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Zoungbédji DM, Padonou GG, Sovi A, Konkon AK, Salako AS, Azondékon R, Sidick A, Ahouandjinou JM, Towakinou L, Ossè R, Aïkpon R, Affoukou C, Baba-Moussa L, Akogbéto M. Bio-efficacy of Olyset ® Plus, PermaNet ® 3.0 and Interceptor ® G2 on pyrethroid-resistant populations of Anopheles gambiae s.l. prior to the June 2023 net distribution campaign in Benin, West Africa. Trop Med Health 2024; 52:34. [PMID: 38689360 PMCID: PMC11059851 DOI: 10.1186/s41182-024-00599-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 04/17/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND This study investigates the effectiveness of new-generation mosquito nets, like Olyset® Plus and PermaNet® 3.0, and dual-action nets such as Interceptor® G2, against pyrethroid-resistant Anopheles gambiae mosquitoes following the 2023 mass distribution of long-lasting insecticidal nets in Benin. METHODS We tested wild mosquito populations from six communes in Benin against various pyrethroid (permethrin 0.75%, alphacypermethrin 0.05%, and deltamethrin 0.05%) using WHO tube tests. Additionally, we exposed mosquitoes to chlorfenapyr 100 µg/ml using the CDC bottle bioassay method. A subset of mosquitoes underwent biochemical and PCR tests to check the overexpression of metabolic enzymes and the Kdr L1014F mutation. We evaluated the effectiveness of Olyset® Plus, PermaNet® 3.0, and Interceptor® G2 nets using cone and tunnel tests on both laboratory and field populations of An. gambiae. RESULTS Overall, the highest mortality rate was 60% with pyrethroid and 98 to100% with chlorfenapyr. In cone tests, all three types of nets induced mortality rates above 80% in the susceptible laboratory strain of An. gambiae. Notably, Olyset® Plus showed the highest mortality rates for pyrethroid-resistant mosquitoes in cone tests, ranging from 81.03% (95% CI: 68.59-90.13) in Djougou to 96.08% (95% CI: 86.54-99.52) in Akpro-Missérété. PermaNet® 3.0 had variable rates, from 42.5% (95% CI: 27.04-59.11) in Djougou to 58.54% (95% CI: 42.11-73.68) in Porto-Novo. However, revealed good results for Interceptor® G2, with 94% (95% CI: 87.40-97.77) mortality and 89.09% blood sampling inhibition in local populations of An. gambiae. In comparison, Interceptor® had lower rates of 17% (95% CI: 10.23-25.82) and 60%, respectively. CONCLUSION These results suggest that tunnel tests are effective for evaluating dual-active ingredient nets. Additionally, Interceptor® G2 and PBO nets like Olyset® Plus could be considered as alternatives against pyrethroid-resistant mosquitoes.
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Affiliation(s)
- David Mahouton Zoungbédji
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin.
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Germain Gil Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
- Faculty of Agronomy, University of Parakou, Parakou, Benin
- Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, UK
| | - Alphonse Keller Konkon
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | | | - Roseric Azondékon
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
| | - Aboubakar Sidick
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
| | | | - Linda Towakinou
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
| | - Razaki Ossè
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
- École de Gestion et d'exploitation des Systèmes d'élevage, Université Nationale d'Agriculture, Kétou, Benin
| | - Rock Aïkpon
- Programme National de Lutte Contre le Paludisme, Cotonou, Benin
- Université Nationale des Sciences, Technologies, Ingénierie et Mathématiques (UNSTIM), Abomey, Benin
| | | | - Lamine Baba-Moussa
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
- Laboratoire de Biologie et de Typage Moléculaire en Microbiologie (LBTMM), département de Biochimie et de Biologie Cellulaire (BBC), Université de Abomey-Calavi (UAC), Abomey-Calavi, Benin
| | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Benin
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Arich S, Assaid N, Weill M, Tmimi FZ, Taki H, Sarih M, Labbé P. Human activities and densities shape insecticide resistance distribution and dynamics in the virus-vector Culex pipiens mosquitoes from Morocco. Parasit Vectors 2024; 17:72. [PMID: 38374110 PMCID: PMC10877764 DOI: 10.1186/s13071-024-06164-1] [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: 10/24/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND Mosquitoes of the Culex pipiens complex are widely distributed vectors for several arboviruses affecting humans. Consequently, their populations have long been controlled using insecticides, in response to which different resistance mechanisms have been selected. Moreover, their ecological preferences and broad adaptability allow C. pipiens mosquitoes to breed in highly polluted water bodies where they are exposed to many residuals from anthropogenic activities. It has been observed for several mosquito species that anthropization (in particular urbanization and agricultural lands) can lead to increased exposure to insecticides and thus to increased resistance. The main objective of the present study was to investigate whether and how urbanization and/or agricultural lands had a similar impact on C. pipiens resistance to insecticides in Morocco. METHODS Breeding sites were sampled along several transects in four regions around major Moroccan cities, following gradients of decreasing anthropization. The imprint of anthropogenic activities was evaluated around each site as the percentage of areas classified in three categories: urban, agricultural and natural. We then assessed the frequencies of four known resistance alleles in these samples and followed their dynamics in five urban breeding sites over 4 years. RESULTS The distribution of resistance alleles revealed a strong impact of anthropization, in both agricultural and urbanized lands, although different between resistance mutations and between Moroccan regions; we did not find any clear trend in the dynamics of these resistance alleles during the survey. CONCLUSIONS Our study provides further evidence for the role of anthropic activities in the selection and maintenance of mutations selected for resistance to insecticides in mosquitoes. The consequences are worrying as this could decrease vector control capacities and thus result in epizootic and epidemic outbreaks. Consequently, concerted and integrated disease control strategies must be designed that include better management regarding the consequences of our activities.
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Affiliation(s)
- Soukaina Arich
- Institut des Sciences de l'Évolution de Montpellier, UMR 5554, CNRS-UM-IRD- EPHE), Université de Montpellier, Cedex 5, Montpellier, France
- Laboratory of Biology and Health, Faculty of Sciences Ben M'Sik, URAC34, Hassan II University of Casablanca, Casablanca, Morocco
- Laboratoire des Maladies Vectorielles (LMV), Institut Pasteur du Maroc, Casablanca, Morocco
| | - Najlaa Assaid
- Laboratoire des Maladies Vectorielles (LMV), Institut Pasteur du Maroc, Casablanca, Morocco
| | - Mylène Weill
- Institut des Sciences de l'Évolution de Montpellier, UMR 5554, CNRS-UM-IRD- EPHE), Université de Montpellier, Cedex 5, Montpellier, France
| | - Fatim-Zohra Tmimi
- Laboratoire des Maladies Vectorielles (LMV), Institut Pasteur du Maroc, Casablanca, Morocco
| | - Hassan Taki
- Laboratory of Biology and Health, Faculty of Sciences Ben M'Sik, URAC34, Hassan II University of Casablanca, Casablanca, Morocco
| | - M'hammed Sarih
- Laboratoire des Maladies Vectorielles (LMV), Institut Pasteur du Maroc, Casablanca, Morocco
| | - Pierrick Labbé
- Institut des Sciences de l'Évolution de Montpellier, UMR 5554, CNRS-UM-IRD- EPHE), Université de Montpellier, Cedex 5, Montpellier, France.
- Institut Universitaire de France, 1 rue Descartes, 75231, Cedex 05 Paris, France.
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Odjo EM, Tognidro M, Govoetchan R, Missihoun AA, Padonou GG, Ahouandjinou JM, Akinro B, Koukpo ZC, Tokponnon FT, Djenontin A, Agbangla C, Akogbeto MC. Malaria transmission potential of Anopheles gambiae s.l. in indoor residual spraying areas with clothianidin 50 WG in northern Benin. Trop Med Health 2024; 52:18. [PMID: 38336760 PMCID: PMC10854093 DOI: 10.1186/s41182-024-00582-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/17/2024] [Indexed: 02/12/2024] Open
Abstract
The study objective was to assess the frequency of the kdr-L995F and ace-1 G280S genetic mutations in Anopheles gambiae s.l. mosquitoes and examine their ability to transmit Plasmodium falciparum in areas where indoor residual spraying (IRS) was implemented with Clothianidin 50 WG. The study was conducted in six communes in the Alibori and Donga departments of which four were IRS-treated and two were untreated and served as control. Post-IRS monthly samples of adult mosquitoes were collected in study communes using human landing catches (HLC). An. gambiae s.l. specimens were processed to detect kdr-L995F and ace-1 G280S mutations via PCR as well as Plasmodium falciparum infectivity through CSP ELISA. Our data revealed a high and similar allelic frequency for the kdr-L995F mutation in both treated and control communes (79% vs. 77%, p = 0.14) whilst allelic frequency of the ace-1 G280S mutation was lower across the study area (2-3%, p = 0.58). The sporozoite rate was 2.6% and 2.4% respectively in treated and untreated communes (p = 0.751). No association was found between Plasmodium falciparum infection in Anopheles gambiae s.l. vectors and carriage of kdr-L995F and ace-1 G280S mutations regardless of genotypes. The study findings underline the need for an integrated approach to malaria control, combining different control methods to effectively target transmission. Regular monitoring of insecticide resistance and genetic mutations is essential to guide control strategies.
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Affiliation(s)
- Esdras Mahoutin Odjo
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin.
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Mathilde Tognidro
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Renaud Govoetchan
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Université de Parakou, Parakou, Benin
| | - Antoine Abel Missihoun
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Gil Germain Padonou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Juvenal Minassou Ahouandjinou
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
| | | | - Filémon T Tokponnon
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Ecole polytechnique d'Abomey Calavi, Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Armel Djenontin
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Clement Agbangla
- Centre de Recherche Entomologique de Cotonou, Cotonou, Benin
- Direction Générale de la Recherche Scientifique, Ministère de l'Enseignement Supérieur et de la Recherche Scientifique, Cotonou, Benin
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Medjigbodo AA, Djihinto OY, Salavi EBJ, Sonounameto EG, Abbey E, Djossou L, Djogbénou LS. Organophosphate Insecticide Exposure Impacts Reproductive Success in Insensitive Acetylcholinesterase Anopheles gambiae Mosquitoes. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.903654] [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
Extensive use of insecticides has led to the selection of resistance alleles in malaria vectors threatening the control programs. Even if mosquitoes are not killed directly in the contact of insecticide-treated bed nets, their capacity to transmit malaria parasite could be decreased because of the consequences on their life-history traits after repeated exposure. The current work investigated the effects of organochlorine, carbamate, organophosphate, and pyrethroid insecticide exposure on the reproductive success in Anopheles gambiae s.s. Two Anopheles gambiae strains, AcerKis, KisKdr, were used. According to WHO recommendations, female mosquitoes of these resistant strains were exposed to discriminant doses of DDT, chlorpyriphos-methyl, bendiocarb, and permethrin insecticides. Surviving mosquitoes were then fed and allowed to lay eggs. Fecundity was assessed by examining the number of eggs per mosquito, the number of larvae per egg batch and larval hatching rates were used to evaluate the fertility. The data showed that AcerKis females surviving chlorpyriphos-methyl exposure significantly laid few eggs. No significant difference in the hatching rate was noticed in AcerKis females exposed to bendiocarb compared to their control. No significant effect on the fecundity and fertility was observed in KisKdr females exposed to permethrin. Our finding showed that organophosphate insecticides represented here by chlorpyriphos-methyl could hamper egg-laying in insensitive acetylcholinesterase An. gambiae female mosquitoes. This knowledge could help design alternative vector control strategies targeting fecundity and fertility in resistant malaria vectors.
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Ratnadass A, Martin T. Crop protection practices and risks associated with infectious tropical parasitic diseases. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 823:153633. [PMID: 35124028 DOI: 10.1016/j.scitotenv.2022.153633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 01/28/2022] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Two recent literature reviews have shown that: i) agroecological crop protection (ACP) practices generally reduce risks of viral zoonoses, unlike conventional (agrochemical-based) practices which tend to increase them; ii) substitution-based crop protection (CP) practices (mainly biocontrol-based) could result in fewer health risks from bacterial infectious diseases. Here, we present an analysis of the scientific literature to determine to what extent the conclusions regarding viruses or bacteria can be extended to infectious diseases caused by protozoan or helminthic parasites. This analysis of cases of both vector-transmitted and water- or food-borne parasitic diseases, shows, in terms of reduction of health risks: i) an overall negative effect arising from the use of synthetic plant protection products; ii) the relevance of substitution CP practices not strictly under the ACP banner. On the other hand, the public and veterinary health issue of antiparasitic resistance is not affected by CP practices. The positive effects at the large spatio-temporal scales of ACP approaches remain valid, although to a slightly lesser extent than for bacterial diseases and viral zoonoses, in particular through biodiversity conservation which fosters natural regulations and control, preventing the undesirable effects of synthetic pesticides.
