1857, Yaoundé, Cameroon
| | - Nicolas Berthet
- grid.418115.80000 0004 1808 058XCIRMF, Franceville, Gabon ,grid.428999.70000 0001 2353 6535Institut Pasteur, Unité Environnement Et Risque Infectieux, Cellule D’Intervention Biologique D’Urgence, Paris, France
| | - Pierre Kengne
- grid.418115.80000 0004 1808 058XCIRMF, Franceville, Gabon ,grid.462603.50000 0004 0382 3424MIVEGEC, Univ Montpellier, CNRS, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier, France
| | - Carlo Costantini
- grid.462603.50000 0004 0382 3424MIVEGEC, Univ Montpellier, CNRS, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier, France
| | - Diego Ayala
- grid.418115.80000 0004 1808 058XCIRMF, Franceville, Gabon ,grid.462603.50000 0004 0382 3424MIVEGEC, Univ Montpellier, CNRS, IRD, 911 avenue Agropolis, BP 64501, 34394 Montpellier, France
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The origin of island populations of the African malaria mosquito, Anopheles coluzzii. Commun Biol 2021; 4:630. [PMID: 34040154 PMCID: PMC8155153 DOI: 10.1038/s42003-021-02168-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/21/2021] [Indexed: 11/09/2022] Open
Abstract
Anopheles coluzzii is a major malaria vector throughout its distribution in west-central Africa. Here we present a whole-genome study of 142 specimens from nine countries in continental Africa and three islands in the Gulf of Guinea. This sample set covers a large part of this species' geographic range. Our population genomic analyses included a description of the structure of mainland populations, island populations, and connectivity between them. Three genetic clusters are identified among mainland populations and genetic distances (FST) fits an isolation-by-distance model. Genomic analyses are applied to estimate the demographic history and ancestry for each island. Taken together with the unique biogeography and history of human occupation for each island, they present a coherent explanation underlying levels of genetic isolation between mainland and island populations. We discuss the relationship of our findings to the suitability of São Tomé and Príncipe islands as candidate sites for potential field trials of genetic-based malaria control strategies.
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Feufack-Donfack LB, Sarah-Matio EM, Abate LM, Bouopda Tuedom AG, Ngano Bayibéki A, Maffo Ngou C, Toto JC, Sandeu MM, Eboumbou Moukoko CE, Ayong L, Awono-Ambene P, Morlais I, Nsango SE. Epidemiological and entomological studies of malaria transmission in Tibati, Adamawa region of Cameroon 6 years following the introduction of long-lasting insecticide nets. Parasit Vectors 2021; 14:247. [PMID: 33964974 PMCID: PMC8106832 DOI: 10.1186/s13071-021-04745-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/23/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Malaria remains a serious public health problem in Cameroon. Implementation of control interventions requires prior knowledge of the local epidemiological situation. Here we report the results of epidemiological and entomological surveys carried out in Tibati, Adamawa Region, Cameroon, an area where malaria transmission is seasonal, 6 years after the introduction of long-lasting insecticidal bed nets. METHODS Cross-sectional studies were carried out in July 2015 and 2017 in Tibati. Thick blood smears and dried blood spots were collected from asymptomatic and symptomatic individuals in the community and at health centers, respectively, and used for the molecular diagnosis of Plasmodium species. Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly. The infection status of Plasmodium spp. was determined by quantitative PCR, and positivity of PCR-positive samples was confirmed by Sanger sequencing. RESULTS Overall malaria prevalence in our study population was 55.0% (752/1367) and Plasmodium falciparum was the most prevalent parasite species (94.3%), followed by P. malariae (17.7%) and P. ovale (0.8%); 92 (12.7%) infections were mixed infections. Infection parameters varied according to clinical status (symptomatic/asymptomatic) and age of the sampled population and the collection sites. Infection prevalence was higher in asymptomatic carriers (60.8%), but asexual and sexual parasite densities were lower. Prevalence and intensity of infection decreased with age in both the symptomatic and asymptomatic groups. Heterogeneity in infections was observed at the neighborhood level, revealing hotspots of transmission. Among the 592 Anopheles mosquitoes collected, 212 (35.8%) were An. gambiae, 172 (29.1%) were An. coluzzii and 208 (35.1%) were An. funestus (s.s.). A total of 26 (4.39%) mosquito specimens were infected by Plasmodium sp. and the three Anopheles mosquitoes transmitted Plasmodium at equal efficiency. Surprisingly, we found an An. coluzzii specimen infected by Plasmodium vivax, which confirms circulation of this species in Cameroon. The positivity of all 26 PCR-positive Plasmodium-infected mosquitoes was successively confirmed by sequencing analysis. CONCLUSION Our study presents the baseline malaria parasite burden in Tibati, Adamawa Region, Cameroon. Our results highlight the high malaria endemicity in the area, and hotspots of disease transmission are identified. Parasitological indices suggest low bednet usage and that implementation of control interventions in the area is needed to reduce malaria burden. We also report for the first time a mosquito vector with naturally acquired P. vivax infection in Cameroon.