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Affiliation(s)
- Alain Ratnadass
- CIRAD, UPR HortSys, F-97455 Saint-Pierre, Réunion, France; HortSys, Univ Montpellier, CIRAD, Montpellier, France.
| | - Thibaud Martin
- HortSys, Univ Montpellier, CIRAD, Montpellier, France; CIRAD, UPR HortSys, Abidjan, Côte d'Ivoire
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Fodjo BK, Kropf A, Gonse Zoh M, Gba Sadia C, France-Paraudie Kouadio A, Guibéhi Benjamin K, Seidou Mouhamadou C. Impact of sublethal pyrethroid exposure on resistant Anopheles gambiae mosquitoes’ fitness. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.17074.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: There is increasing evidence of insecticide resistance spreading among wild mosquito populations, which is widely believed to compromise vector control once it reaches a threshold that enables mosquitoes to survive exposure to long lasting treated bed-net (LLIN) or indoor residual spraying (IRS). However, very little is known about the long-term impact of insecticide resistance on malaria transmission, which makes the consequence of insecticide resistance spreading difficult to predict. Methods: To gain more clarity, we have assessed five life-history traits of a resistant Anopheles gambiae laboratory strain that was repeatedly exposed to a LLIN and compared with individuals issued from the same strain but exposed to an untreated bed-net. Results: Out of the five measured life-history traits, four were significantly affected by exposure to insecticides. Indeed, the Kolmogorov-Smirnov non-parametric test revealed a significant (i) drop in blood feeding mean rates (P=0.000000494), (ii) increase in 24-hours post-exposure (P= 0.000008559) and (iii) end of gonotrophic cycle mortality (P =0.0005749), and (iv) drop in egg laying rate (P=0.000107) when mosquitoes were exposed. Conclusion: Our study shows that in a context of widespread of resistance to insecticides, current pyrethroid-based vector control tools can still confer protection against malaria
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Fodjo BK, Kropf A, Gonse Zoh M, Gba Sadia C, France-Paraudie Kouadio A, Guibéhi Benjamin K, Seidou Mouhamadou C. Impact of sublethal pyrethroid exposure on resistant Anopheles gambiae mosquitoes’ fitness. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.17074.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: There is increasing evidence of insecticide resistance spreading among wild mosquito populations, which is widely believed to compromise vector control once it reaches a threshold that enables mosquitoes to survive exposure to long lasting treated bed-net (LLIN) or indoor residual spraying (IRS). However, very little is known about the long-term impact of insecticide resistance on malaria transmission, which makes the consequence of insecticide resistance spreading difficult to predict. Methods: To gain more clarity, we have assessed four life-history traits of a resistant Anopheles gambiae laboratory strain that was repeatedly exposed to a LLIN and compared with individuals issued from the same strain but exposed to an untreated bed-net. Results: The non-parametric Kruskal-Wallis test did not show any significant impact of gonotrophic cycle on the five traits. However, the Kolmogorov-Smirnov non-parametric test revealed a significant (i) drop in blood feeding mean rates (D = 0.800; P< 0.0001), (ii) increase in 24-hours post-exposure (D = 0.600; P< 0.001) and (iii) end of gonotrophic cycle mortality (D = 0.611; P <0.006), and (iv) drop in egg laying rate (D = 0.730, P< 0.0001) when mosquitoes were exposed. Surprisingly, there was rather an upward trend in the number of L3 larvae/female mosquito for the exposed group comparing to the unexposed one, although the difference was not significant (D = 0.417, P> 0.05). Conclusion: Our study shows that in a context of widespread of resistance to insecticides, current pyrethroid-based vector control tools can still confer protection against malaria.
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Zhang H, Li M, Tan R, Deng C, Huang B, Wu Z, Zheng S, Guo W, Tuo F, Yuan Y, Bandeira CA, Rompão DH, Xu Q, Song J, Wang Q. Presence of L1014F Knockdown-Resistance Mutation in Anopheles gambiae s.s. From São Tomé and Príncipe. Front Cell Infect Microbiol 2021; 11:633905. [PMID: 34307185 PMCID: PMC8295031 DOI: 10.3389/fcimb.2021.633905] [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: 11/26/2020] [Accepted: 06/08/2021] [Indexed: 11/18/2022] Open
Abstract
Malaria, one of the most serious parasitic diseases, kills thousands of people every year, especially in Africa. São Tomé and Príncipe are known to have stable transmission of malaria. Indoor residual spraying (IRS) of insecticides and long-lasting insecticidal nets (LLIN) are considered as an effective malaria control interventions in these places. The resistance status of Anopheles gambiae s.s. from Agua Grande, Caue, and Lemba of São Tomé and Príncipe to insecticides, such as dichlorodiphenyltrichloroethane (DDT) (4.0%), deltamethrin (0.05%), permethrin (0.75%), fenitrothion (1.0%), and malathion (5.0%), were tested according to the WHO standard protocol. DNA extraction, species identification, as well as kdr and ace-1R genotyping were done with the surviving and dead mosquitoes post testing. They showed resistance to cypermethrin with mortality rates ranging from 89.06% to 89.66%. Mosquitoes collected from Agua Grande, Caue, and Lemba displayed resistance to DDT and fenitrothion with mortality rates higher than 90%. No other species were detected in these study localities other than Anopheles gambiae s.s. The frequency of L1014F was high in the three investigated sites, which was detected for the first time in São Tomé and Príncipe. No ace-1R mutation was detected in all investigated sites. The high frequency of L1014F showed that kdr L1014F mutation might be related to insecticide resistance to Anopheles gambiae s.s. populations from São Tomé and Príncipe. Insecticide resistance status is alarming and, therefore, future malaria vector management should be seriously considered by the government of São Tomé and Príncipe.
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Affiliation(s)
- Hongying Zhang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,Science and Technology Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Mingqiang Li
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ruixiang Tan
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Changsheng Deng
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Bo Huang
- Science and Technology Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhibin Wu
- The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Shaoqing Zheng
- Science and Technology Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wenfeng Guo
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Fei Tuo
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yueming Yuan
- Science and Technology Institute, Guangzhou University of Chinese Medicine, Guangzhou, China
| | | | | | - Qin Xu
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jianping Song
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qi Wang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Ministry of Health, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
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Medjigbodo AA, Djogbenou LS, Koumba AA, Djossou L, Badolo A, Adoha CJ, Ketoh GK, Mavoungou JF. Phenotypic Insecticide Resistance in Anopheles gambiae (Diptera: Culicidae): Specific Characterization of Underlying Resistance Mechanisms Still Matters. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:730-738. [PMID: 33043968 PMCID: PMC7954100 DOI: 10.1093/jme/tjaa195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Indexed: 06/11/2023]
Abstract
An effective control of malaria vectors requires an extensive knowledge of mechanisms underlying the resistance-phenotypes developed by these vectors against insecticides. We investigated Anopheles gambiae mosquitoes from Benin and Togo for their intensity of insecticide resistance and we discussed the involvement of genotyped mechanisms in the resistance-phenotypes observed. Three- to five-day-old adult mosquitoes emerged from field and laboratory An. gambiae larvae were assayed using WHO tube intensity tests against various doses of deltamethrin: 1× (0.05%); 2× (0.1%); 5× (0.25%); 7.5× (0.375%) and those of pirimiphos-methyl: 0.5× (0.125%); 1× (0.25%). Members of An. gambiae complex were screened in field populations using polymerase chain reaction (PCR) assays. The presence of kdrR(1014F/1014S) and ace-1R(119S) mutations was also investigated using TaqMan and PCR-RFLP techniques, respectively. Anopheles gambiae from field were very resistant to deltamethrin, whereas KisKdr and AcerKdrKis strains displayed 100% mortality rates at 2× the diagnostic dose. In contrast, the field mosquitoes displayed a low resistance-intensity against 1× the diagnostic dose of pirimiphos-methyl, whereas AcerKis and AcerKdrKis strains showed susceptibility at 0.5× the diagnostic dose. Anopheles gambiae s.s., Anopheles coluzzii, and Anopheles arabiensis were identified. Allelic frequencies of kdrR (1014F) and ace-1R (119S) mutations in the field populations varied from 0.65 to 1 and 0 to 0.84, respectively. The field An. gambiae displayed high-resistance levels against deltamethrin and pirimiphos-methyl when compared with those of the laboratory An. gambiae-resistant strains. These results exhibit the complexity of underlying insecticide resistance mechanisms in these field malaria vectors.
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Affiliation(s)
- Adandé A Medjigbodo
- Laboratory of Infectious Vector-Borne Diseases, Regional Institute of Public Health/University of Abomey-Calavi, Cotonou, Benin
- Laboratory of Fundamental and Applied Entomology, University Joseph KI-ZERBO, BP, Burkina Faso, West Africa
| | - Luc S Djogbenou
- Laboratory of Infectious Vector-Borne Diseases, Regional Institute of Public Health/University of Abomey-Calavi, Cotonou, Benin
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Aubin A Koumba
- Laboratory of Infectious Vector-Borne Diseases, Regional Institute of Public Health/University of Abomey-Calavi, Cotonou, Benin
- University of Science and Technology of Masuku (USTM), BP, Franceville, Gabon
| | - Laurette Djossou
- Laboratory of Infectious Vector-Borne Diseases, Regional Institute of Public Health/University of Abomey-Calavi, Cotonou, Benin
| | - Athanase Badolo
- Laboratory of Fundamental and Applied Entomology, University Joseph KI-ZERBO, BP, Burkina Faso, West Africa
| | - Constantin J Adoha
- Laboratory of Infectious Vector-Borne Diseases, Regional Institute of Public Health/University of Abomey-Calavi, Cotonou, Benin
| | | | - Jacques F Mavoungou
- University of Science and Technology of Masuku (USTM), BP, Franceville, Gabon
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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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Ahadji-Dabla KM, Romero-Alvarez D, Djègbè I, Amoudji AD, Apétogbo GY, Djouaka R, Oboussoumi K, Aawi A, Atcha-Oubou T, Peterson AT, Ketoh GK. Potential Roles of Environmental and Socio-Economic Factors in the Distribution of Insecticide Resistance in Anopheles gambiae sensu lato (Culicidae: Diptera) Across Togo, West Africa. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1168-1175. [PMID: 32112104 DOI: 10.1093/jme/tjaa023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 06/10/2023]
Abstract
Vector control strategies recommended by the World Health Organization are threatened by resistance of Anopheles mosquitoes to insecticides. Information on the distribution of resistant genotypes of malaria vectors is increasingly needed to address the problem. Ten years of published and unpublished data on malaria vector susceptibility/resistance and resistance genes have been collected across Togo. Relationships between the spatial distribution of resistance status and environmental, socio-economic, and landscape features were tested using randomization tests, and calculating Spearman rank and Pearson correlation coefficients between mosquito mortality and different gridded values. Anopheles gambiae sensu lato was resistant to DDT, pyrethroids, and the majority of carbamates and organophosphates. Three sibling species were found (i.e., An. gambiae, Anopheles coluzzii, and Anopheles arabiensis) with four resistance genes, including kdr (L1014F, L1014S, and N1575Y) and ace1 (G119S). The most frequent resistance gene was L1014F. Overall, no association was found between the susceptibility/resistance status and environmental features, suggesting that evolution of resistance may be most closely related to extreme selection from local insecticide use. Nevertheless, further research is necessary for firm conclusions about this lack of association, and the potential role of landscape characteristics such as presence of crops and percentage of tree cover.
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Affiliation(s)
- Koffi Mensah Ahadji-Dabla
- Department of Zoology and Animal Biology, Faculty of Sciences, Université de Lomé, Lomé, Togo
- Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS
| | - Daniel Romero-Alvarez
- Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS
| | - Innocent Djègbè
- National University of Sciences, Technologies, Engineering and Mathematics, Ecole Normale Supérieure de Natitingou, Natitingou, BP, Benin
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, Benin
| | - Adjovi Djifa Amoudji
- Department of Zoology and Animal Biology, Faculty of Sciences, Université de Lomé, Lomé, Togo
| | - Georges Yawo Apétogbo
- Department of Zoology and Animal Biology, Faculty of Sciences, Université de Lomé, Lomé, Togo
| | - Rousseau Djouaka
- National University of Sciences, Technologies, Engineering and Mathematics, Ecole Normale Supérieure de Natitingou, Natitingou, BP, Benin
| | | | - Agnidoufèyi Aawi
- National Malaria Control Programme/Ministry of Health, Lomé Togo
| | | | - A Townsend Peterson
- Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS
| | - Guillaume Koffivi Ketoh
- Department of Zoology and Animal Biology, Faculty of Sciences, Université de Lomé, Lomé, Togo
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12
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Assogba BS, Pasteur N, Makoundou P, Unal S, Baba-Moussa L, Labbé P, Weill M. Dynamic of resistance alleles of two major insecticide targets in Anopheles gambiae (s.l.) populations from Benin, West Africa. Parasit Vectors 2020; 13:134. [PMID: 32171326 PMCID: PMC7071764 DOI: 10.1186/s13071-020-4006-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insecticide resistance is a growing concern for malaria control and vector control effectiveness relies on assessing it distribution and understanding its evolution. METHODS We assessed resistance levels and the frequencies of two major target-site mutations, L1014F-VGSC and G119S-ace-1, conferring resistance to pyrethroids (PYRs) and carbamates/organophosphates (CXs/OPs) insecticides. These data were compared to those acquired between 2006 and 2010 to follow resistance evolutionary trends over ten years. RESULTS We report the results of a 3-year survey (2013-2015) of insecticide resistance in 13 localities across the whole country of Benin. Permethrin (PYR) resistance was found in all populations tested, L1014F-VGSC being almost fixed everywhere, while bendiocarb resistance was limited to a few localities, G119S-ace-1 remaining rare, with very limited variations during surveyed period. Interestingly, we found no effect of the type of insecticide pressure on the dynamics of these mutations. CONCLUSIONS These results confirm both the high prevalence of PYR resistance and the potential of CXs/OPs as short- to medium-term alternatives in Benin. They also underline the need for regular resistance monitoring and informed management in their usage, as the G119S-ace-1 mutation is already present in Benin and surrounding countries. Their unwise usage would rapidly lead to its spread, which would jeopardize PYR-resistant Anopheles control.
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Affiliation(s)
- Benoît S. Assogba
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
- Faculté des Sciences et Techniques, Laboratoire de Biologie et de Typage Moléculaire en Microbiologie, Université d’Abomey Calavi, 05 BP 1604, Cotonou, Benin
- Institut Régional de Santé Publique, Université d’Abomey Calavi, 01 BP 918, Cotonou, Benin
- Disease Control and Elimination Department, Medical Research Council, Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, Gambia
| | - Nicole Pasteur
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Patrick Makoundou
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Sandra Unal
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Lamine Baba-Moussa
- Faculté des Sciences et Techniques, Laboratoire de Biologie et de Typage Moléculaire en Microbiologie, Université d’Abomey Calavi, 05 BP 1604, Cotonou, Benin
| | - Pierrick Labbé
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Mylène Weill
- Institut des Sciences de l’Evolution de Montpellier (ISEM), UMR CNRS-IRD-EPHE-Université de Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
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13
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Namountougou M, Soma DD, Kientega M, Balboné M, Kaboré DPA, Drabo SF, Coulibaly AY, Fournet F, Baldet T, Diabaté A, Dabiré RK, Gnankiné O. Insecticide resistance mechanisms in Anopheles gambiae complex populations from Burkina Faso, West Africa. Acta Trop 2019; 197:105054. [PMID: 31175862 DOI: 10.1016/j.actatropica.2019.105054] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 10/26/2022]
Abstract
Vector control constitutes a fundamental approach in reducing vector density and the efficient option to break malaria transmission in Africa. Malaria vectors developed resistance to almost all classes of insecticides recommended by WHO for vector control in most places of African countries and may compromise the vector control strategies. This study updated the resistance status of Anopheles gambiae complex populations to insecticides recommended for vector control in the western part of Burkina Faso. Insecticide susceptibility bioassays were performed on seven natural populations of An. gambiae complex from western Burkina Faso in the 2016 rainy season using the WHO protocol. Biochemical assays were carried out according to the WHO protocol on the same populations to estimate detoxifying enzymes activities including non-specific esterases (NSEs), oxidases (cytochrome P450) and Glutathione-S-Transferases (GSTs). Polymerase Chain Reactions (PCRs) were performed for the identification of the An. gambiae complex species as well as the detection of kdr-west and ace-1 mutations. Susceptibility bioassays showed that An. gambiae complex was multi-resistant to pyrethroids, DDT and carbamates in almost all areas. The mortality rates ranged from 10 to 38%, 2.67 to 59.57% and 64.38 to 98.02% for Deltamethrin, DDT and Bendiocarb respectively. A full susceptibility (100%) to an organophosphate, the Chlorpyrifos-methyl, was observed at the different sites. Three (3) species of the An. gambiae complex were identified: An. gambiae s.s, An. coluzzii and An. arabiensis. The frequencies of the kdr-w mutation were highly widespread (0.66 to 0.98) among the three species of the complex. The ace-1 mutation was detected at low frequencies (0 to 0.12) in An. gambiae s.s and An. coluzzii. A high level of GSTs and NSEs were observed within the different populations of the An. gambiae complex. Several mechanisms of insecticide resistance were found simultaneously in the same populations of An. gambiae complex conferring high multi-resistance to DDT, Carbamate and Pyrethroids. The full susceptibility of An. gambiae complex to organophosphates is a useful data for the national malaria control program in selecting the most appropriate products to both maintain the effectiveness of vector control strategies and best manage insecticide resistance as well as developing new alternative strategies for the control of major malaria vectors in Burkina Faso.
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14
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Ahadji-Dabla KM, Amoudji AD, Nyamador SW, Apétogbo GY, Chabi J, Glitho IA, Ketoh GK. High Levels of Knockdown Resistance in Anopheles coluzzii and Anopheles gambiae (Diptera: Culicidae), Major Malaria Vectors in Togo, West Africa: A 2011 Monitoring Report. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1159-1164. [PMID: 30924857 DOI: 10.1093/jme/tjz030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Indexed: 06/09/2023]
Abstract
A survey of susceptibility to DDT, deltamethrin, bendiocarb, and chlorpyrifos-methyl was conducted in five localities in 2011 in Togo, West Africa, to assess the insecticide resistance status of Anopheles gambiae s.l. (Diptera: Culicidae). Female populations of An. gambaie s.l. emerged from collected larvae (F0) were exposed to insecticide-impregnated papers using World Health Organization test kits for adult mosquitoes; the susceptible reference strain Kisumu was used as a control. Resistance to DDT and deltamethrin was observed within the mosquito populations tested. Anopheles gambiae s.s. and Anopheles coluzzii represented the only species recorded in the study sites. The frequency of knockdown resistance (kdr L1014F) mutation determined using polymerase chain reaction diagnostic tests was lower in An. gambiae than in An. coluzzii in all of the localities except Kolokopé. Further investigations of An. gambiae s.l. resistance are needed in Togo to help the National Malaria Control Programme in vector control decision making and implementation of resistance management strategy.
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Affiliation(s)
- Koffi Mensah Ahadji-Dabla
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
- Biodiversity Institute, University of Kansas, Lawrence, KS
| | - Adjovi Djifa Amoudji
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
| | - Seth Wolali Nyamador
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
| | - Georges Yawo Apétogbo
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
| | - Joseph Chabi
- Department of Parasitology, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Legon, Accra, Ghana
| | - Isabelle Adolé Glitho
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
| | - Guillaume Koffivi Ketoh
- Department of Zoology and Animal Biology, Faculty of Sciences, University of Lomé, Lomé, Togo
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Abagli AZ, Alavo TBC, Perez-Pacheco R, Platzer EG. Efficacy of the mermithid nematode, Romanomermis iyengari, for the biocontrol of Anopheles gambiae, the major malaria vector in sub-Saharan Africa. Parasit Vectors 2019; 12:253. [PMID: 31118105 PMCID: PMC6530168 DOI: 10.1186/s13071-019-3508-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 05/14/2019] [Indexed: 11/25/2022] Open
Abstract
Background The intensive use of chemical insecticides against mosquitoes has led to the development of widespread insecticide resistance. Control of Anopheles mosquitoes in malaria endemic areas of sub-Saharan Africa has become increasingly difficult. There is an urgent need for malaria control programmes to adopt more integrated mosquito management approaches that include sustainable, nonchemical solutions. The mermithid nematode Romanomermis iyengari is one of several natural control alternatives to synthetic pesticides for mosquito suppression. This study evaluated the effectiveness of the nematode R. iyengari for control of Anopheles gambiae. Methods The nematode R. iyengari was mass-produced, and pre-parasitic stage (J2) were used for laboratory and field experiments. In laboratory experiments, two concentrations of pre-parasitics (5 and 10 J2 per larva) were tested against first- (L1), second- (L2) and third-instar (L3) larvae of An. gambiae. Infected larvae were observed daily to determine their mortality rate and the number of post-parasitic nematodes emerging from dead larvae. In field experiments, 3500, 4000 and 5000 J2/m2 were sprayed in separate natural Anopheles breeding sites. After treatment, the larval mosquito density in the breeding sites was assessed every 5–7 days. Results Laboratory results showed that larval An. gambiae is susceptible to nematode infection: 100% L1 larvae died within 24 hours post-treatment, and 100% of both L2 and L3 larvae died within 7 days, regardless of nematode concentrations. The average number of post-parasitic nematodes emerging per larva increased with increasing nematode concentration. In field experiments, the monthly applications of 3500 to 5000 pre-parasitic nematodes per m2 eliminated larval mosquito development in Anopheles- and mixed breeding sites. Larval mosquito density dramatically decreased five days after the first treatment in all treated sites and was maintained at a very low level during the whole experimental period. Basically, only early instar larva were detected in treated sites throughout the test period. The average number of post-parasitic nematodes emerging per larva collected in treated sites was 1.45, 2, and 5.7 respectively for sites treated with 3500, 4000, and 5000 J2/m2. Conclusions Malaria mosquito larvae is susceptible to R. iyengari infection in West Africa. Parasitism intensity depends on tested nematode concentrations. Monthly application of 3500 J2/ m2 was enough to control effectively larval An. gambiae in wetlands and floodable locations in West Africa.
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Affiliation(s)
- Ayaba Z Abagli
- Laboratoire d'Entomology Appliquée/Centre Edward Platzer, Université d'Abomey-Calavi, BP:215, Godomey, Benin
| | - Thiery B C Alavo
- Laboratoire d'Entomology Appliquée/Centre Edward Platzer, Université d'Abomey-Calavi, BP:215, Godomey, Benin.
| | - Rafael Perez-Pacheco
- CIIDIR Oaxaca, Instituto Politécnico Nacional, Xoxocotlan, Oaxaca, 71230, Mexico
| | - Edward G Platzer
- Department of Nematology, University of California, Riverside, CA, 92521-0415, USA
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16
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Salako AS, Ahogni I, Aïkpon R, Sidick A, Dagnon F, Sovi A, Sominahouin AA, Agossa F, Iyikirenga L, Akogbeto MC. Insecticide resistance status, frequency of L1014F Kdr and G119S Ace-1 mutations, and expression of detoxification enzymes in Anopheles gambiae (s.l.) in two regions of northern Benin in preparation for indoor residual spraying. Parasit Vectors 2018; 11:618. [PMID: 30509288 PMCID: PMC6278060 DOI: 10.1186/s13071-018-3180-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/30/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aims to provide baseline data on the resistance status to insecticides, the frequency of mechanisms involved and the impact of the association with the synergist piperonyl butoxide (PBO) on resistant Anopheles gambiae (s.l.) populations in two regions of northern Benin, prior to an indoor residual spraying campaign and introduction of next generation long-lasting insecticidal nets (LLINs) incorporating PBO. METHODS Adult Anopheles gambiae (s.l.) originating from larvae collected in two study regions (Alibori within the Kandi-Gogounou-Segbana districts and Donga within the Djougou-Copargo-Ouake districts) were tested with impregnated papers (bendiocarb 0.1%, pirimiphos-methyl 0.25%, permethrin 0.75% and deltamethrin 0.05%). The synergist PBO was used to check for the involvement of detoxification enzymes in pyrethroid resistant populations. Molecular analyses were performed for the identification of species within the Anopheles gambiae (s.l.) complex and kdr L1014F and G119S Ace-1 mutations. Biochemical assays assessed the activity of detoxification enzymes. RESULTS Anopheles gambiae (s.l.) was resistant to pyrethroids, with a mortality range of 25-83% with deltamethrin and 6-55% with permethrin. A significant increase in mortality was observed after pre-exposure to PBO for both deltamethrin (63-99%) and permethrin (56-99%). With bendiocarb, An. gambiae (s.l.) were susceptible in Kandi (99% mortality), with possible resistance (92-95%) recorded in Djougou, Copargo, Gogounou, Ouake and Segbana. All study populations were fully susceptible to pirimiphos-methyl. The frequencies of resistant mutations varied according to species and sites: 0.67-0.88 for L1014F kdr and 0-0.06 for G119S Ace-1. Three study locations (Djougou, Gogounou and Kandi) showed high oxidase activity and four sites (Djougou, Ouake, Copargo and Kandi) showed elevated esterase activity. CONCLUSIONS This study confirms resistance to pyrethroids and suggests emerging bendiocarb resistance in An. gambiae (s.l.) populations in northern Benin. However, recovery of susceptibility to pyrethroids after PBO exposure, and susceptibility to organophosphates in the An. gambiae (s.l.) populations indicate that next generation LLINs incorporating PBO synergist combined with an indoor residual spraying (IRS) campaign with organophosphate insecticides may be regarded as alternative control tools.
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Affiliation(s)
- Albert Sourou Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Idelphonse Ahogni
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Rock Aïkpon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Technologies, Ingénierie et Mathématiques, Université Nationale des Sciences, Abomey, Bénin
| | - Aboubakar Sidick
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | - Fortune Dagnon
- US Agency for International Development, US President's Malaria Initiative, Cotonou, Benin
| | - Arthur Sovi
- PMI VectorLink project, Abt associates, Bamako, Mali
| | - André Aimé Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences Humaines et Sociales de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Fiacre Agossa
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
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Djènontin A, Moiroux N, Bouraïma A, Zogo B, Sidick I, Corbel V, Pennetier C. Field efficacy of a new deltamethrin long lasting insecticidal net (LifeNet©) against wild pyrethroid-resistant Anopheles gambiae in Benin. BMC Public Health 2018; 18:947. [PMID: 30068334 PMCID: PMC6090760 DOI: 10.1186/s12889-018-5876-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/24/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malaria vector control is mostly based on Long-Lasting Insecticidal Nets (LLIN). To date, all LLINs fully recommended by the World Health Organization Pesticide Scheme (WHOPES) are made of polyester or polyethylene. In this context, a new LLIN named LifeNet©, made of polypropylene fiber is developed. According to the manufacturer, LifeNet©is made of soft filament, has a greater mechanical strength, a superior insecticide wash resistance with a short insecticide regeneration time, a better flammability profile and a better environmental profile compared to polyester or polyethylene nets. METHODS Through a WHOPES supervised trial, the efficacy of LifeNet© was evaluated in Benin in experimental huts against free-flying wild mosquitoes. RESULTS LifeNet© has equal or better performances in terms of wash resistance, exophily, blood feeding inhibition and mortality compared to conventionally treated nets (CTN) treated with deltamethrin at 25 mg/m2 and washed to just before exhaustion. CONCLUSIONS The efficacy of LifeNet© observed in this trial indicates that this net fulfill World Health Organization Pesticide Scheme (WHOPES) requirement for Long Lasting technology in Phase II. Throughout a Phase III trial currently ongoing in Southern Benin, the durability and the acceptability of this long-lasting insecticidal mosquito nets will be assessed under community conditions.
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Affiliation(s)
- Armel Djènontin
- Faculté des Sciences et Techniques-Université d’Abomey-Calavi, Cotonou, Benin
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | - Nicolas Moiroux
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
- IRSS, CNRST, Bobo Dioulasso, Ouagadougou, Burkina Faso
| | - Aziz Bouraïma
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
| | - Barnabas Zogo
- MIVEGEC, IRD, CNRS, Univ Montpellier, Cotonou, Benin
| | | | - Vincent Corbel
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
| | - Cédric Pennetier
- MIVEGEC, IRD, CNRS, Univ Montpellier, Montpellier, France
- IPR, INSP, Bouaké, Côte d’Ivoire
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18
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Djègbè I, Akoton R, Tchigossou G, Ahadji-Dabla KM, Atoyebi SM, Adéoti R, Zeukeng F, Ketoh GK, Djouaka R. First report of the presence of L1014S Knockdown-resistance mutation in Anopheles gambiae s.s and Anopheles coluzzii from Togo, West Africa. Wellcome Open Res 2018; 3:30. [PMID: 29707654 PMCID: PMC5909049 DOI: 10.12688/wellcomeopenres.13888.1] [Citation(s) in RCA: 15] [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: 03/06/2018] [Indexed: 11/30/2022] Open
Abstract
Background: To optimize the success of insecticide-based malaria control intervention, knowledge of the distribution of Anopheles gambiae species and insecticide resistance mechanisms is necessary. This paper reported an updated data on pyrethroids/DDT resistance in the An. gambiae s.l population from Togo. Methods: From December 2013 to April 2015, females of indoor-resting An. gambiae s.l were captured in three locations belonging to three different ecological zones. Resistance to DDT, permethrin and deltamethrin was screened in F1 progeny of collected mosquitoes using WHO susceptibility tests. The identification of species of An. gambiae complex and the detection of kdr and ace.1 R allele were carried out using DNA-based molecular techniques. Results:An. gambiae from Kovié and Nangbéto were highly resistant to DDT and permethrin with mortalities rate ranging from 0.83% to 1.58% for DDT and zero to 8.54% for permethrin. Mosquitoes collected in Nangbéto displayed 81.53% mortality with deltamethrin. An. coluzzii and An. gambiae s.s were found in sympatry in Nangbéto and Mango . The allelic frequency of L1014F was high, ranging from 66 to 100% in both An. coluzzii and An. gambiae s.s. For the first time we detected the L1014S allele in both An. coluzzii and An. gambiaes.s. from Togo at the frequency ranging from 5% to 13% in all the sites. The kdr N1575Y was present at various frequencies in both species ranging from 10% to 45%. Both An. gambiae s.s. and An. coluzzii shared the ace1 R mutation in all investigated sites with allelic frequency ranging from 4% to 16%. Conclusion: These results showed that multiple mutations are involved in insecticides resistance in An. gambiae populations from Togo including the kdr L1014F, L1014S, and N1575Y and ace.1 R G119S mutations.