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Affiliation(s)
- Lionel Brice Feufack-Donfack
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- CNRS UPR 9022, Inserm U 963, Université de Strasbourg, 2, allée Konrad Roentgen, 67084 Strasbourg Cedex, France
| | - Elangwe Milo Sarah-Matio
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Luc Marcel Abate
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Aline Gaelle Bouopda Tuedom
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
| | - Albert Ngano Bayibéki
- Université Catholique d’Afrique Centrale, Yaoundé-Campus Messa, BP 1110, Yaounde, Cameroon
| | - Christelle Maffo Ngou
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Jean-Claude Toto
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Maurice Marcel Sandeu
- Department of Medical Entomology, Centre for Research in Infectious Diseases, Yaounde, 13591 Cameroon
- Department of Microbiology and Infectious Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon
| | - Carole Else Eboumbou Moukoko
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
| | - Lawrence Ayong
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon
| | - Isabelle Morlais
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394 Montpellier, France
| | - Sandrine Eveline Nsango
- Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon
- Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701 Douala, Cameroon
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Caputo B, Pichler V, Bottà G, De Marco C, Hubbart C, Perugini E, Pinto J, Rockett KA, Miles A, Della Torre A. Novel genotyping approaches to easily detect genomic admixture between the major Afrotropical malaria vector species, Anopheles coluzzii and An. gambiae. Mol Ecol Resour 2021; 21:1504-1516. [PMID: 33590707 PMCID: PMC8252489 DOI: 10.1111/1755-0998.13359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 02/05/2021] [Accepted: 02/11/2021] [Indexed: 11/28/2022]
Abstract
The two most efficient and most recently radiated Afrotropical vectors of human malaria - Anopheles coluzzii and An. gambiae - are identified by single-locus diagnostic PCR assays based on species-specific markers in a 4 Mb region on chromosome-X centromere. Inherently, these diagnostic assays cannot detect interspecific autosomal admixture shown to be extensive at the westernmost and easternmost extremes of the species range. The main aim of this study was to develop novel, easy-to-implement tools for genotyping An. coluzzii and An. gambiae-specific ancestral informative markers (AIMs) identified from the Anopheles gambiae 1000 genomes (Ag1000G) project. First, we took advantage of this large set of data in order to develop a multilocus approach to genotype 26 AIMs on all chromosome arms valid across the species range. Second, we tested the multilocus assay on samples from Guinea Bissau, The Gambia and Senegal, three countries spanning the westernmost hybridization zone, where conventional species diagnostic is problematic due to the putative presence of a novel "hybrid form". The multilocus assay was able to capture patterns of admixture reflecting those revealed by the whole set of AIMs and provided new original data on interspecific admixture in the region. Third, we developed an easy-to-use, cost-effective PCR approach for genotyping two AIMs on chromosome-3 among those included in the multilocus approach, opening the possibility for advanced identification of species and of admixed specimens during routine large scale entomological surveys, particularly, but not exclusively, at the extremes of the range, where WGS data highlighted unexpected autosomal admixture.