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Affiliation(s)
- Innocent Djègbè
- University of Sciences, Technologies and Mathematics, Ecole Normale Supérieure de Natitingou, Natitingou, BP 123, Benin
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Romaric Akoton
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, BP 526, Benin
| | - Genevieve Tchigossou
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Faculty of Sciences and Techniques, University of Abomey-Calavi, Cotonou, BP 526, Benin
| | | | - Seun Michael Atoyebi
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Razack Adéoti
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Francis Zeukeng
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
- Department of Biochemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, BP 812, Cameroon
| | - Guillaume Koffivi Ketoh
- Research unit of Ecotoxicology, Faculty of Sciences, University of Lomé, Lomé, 01 BP 1515 , Togo
| | - Rousseau Djouaka
- The AgroEcoHealth Platform, International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
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Camara S, Koffi AA, Ahoua Alou LP, Koffi K, Kabran JPK, Koné A, Koffi MF, N'Guessan R, Pennetier C. Mapping insecticide resistance in Anopheles gambiae (s.l.) from Côte d'Ivoire. Parasit Vectors 2018; 11:19. [PMID: 29310704 PMCID: PMC5759872 DOI: 10.1186/s13071-017-2546-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/21/2017] [Indexed: 11/10/2022] Open
Abstract
Background Insecticide resistance in malaria vectors is an increasing threat to vector control tools currently deployed in endemic countries. Resistance management must be an integral part of National Malaria Control Programmes’ (NMCPs) next strategic plans to alleviate the risk of control failure. This obviously will require a clear database on insecticide resistance to support the development of such a plan. The present work gathers original data on insecticide resistance between 2009 and 2015 across Côte d’Ivoire in West Africa. Methods Two approaches were adopted to build or update the resistance data in the country. Resistance monitoring was conducted between 2013 and 2015 in 35 sentinel sites across the country using the WHO standard procedure of susceptibility test on adult mosquitoes. Four insecticide families (pyrethroids, organochlorides, carbamates and organophosphates) were tested. In addition to this survey, we also reviewed the literature to assemble existing data on resistance between 2009 and 2015. Results High resistance levels to pyrethroids, organochlorides and carbamates were widespread in all study sites whereas some Anopheles populations remained susceptible to organophosphates. Three resistance mechanisms were identified, involving high allelic frequencies of kdr L1014F mutation (range = 0.46–1), relatively low frequencies of ace-1R (below 0.5) and elevated activity of insecticide detoxifying enzymes, mainly mixed function oxidases (MFO), esterase and glutathione S-transferase (GST) in almost all study sites. Conclusion This detailed map of resistance highlights the urgent need to develop new vector control tools to complement current long-lasting insecticidal nets (LLINs) although it is yet unclear whether these resistance mechanisms will impact malaria transmission control. Researchers, industry, WHO and stakeholders must urgently join forces to develop alternative tools. By then, NMCPs must strive to develop effective tactics or plans to manage resistance keeping in mind country-specific context and feasibility.
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Affiliation(s)
- Soromane Camara
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.,Université Félix Houphouët Boigny (UFHB), 22 BP 582, Abidjan 22, Côte d'Ivoire
| | - Alphonsine A Koffi
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.
| | - Ludovic P Ahoua Alou
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Kouakou Koffi
- Université Félix Houphouët Boigny (UFHB), 22 BP 582, Abidjan 22, Côte d'Ivoire
| | - Jean-Paul K Kabran
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Aboubacar Koné
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Mathieu F Koffi
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire
| | - Raphaël N'Guessan
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire.,London School of Hygiene and Tropical Medicine, London, UK
| | - Cédric Pennetier
- Institut Pierre Richet/Institut National de Santé Publique (IPR/INSP), BP 1500, Bouake, Côte d'Ivoire. .,Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Control (MIVEGEC), UMR 5290 CNRS-IRD-UM, Montpellier, France.
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20
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Liu QM, Li CX, Wu Q, Shi QM, Sun AJ, Zhang HD, Guo XX, Dong YD, Xing D, Zhang YM, Han Q, Diao XP, Zhao TY. Identification of Differentially Expressed Genes In Deltamethrin-Resistant Culex pipiens quinquefasciatus. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2017; 33:324-330. [PMID: 29369035 DOI: 10.2987/17-6658.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Culex quinquefasciatus is one of China's major house-dwelling mosquito species and an important vector of filariasis and encephalitis. Chemical treatments represent one of the most successful approaches for comprehensive mosquito prevention and control. However, the widespread use of chemical pesticides has led to the occurrence and development of insecticide resistance. Therefore, in-depth studies of resistance to insecticides are of vital importance. In this study, we performed a gene expression analysis to investigate genes from Cx. quinquefasciatus that may confer pyrethroid resistance. We aimed to understand the mechanisms of Cx. quinquefasciatus resistance to pyrethroid insecticides and provide insights into insect resistance management. Using a resistance bioassay, we determined the deltamethrin LC50 values (lethal concentration required to kill 50% of the population) for Cx. quinquefasciatus larvae in the F21, F23, F24, F26, F27, and F30 generations. The 7 tested strains exhibited pesticide resistance that was 25.25 to 87.83 times higher than that of the SanYa strain. Moreover, the expression of the OBPjj7a (odorant-binding protein OBPjj7a), OBP28 (odorant-binding protein OBP28), and E2 (ubiquitin-conjugating enzyme) genes was positively correlated with deltamethrin resistance ( R2 = 0.836, P = 0.011; R2 = 0.788, P = 0.018; and R2 = 0.850, P = 0.009, respectively) in Cx. quinquefasciatus. The expression of 4 additional genes, H/ACA, S19, SAR2, and PGRP, was not correlated with deltamethrin resistance. In summary, this study identified 3 Cx. quinquefasciatus genes with potential involvement in deltamethrin resistance, and these results may provide a theoretical basis for the control of mosquito resistance and insights into resistance detection.
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21
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WHO cone bio-assays of classical and new-generation long-lasting insecticidal nets call for innovative insecticides targeting the knock-down resistance mechanism in Benin. Malar J 2017; 16:77. [PMID: 28202024 PMCID: PMC5312429 DOI: 10.1186/s12936-017-1727-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/07/2017] [Indexed: 11/10/2022] Open
Abstract
Background To increase the effectiveness of insecticide-treated nets (ITN) in areas of high resistance, new long-lasting insecticidal nets (LLINs) called new-generation nets have been developed. These nets are treated with the piperonyl butoxide (PBO) synergist which inhibit the action of detoxification enzymes. The effectiveness of the new-generation nets has been proven in some studies, but their specific effect on mosquitoes carrying detoxification enzymes and those carrying both detoxification enzymes and the knock-down resistance gene in Benin is not well known. Thus, the objective of this study is to evaluate the efficacy of LLINs treated with PBO on multi-resistant Anopheles gambiae s.l. Methods The study occurred in seven cities in Benin, Abomey, Cotonou, Porto-Novo, Zangnanado, Parakou, Malanville and Tanguiéta, and included ten locations selected on a north–south transect. Mosquito larvae were collected from these sites, and adult females from these larvae were exposed to single-pyrethroid-treated nets (LifeNet, PermaNet 2.0, Olyset Net) and bi-treated nets (PermaNet 3.0 and Olyset Plus) based on their level of resistance and using WHO cone tests following WHO guidelines. Results The different LLINs showed 100% mortality of the susceptible laboratory strain Kisumu and the resistant strain Ace-1R Kisumu. However, with the resistant laboratory strain kdr-Kisumu, mortality was low (16–32%) for all LLINs except PermaNet 3.0 (82.9%). The mortality of local strains carrying only the kdr mechanism varied from 0 to 47% for the single-pyrethroid-treated LLINs and 9 to 86% for bi-treated LLINs. With local strains carrying several mechanisms of resistance (kdr + detoxification enzymes), the observed mortality with different LLINs was also low except for PermaNet 3.0, which induced significantly higher mortality, usually greater than 75% (p < 0.001), with multi-resistant strains. The inhibition of the mortalities induced by the LLINs (11–96%) on multi-resistant field populations was similar to the inhibition observed with the laboratory strain carrying only the knock-down resistance mechanism (kdr-Kisumu) (p > 0.05). Conclusion This study showed that the new-generation LLINs treated with pyrethroids and PBO showed better efficacy compared to conventional LLINs. Although the addition of PBO significantly increased the mortality of mosquitoes, the significant role of the kdr resistance gene in the low efficacy of LLINs calls for LLIN technology innovation that specifically targets this mechanism.
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22
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Noukpo MH, Damien GB, Elanga-N'Dille E, Sagna AB, Drame PM, Chaffa E, Boussari O, Corbel V, Akogbéto M, Remoue F. Operational Assessment of Long-Lasting Insecticidal Nets by Using an Anopheles Salivary Biomarker of Human-Vector Contact. Am J Trop Med Hyg 2016; 95:1376-1382. [PMID: 27928087 DOI: 10.4269/ajtmh.15-0541] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/19/2016] [Indexed: 01/10/2023] Open
Abstract
The widespread implementation of long-lasting insecticidal nets (LLINs) is a major intervention method for malaria control. Although the LLINs coverage increases, information available on the physical integrity (PI) of implemented LLINs is incomplete. This study aimed to validate human IgG antibody (Ab) response to Anopheles gSG6-P1 salivary peptide antigen, previously demonstrated as a pertinent biomarker of human exposure to Anopheles bites, for evaluating the PI of LLINs in field conditions. We analyzed data from 262 randomly selected children (< 5 years of age) in health districts of Benin. Anti-gSG6-P1 IgG responses were assessed and compared with the PI of LLINs that these same children slept under, and evaluated by the hole index (HI). Specific IgG levels were positively correlated to LLINs HI (r = 0.342; P < 0.0001). According to antipeptide IgG level (i.e., intensity of vector exposure), two categories of LLINs PI were defined: 1) group "HI: [0, 100]" corresponding to LLINs with "good" PI and 2) "HI > 100" corresponding to LLINs with "bad" PI. These results suggest that human Ab response to salivary peptide could be a complementary tool to help defining a standardized threshold of efficacy for LLINs under field use.
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Affiliation(s)
- Mahoutin H Noukpo
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.,UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin
| | - Georgia B Damien
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.,UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin
| | - Emmanuel Elanga-N'Dille
- UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin
| | - André B Sagna
- Institut Pierre Richet (IPR), Institut Nationale de la Santé Publique (INSP), Bouaké, Côte d'Ivoire
| | - Papa M Drame
- UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin
| | - Evelyne Chaffa
- Programme National de Lutte Contre le Paludisme (PNLP), Ministère de la Santé, Cotonou, Bénin
| | - Olayidé Boussari
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.,UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin
| | - Vincent Corbel
- UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin.,Department of Entomology, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom, Thailand
| | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin.,Faculté des Sciences et Techniques (FAST), Université d'Abomey Calavi (UAC), Abomey, Bénin
| | - Franck Remoue
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin. .,UMR IRD 224-CNRS 5290-Universités Montpellier Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Cotonou, Bénin.,Institut Pierre Richet (IPR), Institut Nationale de la Santé Publique (INSP), Bouaké, Côte d'Ivoire
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23
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Djouaka R, Riveron JM, Yessoufou A, Tchigossou G, Akoton R, Irving H, Djegbe I, Moutairou K, Adeoti R, Tamò M, Manyong V, Wondji CS. Multiple insecticide resistance in an infected population of the malaria vector Anopheles funestus in Benin. Parasit Vectors 2016; 9:453. [PMID: 27531125 PMCID: PMC4987972 DOI: 10.1186/s13071-016-1723-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 07/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background Knowledge on the spread and distribution of insecticide resistance in major malaria vectors such as Anopheles funestus is key to implement successful resistance management strategies across Africa. Here, by assessing the susceptibility status of an inland population of An. funestus Giles (Kpome) and investigating molecular basis of resistance, we show that multiple resistance and consistent plasmodium infection rate are present in Anopheles funestus populations from Kpome. Methods The insecticide susceptibility level of collected Anopheles funestus was assessed. Synergist (PBO) was used to screen resistance mechanisms. The TaqMan technique was used for genotyping of insecticide resistant alleles and detecting plasmodium infection levels. The nested PCR was used to further assess the plasmodium infection rate. Results The TaqMan analysis of plasmodial infections revealed an infection rate (18.2 %) of An. funestus in this locality. The WHO bioassays revealed a multiple phenotypic resistance profile for An. funestus in Kpome. This population is highly resistant to pyrethroids (permethrin and deltamethrin), organochlorines (DDT), and carbamates (bendiocarb). A reduced susceptibility was observed with dieldrin. Mortalities did not vary after pre-exposure to PBO for DDT indicating that cytochrome P450s play little role in DDT resistance in Kpome. In contrast, we noticed, a significant increase in mortalities when PBO was combined to permethrin suggesting the direct involvement of P450s in pyrethroid resistance. A high frequency of the L119F-GSTe2 DDT resistance marker was observed in the wild DDT resistant population (9 %RS and 91 %RR) whereas the A296S mutation was detected at a low frequency (1 %RS and 99 %SS). Conclusion The presence of multiple resistance in An. funestus populations in the inland locality of Kpome is established in this study as recently documented in the costal locality of Pahou. Data from both localities suggest that resistance could be widespread in Benin and this highlights the need for further studies to assess the geographical distribution of insecticide resistance across Benin and neighboring countries as well as a more comprehensive analysis of the resistance mechanisms involved. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1723-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rousseau Djouaka
- International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin.
| | - Jacob M Riveron
- Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
| | | | - Genevieve Tchigossou
- International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin.,University of Abomey, Calavi BP 526, Cotonou, Benin
| | - Romaric Akoton
- International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin.,University of Abomey, Calavi BP 526, Cotonou, Benin
| | - Helen Irving
- Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
| | - Innocent Djegbe
- University of Sciences, Arts and Techniques of Natitingou, Ecole Normale Supérieure de Natitingou, Natitingou, BP 123, Benin
| | | | - Razack Adeoti
- International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Manuele Tamò
- International Institute of Tropical Agriculture, Cotonou, 08 BP 0932, Benin
| | - Victor Manyong
- International Institute of Tropical Agriculture, Dar Es Salaam, Tanzania
| | - Charles S Wondji
- Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK
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Luc DS, Benoit A, Laurette D, Michel M. Indirect evidence that agricultural pesticides select for insecticide resistance in the malaria vector Anopheles gambiae. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2016; 41:34-40. [PMID: 27232122 DOI: 10.1111/jvec.12191] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/25/2015] [Indexed: 06/05/2023]
Abstract
We investigated the possible relationship between the agricultural use of insecticides and the emergence of insecticide resistance. Bioassays were conducted using simulated mosquito larval habitats and well known Anopheles gambiae strains. Soil samples were collected from vegetable production areas in Benin, including one site with insecticide use, one site where insecticides had not been used for two months, and a third where insecticides had not been used. Pupation and emergence rates were very low in pyrethroid-susceptible strains when exposed to soil that had been recently exposed to insecticides. Pupation and emergence rates in strains with the kdr mutation alone or both the kdr and Ace-1 mutations were much higher. Overall, strains with the kdr mutation survived at higher rates compared to that without kdr mutation. Although this study is observational, we provide indirect evidence indicating that soils from agricultural areas contain insecticide residues that can play a role in the emergence of insecticide resistance in Anopheles. This aspect should be taken into account to better utilize the insecticide in the context of integrated pest management programs.
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Affiliation(s)
- Djogbénou S Luc
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918 Cotonou, Bénin.
| | - Assogba Benoit
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918 Cotonou, Bénin
| | - Djossou Laurette
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918 Cotonou, Bénin
| | - Makoutode Michel
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918 Cotonou, Bénin
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An ace-1 gene duplication resorbs the fitness cost associated with resistance in Anopheles gambiae, the main malaria mosquito. Sci Rep 2015; 5:14529. [PMID: 26434951 PMCID: PMC4592963 DOI: 10.1038/srep14529] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/25/2015] [Indexed: 11/08/2022] Open
Abstract
Widespread resistance to pyrethroids threatens malaria control in Africa. Consequently, several countries switched to carbamates and organophophates insecticides for indoor residual spraying. However, a mutation in the ace-1 gene conferring resistance to these compounds (ace-1(R) allele), is already present. Furthermore, a duplicated allele (ace-1(D)) recently appeared; characterizing its selective advantage is mandatory to evaluate the threat. Our data revealed that a unique duplication event, pairing a susceptible and a resistant copy of the ace-1 gene spread through West Africa. Further investigations revealed that, while ace-1(D) confers less resistance than ace-1(R), the high fitness cost associated with ace-1(R) is almost completely suppressed by the duplication for all traits studied. ace-1 duplication thus represents a permanent heterozygote phenotype, selected, and thus spreading, due to the mosaic nature of mosquito control. It provides malaria mosquito with a new evolutionary path that could hamper resistance management.
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Akogbéto MC, Aïkpon RY, Azondékon R, Padonou GG, Ossè RA, Agossa FR, Beach R, Sèzonlin M. Six years of experience in entomological surveillance of indoor residual spraying against malaria transmission in Benin: lessons learned, challenges and outlooks. Malar J 2015; 14:242. [PMID: 26063497 PMCID: PMC4465467 DOI: 10.1186/s12936-015-0757-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/02/2015] [Indexed: 11/23/2022] Open
Abstract
Background From 2008 to 2013, a prevention intervention against malaria based on indoor residual spraying (IRS) was implemented in Benin. From 2008 to 2012, Ficam M®, a bendiocarb-containing product was used for house spraying, in association with pirimiphos methyl EC (Actellic EC) in 2013. This operation aimed to strengthen the effectiveness of treated nets so as to expedite the achievement of Millennium Development Goals (MDGs): the reduction of morbidity and mortality due to malaria by 75 % from 2000 to 2015. Methods Monitoring and evaluation (M&E) was implemented in order to evaluate the impact of IRS intervention on malaria transmission. Anopheles gambiae s.l. populations were sampled by human landing catch. In addition, window exit traps and pyrethrum spray catches were performed to assess exophagic behaviour of Anopheles vectors the main malaria vector in the treated areas. The residual activity of insecticide in the treated walls was also assessed using WHO bioassay test. Results The purpose of this project was to draw attention to new challenges and future prospects for the success of IRS in Benin. The main strength of the intervention was a large-scale operation in which more than 80 % of the houses were treated due to the strong adhesion of population. In addition, a significant reduction of the EIR in areas under IRS were observed. However, there were many challenges including the high cost of IRS implementation and the identification of suitable areas to implement IRS. This was because of the low and short residual effect of the insecticides recommended for IRS and the management strategy for vector resistance to insecticides. This indicated that challenges are accompanied by suggested solutions. For the cost of IRS to be accessible to states, then local organizations need to be created in partnership with the National Malaria Control Programme (NMCP) in order to ensure relevant planning and implementation of IRS. Conclusion As an anticipatory measure against vector resistance, this paper proposes various methods, such as periodic IRS based on a combination of two or three insecticides of different classes used in rotation every two or three years.
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Affiliation(s)
- Martin C Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Faculté des Sciences et Techniques, Université d'Abomey Calavi, Cotonou, Bénin.
| | - Rock Y Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Faculté des Sciences et Techniques, Université d'Abomey Calavi, Cotonou, Bénin.
| | - Roseric Azondékon
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Université du Massachusetts Amherst, Amherst, MA, USA.
| | - Gil G Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Faculté des Sciences et Techniques, Université d'Abomey Calavi, Cotonou, Bénin.
| | - Razaki A Ossè
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Université d'Agriculture de Kétou, Kétou, Benin.
| | - Fiacre R Agossa
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin. .,Faculté des Sciences et Techniques, Université d'Abomey Calavi, Cotonou, Bénin.
| | | | - Michel Sèzonlin
- Faculté des Sciences et Techniques, Université d'Abomey Calavi, Cotonou, Bénin.
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Scott JG, Yoshimizu MH, Kasai S. Pyrethroid resistance in Culex pipiens mosquitoes. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 120:68-76. [PMID: 25987223 DOI: 10.1016/j.pestbp.2014.12.018] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/13/2014] [Accepted: 12/15/2014] [Indexed: 06/04/2023]
Abstract
Mosquitoes within the Culex pipiens complex are widely distributed and important in the transmission of many human diseases. Insecticides, pyrethroids in particular, remain a mainstay for control of these important vectors. In this paper we review what is known about the levels, mechanisms and fitness costs of pyrethroid resistance in Cx. pipiens. Pyrethroid resistance in Cx. pipiens is a global problem, and resistance ratios of up to 7000-fold have been found in larvae of field collected mosquitoes. However, there is considerable variation between populations, indicating significant geographic heterogeneity of the resistance. The two major mechanisms of resistance to pyrethroids in Culex are mutations in Vssc (target site insensitivity) and overexpression of cytochrome P450(s) (increased detoxification). The most frequently reported Vssc mutation is L1014F (i.e. kdr), which has been found throughout the world. The L1014S mutation has been found in Cx. p. pallens from Japan and China, and in Cx. p. pipiens from China. The L1014C mutation has only been reported for Cx. p. pipens molestus from China and the V1016G mutation has only been reported from Saudi Arabia. Studies on the P450s of Cx. pipiens have identified several that are overexpressed (measured as transcript levels) in pyrethroid resistant strains. CYP9M10 is consistently overexpressed in pyrethroid resistant Cx. pipiens from at least seven countries, suggesting this P450 might be of global importance in resistance. Both CYP9M10-mediated pyrethroid resistance and kdr have fitness costs in the absence of insecticides under certain environmental conditions. Research needs and future directions are discussed.
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Affiliation(s)
- Jeffrey G Scott
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, USA.
| | - Melissa Hardstone Yoshimizu
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, USA; California Department of Public Health, Vector-Borne Disease Section, 850 Marina Bay Pkwy, Richmond, California, USA
| | - Shinji Kasai
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, USA; Department of Medical Entomology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjukuku, Tokyo, Japan
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Gnanguenon V, Agossa FR, Badirou K, Govoetchan R, Anagonou R, Oke-Agbo F, Azondekon R, AgbanrinYoussouf R, Attolou R, Tokponnon FT, Aïkpon R, Ossè R, Akogbeto MC. Malaria vectors resistance to insecticides in Benin: current trends and mechanisms involved. Parasit Vectors 2015; 8:223. [PMID: 25886599 PMCID: PMC4395909 DOI: 10.1186/s13071-015-0833-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/29/2015] [Indexed: 11/29/2022] Open
Abstract
Background Insecticides are widely used to control malaria vectors and have significantly contributed to the reduction of malaria-caused mortality. In addition, the same classes of insecticides were widely introduced and used in agriculture in Benin since 1980s. These factors probably contributed to the selection of insecticide resistance in malaria vector populations reported in several localities in Benin. This insecticide resistance represents a threat to vector control tool and should be monitored. The present study reveals observed insecticide resistance trends in Benin to help for a better management of insecticide resistance. Methods Mosquito larvae were collected in eight sites and reared in laboratory. Bioassays were conducted on the adult mosquitoes upon the four types of insecticide currently used in public health in Benin. Knock-down resistance, insensitive acetylcholinesterase-1 resistance, and metabolic resistance analysis were performed in the mosquito populations based on molecular and biochemical analysis. The data were mapped using Geographical Information Systems (GIS) with Arcgis software. Results Mortalities observed with Deltamethrin (pyrethroid class) were less than 90% in 5 locations, between 90-97% in 2 locations, and over 98% in one location. Bendiocarb (carbamate class) showed mortalities ranged 90-97% in 2 locations and were over 98% in the others locations. A complete susceptibility to Pirimiphos methyl and Fenitrothion (organophosphate class) was observed in all locations with 98-100% mortalities. Knock-down resistance frequencies were high (0.78-0.96) and similar between Anopheles coluzzii, Anopheles gambiae, Anopheles arabiensis, and Anopheles melas. Insensitive acetylcholinesterase-1 was rare (0.002-0.1) and only detected in Anopheles gambiae in concomitance with Knock-down resistance mutation. The maps showed a large distribution of Deltamethrin resistance, Knock-down mutation and metabolic resistance throughout the country, a suspected resistance to Bendiocarb and detection of insensitive acetylcholinesterase-1 from northern Benin, and a wide distribution of susceptible vectors to Pirimiphos methyl and Fenitrothion. Conclusion This study showed a widespread resistance of malaria vectors to pyrethroid previously located in southern Benin, an early emergence of carbamates resistance from northern Benin and a full susceptibility to organophosphates. Several resistance mechanisms were detected in vectors with a potential cross resistance to pyrethroids through Knock-down and metabolic resistance mechanisms.
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Affiliation(s)
- Virgile Gnanguenon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Fiacre R Agossa
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Kefilath Badirou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Renaud Govoetchan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Rodrigue Anagonou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Fredéric Oke-Agbo
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
| | - Roseric Azondekon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
| | - Ramziath AgbanrinYoussouf
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Roseline Attolou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | | | - Rock Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
| | - Razaki Ossè
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Université d'Agriculture de Kétou, Kétou, Benin.
| | - Martin C Akogbeto
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin.
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Tene Fossog B, Ayala D, Acevedo P, Kengne P, Ngomo Abeso Mebuy I, Makanga B, Magnus J, Awono-Ambene P, Njiokou F, Pombi M, Antonio-Nkondjio C, Paupy C, Besansky NJ, Costantini C. Habitat segregation and ecological character displacement in cryptic African malaria mosquitoes. Evol Appl 2015; 8:326-45. [PMID: 25926878 PMCID: PMC4408144 DOI: 10.1111/eva.12242] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 12/08/2014] [Indexed: 01/09/2023] Open
Abstract
Understanding how divergent selection generates adaptive phenotypic and population diversification provides a mechanistic explanation of speciation in recently separated species pairs. Towards this goal, we sought ecological gradients of divergence between the cryptic malaria vectors Anopheles coluzzii and An. gambiae and then looked for a physiological trait that may underlie such divergence. Using a large set of occurrence records and eco-geographic information, we built a distribution model to predict the predominance of the two species across their range of sympatry. Our model predicts two novel gradients along which the species segregate: distance from the coastline and altitude. Anopheles coluzzii showed a ‘bimodal’ distribution, predominating in xeric West African savannas and along the western coastal fringe of Africa. To test whether differences in salinity tolerance underlie this habitat segregation, we assessed the acute dose–mortality response to salinity of thirty-two larval populations from Central Africa. In agreement with its coastal predominance, Anopheles coluzzii was overall more tolerant than An. gambiae. Salinity tolerance of both species, however, converged in urban localities, presumably reflecting an adaptive response to osmotic stress from anthropogenic pollutants. When comparing degree of tolerance in conjunction with levels of syntopy, we found evidence of character displacement in this trait.