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Affiliation(s)
- Beniamino Caputo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy
| | - Verena Pichler
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy
| | - Giordano Bottà
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy.,Wellcome Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - Carlo De Marco
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy
| | - Christina Hubbart
- Wellcome Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - Eleonora Perugini
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy
| | - Joao Pinto
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Kirk A Rockett
- Wellcome Centre for Human Genetics, University of Oxford, Headington, Oxford, UK
| | - Alistair Miles
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK.,MRC Centre for Genomics and Global Health, University of Oxford, Oxford, UK
| | - Alessandra Della Torre
- Dipartimento di Sanità Pubblica e Malattie Infettive, Istituto Pasteur Italia-Fondazione Cenci-Bolognetti, Università di Roma "Sapienza", Rome, Italy
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Akpodiete NO, Tripet F. Laboratory and microcosm experiments reveal contrasted adaptive responses to ammonia and water mineralisation in aquatic stages of the sibling species Anopheles gambiae (sensu stricto) and Anopheles coluzzii. Parasit Vectors 2021; 14:17. [PMID: 33407790 PMCID: PMC7789177 DOI: 10.1186/s13071-020-04483-7] [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: 07/29/2020] [Accepted: 11/12/2020] [Indexed: 11/10/2022] Open
Abstract
Background The sibling species of the malaria mosquito, Anopheles gambiae (sensu stricto) and Anopheles coluzzii co-exist in many parts of West Africa and are thought to have recently diverged through a process of ecological speciation with gene flow. Divergent larval ecological adaptations, resulting in Genotype-by-Environment (G × E) interactions, have been proposed as important drivers of speciation in these species. In West Africa, An. coluzzii tends to be associated with permanent man-made larval habitats such as irrigated rice fields, which are typically more eutrophic and mineral and ammonia-rich than the temporary rain pools exploited by An. gambiae (s.s.) Methods To highlight G × E interactions at the larval stage and their possible role in ecological speciation of these species, we first investigated the effect of exposure to ammonium hydroxide and water mineralisation on larval developmental success. Mosquito larvae were exposed to two water sources and increasing ammonia concentrations in small containers until adult emergence. In a second experiment, larval developmental success was compared across two contrasted microcosms to highlight G × E interactions under conditions such as those found in the natural environment. Results The first experiment revealed significant G × E interactions in developmental success and phenotypic quality for both species in response to increasing ammonia concentrations and water mineralisation. The An. coluzzii strain outperformed the An. gambiae (s.s.) strain under limited conditions that were closer to more eutrophic habitats. The second experiment revealed divergent crisscrossing reaction norms in the developmental success of the sibling species in the two contrasted larval environments. As expected, An. coluzzii had higher emergence rates in the rice paddy environment with emerging adults of superior phenotypic quality compared to An. gambiae (s.s.), and vice versa, in the rain puddle environment. Conclusions Evidence for such G × E interactions lends support to the hypothesis that divergent larval adaptations to the environmental conditions found in man-made habitats such as rice fields in An. coluzzii may have been an important driver of its ecological speciation. ![]()
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Affiliation(s)
- Nwamaka Oluchukwu Akpodiete
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK
| | - Frédéric Tripet
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Staffordshire, UK.
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Adaptive Evolution in Cities: Progress and Misconceptions. Trends Ecol Evol 2020; 36:239-257. [PMID: 33342595 DOI: 10.1016/j.tree.2020.11.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/01/2020] [Accepted: 11/09/2020] [Indexed: 12/14/2022]
Abstract
Current narratives suggest that urban adaptation - the adaptive evolution of organisms to cities - is pervasive across taxa and cities. However, in reviewing hundreds of studies, we find only six comprehensive examples of species adaptively evolving to urbanization. We discuss the utility and shortcomings of methods for studying urban adaptation. We then review diverse systems offering preliminary evidence for urban adaptation and outline a research program for advancing its study. Urban environments constitute diverse, interacting selective agents that test the limits of adaptation. Understanding urban adaptation therefore offers unique opportunities for addressing fundamental questions in evolutionary biology and for better conserving biodiversity in cities. However, capitalizing on these opportunities requires appropriate research methods and dissemination of accurate narratives.
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Yang PL, Nelson-Hurwitz DC, Katz AR. Evaluating Potential Mosquito Breeding Sites on a University Campus. HAWAI'I JOURNAL OF HEALTH & SOCIAL WELFARE 2020; 79:347-352. [PMID: 33313516 PMCID: PMC7726621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In recent decades, mosquito-borne diseases (MBDs) such as Zika, chikungunya, malaria, and dengue have spread to more urban areas previously free of such diseases. Globalization has increased the infection potential for diseases and their vectors, placing tropical tourist destinations, such as Hawai'i, at risk for MBD epidemics. A cross-sectional study was conducted on the University of Hawai'i at Mānoa campus to assess potential mosquito breeding sites. The campus was stratified by land use designation and randomly sampled. Residential areas had the highest potential for breeding sites with high numbers of discarded plastic food and beverage containers. Recommended prevention strategies to curb littering in the residential area include awareness campaigns and encouraging collaboration between maintenance authorities to enhance oversight. This study highlights the importance of individual awareness and prevention of environment modifications that could contribute to the development of mosquito breeding sites.