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Affiliation(s)
- Billy Tene Fossog
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon ; Department of Animal Biology, Faculty of Sciences, University of Yaoundé I Yaoundé, Cameroon
| | - Diego Ayala
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Eck Institute for Global Health & Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Pelayo Acevedo
- SaBio, Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM Ciudad Real, Spain
| | - Pierre Kengne
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | | | - Boris Makanga
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon ; Institut de Recherche en Ecologie Tropicale (IRET) Libreville, Gabon
| | - Julie Magnus
- Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | - Flobert Njiokou
- Department of Animal Biology, Faculty of Sciences, University of Yaoundé I Yaoundé, Cameroon
| | - Marco Pombi
- Sezione di Parassitologia, Dipartimento di Sanità Pubblica e Malattie Infettive, Università di Roma 'La Sapienza' Rome, Italy
| | - Christophe Antonio-Nkondjio
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
| | - Christophe Paupy
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Centre International de Recherches Médicales de Franceville (CIRMF) Franceville, Gabon
| | - Nora J Besansky
- Eck Institute for Global Health & Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA
| | - Carlo Costantini
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1, UM2, CNRS 5290, IRD 224) Montpellier, France ; Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) Yaoundé, Cameroon
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Assogba BS, Djogbénou LS, Saizonou J, Milesi P, Djossou L, Djegbe I, Oumbouke WA, Chandre F, Baba-Moussa L, Weill M, Makoutodé M. Phenotypic effects of concomitant insensitive acetylcholinesterase (ace-1(R)) and knockdown resistance (kdr(R)) in Anopheles gambiae: a hindrance for insecticide resistance management for malaria vector control. Parasit Vectors 2014; 7:548. [PMID: 25471264 PMCID: PMC4265331 DOI: 10.1186/s13071-014-0548-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 11/19/2014] [Indexed: 01/29/2023] Open
Abstract
Background Malaria is endemic in sub-Saharan Africa with considerable burden for human health. Major insecticide resistance mechanisms such as kdrR and ace-1Ralleles constitute a hindrance to malaria vector control programs. Anopheles gambiae bearing both kdr and ace-1 resistant alleles are increasingly recorded in wild populations. In order to maintain the efficacy of vector control strategies, the characterization of concomitant kdr and ace-1 resistance, and their pleiotropic effects on malaria vector phenotype on insecticide efficacy are important. Methods Larval and adult bioassays were performed with different insecticide classes used in public health following WHO standard guidelines on four laboratory Anopheles gambiae strains, sharing the same genetic background but harboring distinct resistance status: KISUMU with no resistance allele; ACERKIS with ace-1R allele; KISKDR with kdrR allele and ACERKDRKIS with both resistance alleles’ ace-1R and kdrR. Results Larval bioassays indicate that the homozygote resistant strain harboring both alleles (ACERKDRKIS) displayed slightly but significantly higher resistance level to various insecticides like carbamates (bendiocarb, p < 0.001; propoxur, p = 0.02) and organophosphates (chlorpyriphos-methyl, p = 0.002; fenitrothion, p < 0.001) when compared to ACERKIS strain. However, no differences were recorded between ACERKDRKIS and KISKDR resistance level against permethrin (Pyrethroid, p = 0.7) and DDT (Organochlorine, p = 0.24). For adult bioassays, the percentages of mosquitoes knocked down were significantly lower for ACERKDRKIS than for KISKDR with permethrin (p = 0.003) but not with deltamethrin. The percentage of mortality from adult bioassays was similar between ACERKDRKIS and ACERKIS with carbamates and organophosphates, or between ACERKDRKIS and KISKDR with pyrethroid and DDT. Concerning acetylcholinesterase enzyme, ACERKDRKIS strain showed similarAChE1 activity than that of ACERKIS. Conclusion The presence of both kdrR and ace-1R alleles seems to increase the resistance levels to both carbamate and organophosphate insecticides and at operational level, may represent an important threat to malaria vector control programs in West Africa.
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Affiliation(s)
- Benoît S Assogba
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918, Cotonou, Benin. .,Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS-UM2-IRD), Université Montpellier 2, Montpellier, France.
| | - Luc S Djogbénou
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918, Cotonou, Benin.
| | - Jacques Saizonou
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918, Cotonou, Benin.
| | - Pascal Milesi
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS-UM2-IRD), Université Montpellier 2, Montpellier, France.
| | - Laurette Djossou
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918, Cotonou, Benin.
| | - Innocent Djegbe
- Institut de Recherche pour le Développement (IRD), MIVEGEC (UMR 224-CNRS 5290-UM1-UM2), Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.
| | - Welbeck A Oumbouke
- Centre de Recherche Entomologique de Cotonou (CREC), Health Ministry, Cotonou, Bénin.
| | - Fabrice Chandre
- Institut de recherche pour le développement, Unité Mixte de Recherche MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), Montpellier, France.
| | - Lamine Baba-Moussa
- Faculté des Sciences et Techniques, Laboratoire de Biologie et de Typage Moléculaire en Microbiologie, Université d'Abomey Calavi, 05 BP 1604, Cotonou, Benin.
| | - Mylene Weill
- Institut des Sciences de l'Evolution de Montpellier (UMR 5554, CNRS-UM2-IRD), Université Montpellier 2, Montpellier, France.
| | - Michel Makoutodé
- Institut Régional de Santé Publique, Université d'Abomey Calavi, 01BP918, Cotonou, Benin.
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Lukwa N, Sande S, Makuwaza A, Chiwade T, Netsa M, Asamoa K, Vazquez-Prokopec G, Reithinger R, Williams J. Nationwide assessment of insecticide susceptibility in Anopheles gambiae populations from Zimbabwe. Malar J 2014; 13:408. [PMID: 25322726 PMCID: PMC4210579 DOI: 10.1186/1475-2875-13-408] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/08/2014] [Indexed: 11/14/2022] Open
Abstract
Background The scale-up of malaria interventions in sub-Saharan Africa has been accompanied by a dramatic increase in insecticide resistance in Anopheles spp. In Zimbabwe resistance to pyrethroid insecticides was reported in Gokwe District in 2008. This study reports results of the first nation-wide assessment of insecticide susceptibility in wild populations of Anopheles gambiae sensu lato (s.l.) in Zimbabwe, and provides a comprehensive review of the insecticide resistance status of An. gambiae s.l. in southern African countries. Methods World Health Organization (WHO) insecticide susceptibility tests were performed on 2,568 field collected mosquitoes originating from 13 sentinel sites covering all endemic regions in Zimbabwe in 2011–2012. At each site, 24-hour mortality and knock-down values for 50% and 90% of exposed mosquitoes (KD50 and KD90, respectively) were calculated for pools of 20–84 (mean, 54) mosquitoes exposed to 4% DDT, 0.1% bendiocarb, 0.05% λ-cyhalothrin or 5% malathion. Susceptibility results from Zimbabwe were compiled with results published during 2002–2012 for all southern African countries to investigate the resistance status of An. gambiae s.l. in the region. Results Using WHO criteria, insecticide resistance was not detected at any site sampled and for any of the insecticide formulations tested during the malaria transmission season in 2012. Knock-down within 1 hr post-insecticide exposure ranged from 95% to 100%; mortality 24 hours post-insecticide exposure ranged from 98% to 100%. Despite the lack of insecticide resistance, high variability was found across sites in KD50 and KD90 values. A total of 24 out of 64 (37.5%) sites in southern Africa with reported data had evidence of phenotypic insecticide resistance in An. gambiae s.l. to at least one insecticide. Conclusion Despite a long history of indoor residual spraying of households with insecticide, up to 2012 there was no evidence of phenotypic resistance to any of the four insecticide classes in An. gambiae s.l. collected across different eco-epidemiological areas in Zimbabwe. Results reinforce the need for careful monitoring over time in sentinel sites in order to detect the potential emergence and propagation of insecticide resistance as insecticidal vector control interventions in Zimbabwe continue to be implemented. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-408) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | - Richard Reithinger
- Global Health Division, International Development Group, RTI International, Suite 750, 701 13th Street, Washington D,C, 20005, USA.
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Ngufor C, Chouaïbou M, Tchicaya E, Loukou B, Kesse N, N'Guessan R, Johnson P, Koudou B, Rowland M. Combining organophosphate-treated wall linings and long-lasting insecticidal nets fails to provide additional control over long-lasting insecticidal nets alone against multiple insecticide-resistant Anopheles gambiae in Côte d'Ivoire: an experimental hut trial. Malar J 2014; 13:396. [PMID: 25301219 PMCID: PMC4203900 DOI: 10.1186/1475-2875-13-396] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/27/2014] [Indexed: 11/15/2022] Open
Abstract
Background Insecticide-treated wall lining (ITWL) is a new concept in malaria vector control. Some Anopheles gambiae populations in West Africa have developed resistance to all the main classes of insecticides. It needs to be demonstrated whether vector control can be improved or resistance managed when non-pyrethroid ITWL is used alone or together with long-lasting insecticidal nets (LLINs) against multiple insecticide-resistant vector populations. Methods Two experimental hut trials were carried out as proofs of concept to evaluate pirimiphos methyl (p-methyl)-treated plastic wall lining (WL) and net wall hangings (NWH) used alone and in combination with LLINs against multiple insecticide-resistant An. gambiae in Tiassalé, Côte d’Ivoire. Comparison was made to commercial deltamethrin WL and genotypes for kdr and ace-1R resistance were monitored. Results The kdr and ace-1R allele frequencies were 0.83 and 0.44, respectively. Anopheles gambiae surviving discriminating concentrations of deltamethrin and p-methyl in WHO resistance tests were 57 and 96%, respectively. Mortality of free-flying An. gambiae in huts with p-methyl WL and NWH (66 and 50%, respectively) was higher than with pyrethroid WL (32%; P < 0.001). Mortality with LLIN was 63%. Mortality with the combination of LLIN plus p-methyl NWH (61%) or LLIN plus p-methyl WL (73%) did not significantly improve upon the LLIN alone or p-methyl WL or NWH alone. Mosquitoes bearing the ace-1R were more likely to survive exposure to p-methyl WL and NWH. Selection of heterozygote and homozygote ace-1R or kdr genotypes was not less likely after exposure to combined LLIN and p-methyl treatments than to single p-methyl treatment. Blood-feeding rates were lower in huts with the pyrethroid LLIN (19%) than with p-methyl WL (72%) or NWH (76%); only LLIN contributed to personal protection. Conclusions Combining p-methyl WL or NWH with LLINs provided no improvement in An. gambiae control or personal protection over LLIN alone in southern Côte d’Ivoire; neither did the combination manage resistance. Additional resistance mechanisms to kdr and ace-1R probably contributed to the survival of pyrethroid and organophophate-resistant mosquitoes. The study demonstrates the challenge that malaria control programmes will face if resistance to multiple insecticides continues to spread.
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Affiliation(s)
- Corine Ngufor
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
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Aïzoun N, Aïkpon R, Akogbéto M. Evidence of increasing L1014F kdr mutation frequency in Anopheles gambiae s.l. pyrethroid resistant following a nationwide distribution of LLINs by the Beninese National Malaria Control Programme. Asian Pac J Trop Biomed 2014; 4:239-43. [PMID: 25182444 DOI: 10.1016/s2221-1691(14)60238-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 01/20/2014] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE To determine the susceptibility status to pyrethroid in Anopheles gambiae s.l. (An. gambiae), the distribution of kdr "Leu-Phe" mutation in malaria vectors in Benin and to compare the current frequency of kdr "Leu-Phe" mutation to the previous frequency after long-lasting insecticide treated nets implementation. METHODS Larvae and pupae of An. gambiae s.l. mosquitoes were collected from the breeding sites in Littoral, Zou, Borgou and Alibori provinces. CDC susceptibility tests were conducted on unfed females mosquitoes aged 2-5 d old. An. gambiae mosquitoes were identified to species using PCR techniques. Molecular assays were also carried out to identify kdr mutations in individual mosquitoes. RESULTS The results showed that An. gambiae Malanville and Suru-lere populations were resistant to deltamethrin. Regarding An. gambiae Parakou and Bohicon populations, they were resistant to permethrin. PCR revealed 100% of mosquitoes tested were An. gambiae s.s. The L1014F kdr mutation was found in An. gambiae s.s. Malanville and Parakou at various allelic frequencies. The increase of kdr allelic frequency was positively correlated with CDC bioassays data. CONCLUSIONS : Pyrethroid resistance is widespread in malaria vector in Benin and kdr mutation is the main resistance mechanism involved. More attention may be paid for the future success of malaria control programmes based on LLINs with pyrethroids in the country.
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Affiliation(s)
- Nazaire Aïzoun
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin ; Faculté des Sciences et Techniques, Université d'Abomey Calavi, Calavi, Bénin
| | - Rock Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin ; Faculté des Sciences et Techniques, Université d'Abomey Calavi, Calavi, Bénin
| | - Martin Akogbéto
- Centre de Recherche Entomologique de Cotonou (CREC), 06 BP 2604, Cotonou, Bénin ; Faculté des Sciences et Techniques, Université d'Abomey Calavi, Calavi, Bénin
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Dantas-Torres F, Cameron MM, Colwell DD, Otranto D. A look into the Medical and Veterinary Entomology crystal ball. MEDICAL AND VETERINARY ENTOMOLOGY 2014; 28 Suppl 1:6-13. [PMID: 25171603 DOI: 10.1111/mve.12066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology.
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Affiliation(s)
- F Dantas-Torres
- Department of Immunology, Aggeu Magalhães Research Centre, Oswaldo Cruz Foundation, Recife, PE, Brazil; Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy
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Thomsen EK, Strode C, Hemmings K, Hughes AJ, Chanda E, Musapa M, Kamuliwo M, Phiri FN, Muzia L, Chanda J, Kandyata A, Chirwa B, Poer K, Hemingway J, Wondji CS, Ranson H, Coleman M. Underpinning sustainable vector control through informed insecticide resistance management. PLoS One 2014; 9:e99822. [PMID: 24932861 PMCID: PMC4059741 DOI: 10.1371/journal.pone.0099822] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/19/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination. Zambia's programme reported high levels of resistance to the insecticides it used in 2010, and, as a result, increased its investment in resistance monitoring to support informed resistance management decisions. METHODOLOGY/PRINCIPAL FINDINGS A country-wide survey on insecticide resistance in Zambian malaria vectors was performed using WHO bioassays to detect resistant phenotypes. Molecular techniques were used to detect target-site mutations and microarray to detect metabolic resistance mechanisms. Anopheles gambiae s.s. was resistant to pyrethroids, DDT and carbamates, with potential organophosphate resistance in one population. The resistant phenotypes were conferred by both target-site and metabolic mechanisms. Anopheles funestus s.s. was largely resistant to pyrethroids and carbamates, with potential resistance to DDT in two locations. The resistant phenotypes were conferred by elevated levels of cytochrome p450s. CONCLUSIONS/SIGNIFICANCE Currently, the Zambia National Malaria Control Centre is using these results to inform their vector control strategy. The methods employed here can serve as a template to all malaria-endemic countries striving to create a sustainable insecticide resistance management plan.
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Affiliation(s)
- Edward K. Thomsen
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Clare Strode
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Kay Hemmings
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Angela J. Hughes
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Mulenga Musapa
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | | | | | - Lucy Muzia
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | | | | | - Brian Chirwa
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | - Kathleen Poer
- Zambia Integrated Systems Strengthening Program, Abt Associates, Lusaka, Zambia
| | - Janet Hemingway
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Charles S. Wondji
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hilary Ranson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michael Coleman
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Ngufor C, Tchicaya E, Koudou B, N'Fale S, Dabire R, Johnson P, Ranson H, Rowland M. Combining organophosphate treated wall linings and long-lasting insecticidal nets for improved control of pyrethroid resistant Anopheles gambiae. PLoS One 2014; 9:e83897. [PMID: 24409286 PMCID: PMC3883662 DOI: 10.1371/journal.pone.0083897] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 11/10/2013] [Indexed: 11/18/2022] Open
Abstract
Background New approaches to delivering insecticides need to be developed to improve malaria vector control. Insecticidal durable wall lining (DL) and net wall hangings (NWH) are novel alternatives to indoor residual spraying which can be produced in a long-lasting format. Non-pyrethroid versions could be used in combination with long-lasting insecticidal nets for improved control and management of insecticide resistant vector populations. Methods Experimental hut trials were carried out in Valley du Kou, Burkina Faso to evaluate the efficacy of pirimiphos methyl treated DL and NWH either alone or in combination with LLINs against pyrethroid resistant Anopheles gambiae ss. Comparison was made with pyrethroid DL. Mosquitoes were genotyped for kdr and ace-1R resistant genes to investigate the insecticide resistance management potential of the combination. Results The overall kdr and ace-1R allele frequencies were 0.95 and 0.01 respectively. Mortality with p-methyl DL and NWH alone was higher than with pyrethroid DL alone (>95% vs 40%; P<0.001). Combining pyrethroid DL with LLINs did not show improvement in mortality (48%) compared to the LLIN alone (44%) (P>0.1). Combining p-methyl DL or NWH with LLINs reduced biting rates significantly (8–9%) compared to p-methyl DL and NWH alone (>40%) and killed all An gambiae that entered the huts. Mosquitoes bearing the ace-1R gene were more likely to survive in huts with p-methyl DL alone (p<0.03) whereas all resistant and susceptible genotypes were killed by the combination. Conclusion P-methyl DL and NWH outperformed pyrethroid DL. Combining p-methyl DL and NWH with LLINs could provide significant epidemiological benefits against a vector population which is resistant to pyrethroids but susceptible to organophosphates. There was evidence that the single intervention would select kdr and ace-1R resistance genes and the combination intervention might select less strongly. Technology to bind organophosphates to plastic wall lining would be worth developing.
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Affiliation(s)
- Corine Ngufor
- London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Emile Tchicaya
- Centre Suisse de Recherche Scientifiques, Abidjan, Cote D'Ivoire
| | - Benjamin Koudou
- Centre Suisse de Recherche Scientifiques, Abidjan, Cote D'Ivoire
| | - Sagnon N'Fale
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | | | - Paul Johnson
- Robertson Centre for Biostatistics, University of Glasgow, Glasgow, United Kingdom
| | - Hilary Ranson
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Mark Rowland
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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Re-visiting insecticide resistance status in Anopheles gambiae from Côte d'Ivoire: a nation-wide informative survey. PLoS One 2013; 8:e82387. [PMID: 24358177 PMCID: PMC3864995 DOI: 10.1371/journal.pone.0082387] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 10/28/2013] [Indexed: 11/19/2022] Open
Abstract
Insecticide resistance constitutes a major threat that may undermine current gain in malaria control in most endemic countries. National Malaria Control Programmes (NMCPs) need as much information as possible on the resistance status of malaria vectors and underlying mechanisms in order to implement the most relevant and efficient control strategy. Bioassays, biochemical and molecular analysis were performed on An. gambiae collected in six sentinel sites in Côte d'Ivoire. The sites were selected on the basis of their bioclimatic status and agricultural practices. An. gambiae populations across sites showed high levels of resistance to organochloride, pyrethroid and carbamate insecticides. The kdr and ace-1(R) mutations were detected in almost all sentinel sites with mosquitoes on the coastal and cotton growing areas mostly affected by these mutations. At almost all sites, the levels of detoxifying enzymes (mixed-function oxidases (MFOs), non-specific esterases (NSE) and glutathione-S-transferases (GSTs)) in An. gambiae populations were significantly higher than the levels found in the susceptible strain Kisumu. Pre-exposure of mosquitoes to PBO, an inhibitor of MFOs and NSEs, significantly increased mortality rates to pyrethroids and carbamates in mosquitoes but resistance in most cases was not fully synergised by PBO, inferring a residual role of additional mechanisms, including kdr and ace-1 site insensitivity. The large distribution of resistance in Côte d'Ivoire raises an important question of whether to continue to deploy pyrethroid-based long-lasting insecticidal nets (LLINs) and insecticide residual spraying (IRS) towards which resistance continues to rise with no guarantee that the level of resistance would not compromise their efficacy. Innovative strategies that combine insecticide and synergists in LLINs or spatially LLIN and an effective non-pyrethroid insecticide for IRS could be in the short term the best practice for the NMCP to manage insecticide resistance in malaria vectors in Côte d'Ivoire and other endemic countries facing resistance.
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Pennetier C, Bouraima A, Chandre F, Piameu M, Etang J, Rossignol M, Sidick I, Zogo B, Lacroix MN, Yadav R, Pigeon O, Corbel1 V. Efficacy of Olyset® Plus, a new long-lasting insecticidal net incorporating permethrin and piperonyl-butoxide against multi-resistant malaria vectors [corrected]. PLoS One 2013; 8:e75134. [PMID: 24116029 PMCID: PMC3792972 DOI: 10.1371/journal.pone.0075134] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 08/07/2013] [Indexed: 12/22/2022] Open
Abstract
Due to the rapid extension of pyrethroid resistance in malaria vectors worldwide, manufacturers are developing new vector control tools including insecticide mixtures containing at least two active ingredients with different mode of action as part of insecticide resistance management. Olyset® Plus is a new long-lasting insecticidal net (LLIN) incorporating permethrin and a synergist, piperonyl butoxide (PBO), into its fibres in order to counteract metabolic-based pyrethroid resistance of mosquitoes. In this study, we evaluated the efficacy of Olyset® Plus both in laboratory and field against susceptible and multi-resistant malaria vectors and compared with Olyset Net, which is a permethrin incorporated into polyethylene net. In laboratory, Olyset® Plus performed better than Olyset® Net against susceptible Anopheles gambiae strain with a 2-day regeneration time owing to an improved permethrin bleeding rate with the new incorporation technology. It also performed better than Olyset® Net against multiple resistant populations of An. gambiae in experimental hut trials in West Africa. Moreover, the present study showed evidence for a benefit of incorporating a synergist, PBO, with a pyrethroid insecticide into mosquito netting. These results need to be further validated in a large-scale field trial to assess the durability and acceptability of this new tool for malaria vector control.
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Affiliation(s)
- Cédric Pennetier
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Cotonou, Bénin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Aziz Bouraima
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Cotonou, Bénin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Fabrice Chandre
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France
| | - Michael Piameu
- Laboratory of Medical Entomology, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Centre Supérieur des Sciences de la Santé, Université Catholique d’Afrique Centrale, Yaoundé, Cameroon
| | - Josiane Etang
- Laboratory of Medical Entomology, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, The University of Douala, Douala, Cameroon
| | - Marie Rossignol
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France
| | - Ibrahim Sidick
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Cotonou, Bénin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Barnabas Zogo
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Cotonou, Bénin
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Bénin
| | - Marie-Noëlle Lacroix
- Institut de Recherche pour le Développement (IRD), Maladies Infectieuses et Vecteurs, Ecologie, Genetique, Evolution et Controle (MIVEGEC), UM1-UM2-CNRS 5290 IRD 224, Montpellier, France
| | - Rajpal Yadav
- Vector Ecology and Management, Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Olivier Pigeon
- Walloon Agricultural Research Centre (CRA-W), Agriculture and Natural Environment Department, Plant Protection Products and Biocides Physico-chemistry and Residues Unit, Gembloux, Belgium
| | - Vincent Corbel1
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
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Gnankiné O, Bassolé IH, Chandre F, Glitho I, Akogbeto M, Dabiré RK, Martin T. Insecticide resistance in Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Anopheles gambiae Giles (Diptera: Culicidae) could compromise the sustainability of malaria vector control strategies in West Africa. Acta Trop 2013; 128:7-17. [PMID: 23792227 DOI: 10.1016/j.actatropica.2013.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/29/2013] [Accepted: 06/09/2013] [Indexed: 10/26/2022]
Abstract
Insecticides from the organophosphate (OP) and pyrethroid (PY) chemical families, have respectively, been in use for 50 and 30 years in West Africa, mainly against agricultural pests, but also against vectors of human disease. The selection pressure, with practically the same molecules year after year (mainly on cotton), has caused insecticide resistance in pest populations such as Bemisia tabaci, vector of harmful phytoviruses on vegetables. The evolution toward insecticide resistance in malaria vectors such as Anopheles gambiae sensus lato (s.l.) is probably related to the current use of these insecticides in agriculture. Thus, successful pest and vector control in West Africa requires an investigation of insect susceptibility, in relation to the identification of species and sub species, such as molecular forms or biotypes. Identification of knock down resistance (kdr) and acetylcholinesterase gene (Ace1) mutations modifying insecticide targets in individual insects and measure of enzymes activity typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase) are indispensable in understanding the mechanisms of resistance. Insecticide resistance is a good example in which genotype-phenotype links have been made successfully. Insecticides used in agriculture continue to select new resistant populations of B. tabaci that could be from different biotype vectors of plant viruses. As well, the evolution of insecticide resistance in An. gambiae threatens the management of malaria vectors in West Africa. It raises the question of priority in the use of insecticides in health and/or agriculture, and more generally, the question of sustainability of crop protection and vector control strategies in the region. Here, we review the susceptibility tests, biochemical and molecular assays data for B. tabaci, a major pest in cotton and vegetable crops, and An. gambiae, main vector of malaria. The data reviewed was collected in Benin and Burkina Faso between 2008 and 2010 under the Corus 6015 research program. This review aims to show: (i) the insecticide resistance in B. tabaci as well as in An. gambiae; and (ii) due to this, the impact of selection of resistant populations on malaria vector control strategies. Some measures that could be beneficial for crop protection and vector control strategies in West Africa are proposed.
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Aïzoun N, Aïkpon R, Gnanguenon V, Oussou O, Agossa F, Padonou G, Akogbéto M. Status of organophosphate and carbamate resistance in Anopheles gambiae sensu lato from the south and north Benin, West Africa. Parasit Vectors 2013; 6:274. [PMID: 24330550 PMCID: PMC3856461 DOI: 10.1186/1756-3305-6-274] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 09/17/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With the rapid spread of pyrethroid resistance in the main malaria vectors from Benin and the various resistance mechanisms involved (metabolic resistance and knock-down resistance (kdr), it is important to foresee effective resistance management strategies. Thus, the knowledge of the insensitive acetylcholinesterase (ace-1R) effects on phenotypes of An. gambiae will help us to strengthen basic and operational research on the development of strategies that will use organophosphates or carbamates as alternatives against pyrethroids-resistant malaria vectors in the field. METHODS Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Ouemé , Atacora, and Alibori departments. CDC susceptibility tests were conducted on unfed female mosquitoes aged 2-5 days old. CDC bioassays were performed with stock solutions of fenitrothion (50 μg per bottle) and bendiocarb (12.5 μg per bottle). PCR techniques were used to detect species and Ace-1 mutations. RESULTS Anopheles gambiae Seme and Kandi populations were susceptible to fenitrothion whereas Anopheles gambiae Tanguieta and Malanville populations were resistant. An. gambiae populations from Seme, Kandi and Malanville were fully susceptible to bendiocarb whereas those from Tanguieta have developed a strong resistance to the same insecticide. A slight decrease in mortality rate was observed with 97.91% in populations of mosquitoes from Malanville. PCR revealed that all specimens tested were Anopheles gambiae s.s.. CONCLUSION This study demonstrated the need to monitor organophosphate (OPs) and Carbamates resistance among populations of the An. gambiae s.l. in Benin, to determine its spread and anticipate vector control failure where these insecticides are used. However, further studies are needed to understand the current distribution of the Ace-1R mutation in other localities in the south-north transect Benin.
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Modelling the risk of being bitten by malaria vectors in a vector control area in southern Benin, west Africa. Parasit Vectors 2013; 6:71. [PMID: 23497700 PMCID: PMC3605808 DOI: 10.1186/1756-3305-6-71] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 03/06/2013] [Indexed: 01/18/2023] Open
Abstract
Background The diversity of malaria vector populations, expressing various resistance and/or behavioural patterns could explain the reduced effectiveness of vector control interventions reported in some African countries. A better understanding of the ecology and distribution of malaria vectors is essential to design more effective and sustainable strategies for malaria control and elimination. Here, we analyzed the spatio-temporal risk of the contact between humans and the sympatric An. funestus and both M and S molecular forms of An. gambiae s.s. in an area of Benin with high coverage of vector control measures with an unprecedented level of resolution. Methods Presence-absence data for the three vectors from 1-year human-landing collections in 19 villages were assessed using binomial mixed-effects models according to vector control measures and environmental covariates derived from field and remote sensing data. After 8-fold cross-validations of the models, predictive maps of the risk of the contact between humans and the sympatric An. funestus and both molecular M and S forms of An. gambiae s.s. were computed. Results Model validations showed that the An. funestus, An. gambiae M form, and S form models provided an excellent (Area Under Curve>0.9), a good (AUC>0.8), and an acceptable (AUC>0.7) level of prediction, respectively. The distribution area of the probability of contact between human and An. funestus largely overlaps that of An. gambiae M form but this latter showed important seasonal variation. An. gambiae S form also showed seasonal variation but with different ecological preferences. Landscape data were useful to discriminate between the species’ distributions. Conclusions These results showed that available remote sensing data could help in predicting the human-vector contact for several species of malaria vectors at a village level scale. The predictive maps showed seasonal and spatial variations in the risk of human-vector contact for all three vectors. Such maps could help Malaria Control Programmes to implement more effective vector control strategy by taking into account to the dynamics of malaria vector species.