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Affiliation(s)
- Pua Lani Yang
- Office of Public Health Studies, University of Hawai‘i at Mānoa, 1960 East-West Road, Honolulu, HI
| | - Denise C. Nelson-Hurwitz
- Office of Public Health Studies, University of Hawai‘i at Mānoa, 1960 East-West Road, Honolulu, HI
| | - Alan R. Katz
- Office of Public Health Studies, University of Hawai‘i at Mānoa, 1960 East-West Road, Honolulu, HI
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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: 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: 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.
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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
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Nkemngo FN, Mugenzi LMJ, Terence E, Niang A, Wondji MJ, Tchoupo M, Nguete ND, Tchapga W, Irving H, Ntabi JDM, Agonhossou R, Boussougou-Sambe TS, Akoton RB, Koukouikila-Koussounda F, Pinilla YT, Ntoumi F, Djogbenou LS, Ghogomu SM, Ndo C, Adegnika AA, Borrmann S, Wondji CS. Multiple insecticide resistance and Plasmodium infection in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon. Wellcome Open Res 2020; 5:146. [PMID: 33204845 PMCID: PMC7667521 DOI: 10.12688/wellcomeopenres.15818.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms. Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a locality situated 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adults. Bioassays were performed to assess resistance profile to the four insecticides classes. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated. Results: Anopheles funestus s.s. was the most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having similar sporozoite rate. Both species exhibited high levels of resistance to the pyrethroids, permethrin and deltamethrin (<40% mortality). An. gambiae s.s. was resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively . Furthermore, the high pyrethroid/DDT resistances in An. gambiae corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b. Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the significant Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.
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Affiliation(s)
- Francis N. Nkemngo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, South West, 237, Cameroon
| | - Leon M. J. Mugenzi
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Ebai Terence
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Abdoulaye Niang
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Murielle J. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Micareme Tchoupo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Nguiffo D. Nguete
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Williams Tchapga
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jacques D. M. Ntabi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Romuald Agonhossou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Terence S. Boussougou-Sambe
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Romaric B. Akoton
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Felix Koukouikila-Koussounda
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Yudi T. Pinilla
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Luc S. Djogbenou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Stephen M. Ghogomu
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Cyrille Ndo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Ayola A. Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- Eberhard Karls Universität Tübingen,, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Charles S. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Mordecai EA, Ryan SJ, Caldwell JM, Shah MM, LaBeaud AD. Climate change could shift disease burden from malaria to arboviruses in Africa. Lancet Planet Health 2020; 4:e416-e423. [PMID: 32918887 PMCID: PMC7490804 DOI: 10.1016/s2542-5196(20)30178-9] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 05/28/2023]
Abstract
Malaria is a long-standing public health problem in sub-Saharan Africa, whereas arthropod-borne viruses (arboviruses) such as dengue and chikungunya cause an under-recognised burden of disease. Many human and environmental drivers affect the dynamics of vector-borne diseases. In this Personal View, we argue that the direct effects of warming temperatures are likely to promote greater environmental suitability for dengue and other arbovirus transmission by Aedes aegypti and reduce suitability for malaria transmission by Anopheles gambiae. Environmentally driven changes in disease dynamics will be complex and multifaceted, but given that current public efforts are targeted to malaria control, we highlight Ae aegypti and dengue, chikungunya, and other arboviruses as potential emerging public health threats in sub-Saharan Africa.
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Affiliation(s)
- Erin A. Mordecai
- Biology Department, Stanford University, 371 Serra Mall, Stanford, CA, United States
| | - Sadie J. Ryan
- Department of Geography, University of Florida, Gainesville, FL, United States; Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States; School of Life Sciences, College of Agriculture, Engineering, and Science, University of KwaZulu Natal, KwaZulu Natal, South Africa
| | - Jamie M. Caldwell
- Biology Department, Stanford University, 371 Serra Mall, Stanford, CA, United States
| | - Melisa M. Shah
- Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, United States
| | - A. Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Disease, School of Medicine, Stanford University, Stanford, CA, United States
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Elanga-Ndille E, Binyang A, Ndo C, Assatse T, Nouage L, Tchouakui M, Tene-Fossog B, Kekeunou S, Wondji CS. Entomological indicators of malaria transmission and insecticide resistance profile of Anopheles gambiae at the early phase of irrigated rice farming in the forest area of central Cameroon. Wellcome Open Res 2020. [DOI: 10.12688/wellcomeopenres.16064.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background:Cameroonian authorities have recently established irrigated rice projects across the country. The assessment of the impact of such projects in the transmission of vector-borne diseases, such as malaria, imposes to compare the situation before and after their implementation in a given locality. In Bankeng, a village in a forest area in Cameroon, no preliminary data on malaria transmission indicators was collected before the implantation of irrigated rice farming. To attempt to catch up for this shortcoming 6 months after the first rice seedlings were sown., the present study aimed to generate data which could serve as a baseline to assess the impact of irrigated rice farming in Bankeng.Methods: A cross-sectional study was performed at the end of the rainy season in July 2018. Mosquitoes were sampled by night collections on human volunteers, identified morphologically and members of different complexes further sorted to species using molecular tools.Plasmodiuminfectious status was determined by Taqman genotyping. To assess resistance profile to insecticides, WHO bioassays were performed using two-to-five days old femalesAn. gambiaes.l. reared from larval collections in Bankeng. Furthermore, the molecular basis of resistance were investigatedResults:An. gambiaes.l represented 98% of the 1087 mosquitoes collected withAnopheles gambiaeas the predominant species. The total human biting rate was 44.5 bites/person/night. Entomological inoculation rate was 3.8 ib/p/n. The BankengAn. gambiaepopulation exhibited a high level of resistance to almost all insecticides except to organophosphates with a high frequency of L1014F kdr mutation (93.9%) and a 6-fold over-expression ofCYP6P3P450 gene. Conclusion: In the absence of preliminary data before the implementation of the irrigated rice fields; the present study provides interesting data which could help for the future assessment of the impact of irrigated rice cultivation on malaria transmission in the locality of Bankeng.
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Nkemngo FN, Mugenzi LMJ, Terence E, Niang A, Wondji MJ, Tchoupo M, Nguete ND, Tchapga W, Irving H, Ntabi JDM, Agonhossou R, Boussougou-Sambe TS, Akoton RB, Koukouikila-Koussounda F, Pinilla YT, Ntoumi F, Djogbenou LS, Ghogomu SM, Ndo C, Adegnika AA, Borrmann S, Wondji CS. Elevated Plasmodium sporozoite infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon. Wellcome Open Res 2020; 5:146. [PMID: 33204845 PMCID: PMC7667521 DOI: 10.12688/wellcomeopenres.15818.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2020] [Indexed: 11/13/2023] Open
Abstract
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms. Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a village located 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adult progeny. Bioassays were performed to assess resistance profile to insecticides. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated. Results: Anopheles funestus s.s. was most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having a similar sporozoite rate. Both species exhibited high levels of resistance to pyrethroids (<40% mortality). An. gambiae s.s. was also resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively . Furthermore, the high pyrethroid/DDT resistances in An. gambiae s.s. corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b. Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the high Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.
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Affiliation(s)
- Francis N. Nkemngo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Microbiology and Parasitology, University of Buea, Buea, South West, 237, Cameroon
| | - Leon M. J. Mugenzi
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Ebai Terence
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Abdoulaye Niang
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Murielle J. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Micareme Tchoupo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Nguiffo D. Nguete
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Williams Tchapga
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
| | - Helen Irving
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jacques D. M. Ntabi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Romuald Agonhossou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Terence S. Boussougou-Sambe
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Romaric B. Akoton
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Felix Koukouikila-Koussounda
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
| | - Yudi T. Pinilla
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Francine Ntoumi
- Fondation Congolaise pour la Recherche Medicale (FCRM), Brazzaville, Congo
- Université Marien Ngouabi, Brazzaville, Congo
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Luc S. Djogbenou
- Institut Régional de Santé Publique, Université d'Abomey-Calavi, Cotonou, Benin
| | - Stephen M. Ghogomu
- Department of Biochemistry and Molecular Biology, University of Buea, Buea, South West, 237, Cameroon
| | - Cyrille Ndo
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Ayola A. Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- Eberhard Karls Universität Tübingen,, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), Tübingen, Germany
| | - Charles S. Wondji
- Department of Parasitology and Medical Entomology, Centre for Research in Infectious Diseases (CRID), Yaounde, Centre Region, 237, Cameroon
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Perugini E, Guelbeogo WM, Calzetta M, Manzi S, Virgillito C, Caputo B, Pichler V, Ranson H, Sagnon N, Della Torre A, Pombi M. Behavioural plasticity of Anopheles coluzzii and Anopheles arabiensis undermines LLIN community protective effect in a Sudanese-savannah village in Burkina Faso. Parasit Vectors 2020; 13:277. [PMID: 32487147 PMCID: PMC7268364 DOI: 10.1186/s13071-020-04142-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 05/21/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Despite the overall major impact of long-lasting insecticide treated nets (LLINs) in eliciting individual and collective protection to malaria infections, some sub-Saharan countries, including Burkina Faso, still carry a disproportionately high share of the global malaria burden. This study aims to analyse the possible entomological bases of LLIN limited impact, focusing on a LLIN-protected village in the Plateau Central region of Burkina Faso. METHODS Human landing catches (HLCs) were carried out in 2015 for 12 nights both indoors and outdoors at different time windows during the highest biting activity phase for Anopheles gambiae (s.l.). Collected specimens were morphologically and molecularly identified and processed for Plasmodium detection and L1014F insecticide-resistance allele genotyping. RESULTS Almost 2000 unfed An. gambiae (s.l.) (54% Anopheles coluzzii and 44% Anopheles arabiensis) females landing on human volunteers were collected, corresponding to a median number of 23.5 females/person/hour. No significant differences were observed in median numbers of mosquitoes collected indoors and outdoors, nor between sporozoite rates in An. coluzzii (6.1%) and An. arabiensis (5.5%). The estimated median hourly entomological inoculation rate (EIR) on volunteers was 1.4 infective bites/person/hour. Results do not show evidence of the biting peak during night hours typical for An. gambiae (s.l.) in the absence of bednet protection. The frequency of the L1014F resistant allele (n = 285) was 66% in An. coluzzii and 38% in An. arabiensis. CONCLUSIONS The observed biting rate and sporozoite rates are in line with the literature data available for An. gambiae (s.l.) in the same geographical area before LLIN implementation and highlight high levels of malaria transmission in the study village. Homogeneous biting rate throughout the night and lack of preference for indoor-biting activity, suggest the capacity of both An. coluzzii and An. arabiensis to adjust their host-seeking behaviour to bite humans despite bednet protection, accounting for the maintenance of high rates of mosquito infectivity and malaria transmission. These results, despite being limited to a local situation in Burkina Faso, represent a paradigmatic example of how high densities and behavioural plasticity in the vector populations may contribute to explaining the limited impact of LLINs on malaria transmission in holo-endemic Sudanese savannah areas in West Africa.
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Affiliation(s)
- Eleonora Perugini
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy
| | - Wamdaogo Moussa Guelbeogo
- Centre National de Recherche et Formation sur le Paludisme (CNRFP), Ouagadougou 01, BP 2208, Burkina Faso
| | - Maria Calzetta
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy
| | - Sara Manzi
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy
| | - Chiara Virgillito
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy.,Dipartimento di Biodiversità ed Ecologia Molecolare, Centro Ricerca e Innovazione, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
| | - Beniamino Caputo
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy
| | - Verena Pichler
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy
| | - Hilary Ranson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - N'Fale Sagnon
- Centre National de Recherche et Formation sur le Paludisme (CNRFP), Ouagadougou 01, BP 2208, Burkina Faso
| | - Alessandra Della Torre
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy.
| | - Marco Pombi
- Dipartimento di Sanità Pubblica e Malattie Infettive, Laboratory affiliated to Istituto Pasteur Italia, Fondazione Cenci Bolognetti, Sapienza Università di Roma, Rome, 00185, Italy.
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Athrey G, Popkin-Hall Z, Cosme LV, Takken W, Slotman MA. Species and sex-specific chemosensory gene expression in Anopheles coluzzii and An. quadriannulatus antennae. Parasit Vectors 2020; 13:212. [PMID: 32321556 PMCID: PMC7178735 DOI: 10.1186/s13071-020-04085-3] [Citation(s) in RCA: 4] [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: 09/02/2019] [Accepted: 04/15/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Olfactory cues drive mosquito behaviors such as host-seeking, locating sugar sources and oviposition. These behaviors can vary between sexes and closely related species. For example, the malaria vector Anopheles coluzzii is highly anthropophilic, whereas An. quadriannulatus is not. These behavioral differences may be reflected in chemosensory gene expression. METHODS The expression of chemosensory genes in the antennae of both sexes of An. coluzzii and An. quadriannulatus was compared using RNA-seq. The sex-biased expression of several genes in An. coluzzii was also compared using qPCR. RESULTS The chemosensory expression is mostly similar in the male antennae of An. coluzzii and An. quadriannulatus, with only a few modest differences in expression. A handful of chemosensory genes are male-biased in both species; the highly expressed gustatory receptor AgGr33, odorant binding proteins AgObp25, AgObp26 and possibly AgObp10. Although the chemosensory gene repertoire is mostly shared between the sexes, several highly female-biased AgOrs, AgIrs, and one AgObp were identified, including several whose expression is biased towards the anthropophilic An. coluzzii. Additionally, the expression of several chemosensory genes is biased towards An. coluzzii in both sexes. CONCLUSIONS Chemosensory gene expression is broadly similar between species and sexes, but several sex- biased/specific genes were identified. These may modulate sex- and species-specific behaviors. Although the male behavior of these species remains poorly studied, the identification of sex- and species-specific chemosensory genes may provide fertile ground for future work.
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Affiliation(s)
- Giridhar Athrey
- Department of Poultry Science, Texas A&M University, College Station, TX USA
| | | | - Luciano Veiga Cosme
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT USA
| | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, Wageningen, The Netherlands
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Böckelmann J, Tremetsberger K, Šumberová K, Kohl G, Grausgruber H, Bernhardt K. Genetic variation in an ephemeral mudflat species: The role of the soil seed bank and dispersal in river and secondary anthropogenic habitats. Ecol Evol 2020; 10:3620-3635. [PMID: 32313622 PMCID: PMC7160169 DOI: 10.1002/ece3.6109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 11/05/2019] [Accepted: 01/20/2020] [Indexed: 01/27/2023] Open
Abstract
Many ephemeral mudflat species, which rely on a soil seed bank to build up the next generation, are endangered in their natural habitat due to the widespread regulation of rivers. The aim of the present study was to elucidate the role of the soil seed bank and dispersal for the maintenance of genetic diversity in populations of near-natural river habitats and anthropogenic habitats created by traditional fish farming practices using Cyperus fuscus as a model. Using microsatellite markers, we found no difference in genetic diversity levels between soil seed bank and above-ground population and only moderate differentiation between the two fractions. One possible interpretation is the difference in short-term selection during germination under specific conditions (glasshouse versus field) resulting in an ecological filtering of genotypes out of the reservoir in the soil. River populations harbored significantly more genetic diversity than populations from the anthropogenic pond types. We suggest that altered levels and patterns of dispersal together with stronger selection pressures and historical bottlenecks in anthropogenic habitats are responsible for the observed reduction in genetic diversity. Dispersal is also supposed to largely prohibit genetic structure across Europe, although there is a gradient in private allelic richness from southern Europe (high values) to northern, especially north-western, Europe (low values), which probably relates to postglacial expansion out of southern and/or eastern refugia.
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Affiliation(s)
- Jörg Böckelmann
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life SciencesViennaAustria
- Present address:
Division of Tropical Ecology and Animal BiodiversityDepartment of Botany and Biodiversity ResearchUniversity of ViennaViennaAustria
| | - Karin Tremetsberger
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Kateřina Šumberová
- Department of Vegetation EcologyInstitute of BotanyThe Czech Academy of SciencesBrnoCzech Republic
| | - Gudrun Kohl
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life SciencesViennaAustria
- Present address:
Division of Microbial EcologyDepartment of Microbiology and Ecosystem ScienceUniversity of ViennaViennaAustria
| | - Heinrich Grausgruber
- Division of Plant BreedingDepartment of Crop SciencesUniversity of Natural Resources and Life SciencesViennaAustria
| | - Karl‐Georg Bernhardt
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life SciencesViennaAustria
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