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Abstract
Understanding genetic causes and effects of speciation in sympatric populations of sexually reproducing eukaryotes is challenging, controversial, and of practical importance for controlling rapidly evolving pests and pathogens. The major African malaria vector mosquito Anopheles gambiae sensu stricto (s.s.) is considered to contain two incipient species with strong reproductive isolation, hybrids between the M and S molecular forms being very rare. Following recent observations of higher proportions of hybrid forms at a few sites in West Africa, we conducted new surveys of 12 sites in four contiguous countries (The Gambia, Senegal, Guinea-Bissau, and Republic of Guinea). Identification and genotyping of 3499 A. gambiae s.s. revealed high frequencies of M/S hybrid forms at each site, ranging from 5 to 42%, and a large spectrum of inbreeding coefficient values from 0.11 to 0.76, spanning most of the range expected between the alternative extremes of panmixia and assortative mating. Year-round sampling over 2 years at one of the sites in The Gambia showed that M/S hybrid forms had similar relative frequencies throughout periods of marked seasonal variation in mosquito breeding and abundance. Genome-wide scans with an Affymetrix high-density single-nucleotide polymorphism (SNP) microarray enabled replicate comparisons of pools of different molecular forms, in three separate populations. These showed strong differentiation between M and S forms only in the pericentromeric region of the X chromosome that contains the molecular form-specific marker locus, with only a few other loci showing minor differences. In the X chromosome, the M/S hybrid forms were more differentiated from M than from S forms, supporting a hypothesis of asymmetric introgression and backcrossing.
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Gouin T, Armitage JM, Cousins IT, Muir DCG, Ng CA, Reid L, Tao S. Influence of global climate change on chemical fate and bioaccumulation: the role of multimedia models. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:20-31. [PMID: 23136071 PMCID: PMC3601418 DOI: 10.1002/etc.2044] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 05/08/2012] [Accepted: 09/06/2012] [Indexed: 05/20/2023]
Abstract
Multimedia environmental fate models are valuable tools for investigating potential changes associated with global climate change, particularly because thermodynamic forcing on partitioning behavior as well as diffusive and nondiffusive exchange processes are implicitly considered. Similarly, food-web bioaccumulation models are capable of integrating the net effect of changes associated with factors such as temperature, growth rates, feeding preferences, and partitioning behavior on bioaccumulation potential. For the climate change scenarios considered in the present study, such tools indicate that alterations to exposure concentrations are typically within a factor of 2 of the baseline output. Based on an appreciation for the uncertainty in model parameters and baseline output, the authors recommend caution when interpreting or speculating on the relative importance of global climate change with respect to how changes caused by it will influence chemical fate and bioavailability.
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Affiliation(s)
- Todd Gouin
- Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom.
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Asidi A, N'Guessan R, Akogbeto M, Curtis C, Rowland M. Loss of household protection from use of insecticide-treated nets against pyrethroid-resistant mosquitoes, benin. Emerg Infect Dis 2012; 18:1101-6. [PMID: 22709930 PMCID: PMC3376816 DOI: 10.3201/eid1807.120218] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Restoring protection requires innovation combining pyrethroids and novel insecticides. Pyrethroid resistance is becoming widespread in Anopheles gambiae mosquitoes, coinciding with expanded use of insecticide-treated nets (ITNs) throughout Africa. To investigate whether nets in use are still protective, we conducted household trials in northern and southern Benin, where An. gambiae mosquitoes are susceptible and resistant, respectively, to pyrethroids. Rooms were fitted with window traps and monitored for mosquito biting and survival rates before and after the nets were treated with pyrethroid. Sleeping under an ITN in the location with resistant mosquitoes was no more protective than sleeping under an untreated net, regardless of its physical condition. By contrast, sleeping under an ITN in the location with susceptible mosquitoes decreased the odds of biting by 66%. ITNs provide little or no protection once the mosquitoes become resistant and the netting acquires holes. Resistance seriously threatens malaria control strategies based on ITN.
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Affiliation(s)
- Alex Asidi
- London School of Hygiene & Tropical Medicine, London, UK
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Abagli AZ, Alavo TBC, Platzer EG. Efficacy of the insect parasitic nematode, Romanomermis iyengari, for malaria vector control in Benin West Africa. Malar J 2012. [PMCID: PMC3472351 DOI: 10.1186/1475-2875-11-s1-p5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Jones CM, Toé HK, Sanou A, Namountougou M, Hughes A, Diabaté A, Dabiré R, Simard F, Ranson H. Additional selection for insecticide resistance in urban malaria vectors: DDT resistance in Anopheles arabiensis from Bobo-Dioulasso, Burkina Faso. PLoS One 2012; 7:e45995. [PMID: 23049917 PMCID: PMC3457957 DOI: 10.1371/journal.pone.0045995] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/23/2012] [Indexed: 11/18/2022] Open
Abstract
In the city of Bobo-Dioulasso in Burkina Faso, Anopheles arabiensis has superseded Anopheles gambiae s.s. as the major malaria vector and the larvae are found in highly polluted habitats normally considered unsuitable for Anopheles mosquitoes. Here we show that An. gambiae s.l. adults emerging from a highly polluted site in the city centre (Dioulassoba) have a high prevalence of DDT resistance (percentage mortality after exposure to diagnostic dose = 65.8% in the dry season and 70.4% in the rainy season, respectively). An investigation into the mechanisms responsible found an unexpectedly high frequency of the 1014S kdr mutation (allele frequency = 0.4), which is found at very low frequencies in An. arabiensis in the surrounding rural areas, and an increase in transcript levels of several detoxification genes, notably from the glutathione transferase and cytochrome P450 gene families. A number of ABC transporter genes were also expressed at elevated levels in the DDT resistant An. arabiensis. Unplanned urbanisation provides numerous breeding grounds for mosquitoes. The finding that Anopheles mosquitoes adapted to these urban breeding sites have a high prevalence of insecticide resistance has important implications for our understanding of the selective forces responsible for the rapid spread of insecticide resistant populations of malaria vectors in Africa.
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Affiliation(s)
- Christopher M. Jones
- Vector Group, Liverpool School of Tropical Medicine, Liverpool, Merseyside, United Kingdom
- * E-mail:
| | - Hyacinthe K. Toé
- Vector Group, Liverpool School of Tropical Medicine, Liverpool, Merseyside, United Kingdom
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Centre National de Recherche et de la Formation sur Paludisme, Ouagadougou, Burkina Faso
| | - Antoine Sanou
- Centre National de Recherche et de la Formation sur Paludisme, Ouagadougou, Burkina Faso
| | - Moussa Namountougou
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Angela Hughes
- Vector Group, Liverpool School of Tropical Medicine, Liverpool, Merseyside, United Kingdom
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Roch Dabiré
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Frederic Simard
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
- Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de Recherche pour le Développement, Montpellier, France
| | - Hilary Ranson
- Vector Group, Liverpool School of Tropical Medicine, Liverpool, Merseyside, United Kingdom
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Moiroux N, Gomez MB, Pennetier C, Elanga E, Djènontin A, Chandre F, Djègbé I, Guis H, Corbel V. Changes in Anopheles funestus biting behavior following universal coverage of long-lasting insecticidal nets in Benin. J Infect Dis 2012; 206:1622-9. [PMID: 22966127 DOI: 10.1093/infdis/jis565] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Behavioral modification of malaria vectors in response to vector control methods is of great concern. We investigated whether full coverage of long-lasting insecticide-treated mosquito nets (LLINs) may induce a switch in biting behavior in Anopheles funestus, a major malaria vector in Africa. METHODS Human-landing collections were conducted indoor and outdoor in 2 villages (Lokohouè and Tokoli) in Benin before and 1 year and 3 years after implementation of universal LLIN coverage. Proportion of outdoor biting (POB) and median catching times (MCT) were compared. The resistance of A. funestus to deltamethrin was monitored using bioassays. RESULTS MCT of A. funestus switched from 2 AM in Lokohoué and 3 AM in Tokoli to 5 AM after 3 years (Mann-Whitney U test, P < .0001). In Tokoli, POB increased from 45% to 68.1% (odds ratio = 2.55; 95 confidence interval = 1.72-3.78; P < .0001) 1 year after the universal coverage, whereas POB was unchanged in Lokohoué. In Lokohoué, however, the proportion of A. funestus that bites after 6 am was 26%. Bioassays showed no resistance to deltamethrin. CONCLUSIONS This study provides evidence for a switch in malaria vectors' biting behavior after the implementation of LLIN at universal coverage. These findings might have direct consequences for malaria control in Africa and highlighted the need for alternative strategies for better targeting malaria vectors.
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Affiliation(s)
- Nicolas Moiroux
- MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), Institut de Recherche pour le Développement, Montpellier, France
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Padonou GG, Sezonlin M, Ossé R, Aizoun N, Oké-Agbo F, Oussou O, Gbédjissi G, Akogbéto M. Impact of three years of large scale Indoor Residual Spraying (IRS) and Insecticide Treated Nets (ITNs) interventions on insecticide resistance in Anopheles gambiae s.l. in Benin. Parasit Vectors 2012; 5:72. [PMID: 22490146 PMCID: PMC3379941 DOI: 10.1186/1756-3305-5-72] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Accepted: 04/10/2012] [Indexed: 11/17/2022] Open
Abstract
Background In Benin, Indoor Residual Spraying (IRS) and long-lasting insecticidal nets (LLINs) are the cornerstones of malaria prevention. In the context of high resistance of Anopheles gambiae to pyrethroids, The National Malaria Control Program (NMCP) has undertaken a full coverage of IRS in a no-flood zone in the Oueme region, coupled with the distribution of LLINs in a flood zone. We assessed the impact of this campaign on phenotypic resistance, kdr (knock-down resistance) and ace-1R (insensitive acetylcholinesterase) mutations. Methods Insecticides used for malaria vector control interventions were bendiocarb WP (0.4 g/m2) and deltamethrin (55 mg/m2), respectively for IRS and LLINs. Susceptibility status of An. gambiae was assessed using World Health Organization bioassay tests to DDT, permethrin, deltamethrin and bendiocarb in the Oueme region before intervention (2007) and after interventions in 2008 and 2010. An. gambiae specimens were screened for identification of species, molecular M and S forms and for the detection of the West African kdr (L1014F) as well as ace-1R mutations using PCR techniques. Results The univariate logistic regression performed showed that kdr frequency has increased significantly during the three years in the intervention area and in the control area. Several factors (LLINs, IRS, mosquito coils, aerosols, use of pesticides for crop protection) could explain the selection of individual resistant An. gambiae. The Kdr resistance gene could not be the only mechanism of resistance observed in the Oueme region. The high susceptibility to bendiocarb is in agreement with a previous study conducted in Benin. However, the occurrence of ace-1R heterozygous individuals even on sites far from IRS areas, suggests other factors may contribute to the selection of resistance other than those exerted by the vector control program. Conclusion The results of this study have confirmed that An.gambiae have maintained and developed the resistance to pyrethroids, but are still susceptible to bendiocarb. Our data clearly shows that selection of resistant individuals was caused by other insecticides than those used by the IRS and LLINs.
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Affiliation(s)
- Gil Germain Padonou
- Faculté des Sciences et Techniques de l'Université d'Abomey Calavi, Calavi, Bénin.
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Exploring mechanisms of multiple insecticide resistance in a population of the malaria vector Anopheles funestus in Benin. PLoS One 2011; 6:e27760. [PMID: 22110757 PMCID: PMC3218031 DOI: 10.1371/journal.pone.0027760] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 10/24/2011] [Indexed: 11/24/2022] Open
Abstract
Background The insecticide resistance status of the malaria vector Anopheles funestus and the underlying resistance mechanisms remain uncharacterised in many parts of Africa, notably in Benin, West Africa. To fill this gap in our knowledge, we assessed the susceptibility status of a population of this species in Pahou, Southern Benin and investigated the potential resistance mechanisms. Methodology/Principal Findings WHO bioassays revealed a multiple resistance profile for An. funestus in Pahou. This population is highly resistant to DDT with no mortality in females after 1h exposure to 4%DDT. Resistance was observed against the Type I pyrethroid permethrin and the carbamate bendiocarb. A moderate resistance was detected against deltamethrin (type II pyrethroids). A total susceptibility was observed against malathion, an organophosphate. Pre-exposure to PBO did not change the mortality rates for DDT indicating that cytochrome P450s play no role in DDT resistance in Pahou. No L1014F kdr mutation was detected but a correlation between haplotypes of two fragments of the Voltage-Gated Sodium Channel gene and resistance was observed suggesting that mutations in other exons may confer the knockdown resistance in this species. Biochemical assays revealed elevated levels of GSTs and cytochrome mono-oxygenases in Pahou. No G119S mutation and no altered acetylcholinesterase gene were detected in the Pahou population. qPCR analysis of five detoxification genes revealed that the GSTe2 is associated to the DDT resistance in this population with a significantly higher expression in DDT resistant samples. A significant over-expression of CYP6P9a and CYP6P9b previously associated with pyrethroid resistance was also seen but at a lower fold change than in southern Africa. Conclusion The multiple insecticide resistance profile of this An. funestus population in Benin shows that more attention should be paid to this important malaria vector for the implementation and management of current and future malaria vector control programs in this country.
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Djègbè I, Boussari O, Sidick A, Martin T, Ranson H, Chandre F, Akogbéto M, Corbel V. Dynamics of insecticide resistance in malaria vectors in Benin: first evidence of the presence of L1014S kdr mutation in Anopheles gambiae from West Africa. Malar J 2011; 10:261. [PMID: 21910856 PMCID: PMC3179749 DOI: 10.1186/1475-2875-10-261] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 09/12/2011] [Indexed: 11/10/2022] Open
Abstract
Background Insecticide resistance monitoring is essential to help national programmers to implement more effective and sustainable malaria control strategies in endemic countries. This study reported the spatial and seasonal variations of insecticide resistance in malaria vectors in Benin, West Africa. Methods Anopheles gambiae s.l populations were collected from October 2008 to June 2010 in four sites selected on the basis of different use of insecticides and environment. WHO susceptibility tests were carried out to detect resistance to DDT, fenitrothion, bendiocarb, permethrin and deltamethrin. The synergist piperonyl butoxide was used to assess the role of non-target site mechanisms in pyrethroid resistance. Anopheles gambiae mosquitoes were identified to species and to molecular M and S forms using PCR techniques. Molecular and biochemical assays were carried out to determine kdr and Ace.1R allelic frequencies and activity of the detoxification enzymes. Results Throughout the surveys very high levels of mortality to bendiocarb and fenitrothion were observed in An. gambiae s.l. populations. However, high frequencies of resistance to DDT and pyrethroids were seen in both M and S form of An. gambiae s.s. and Anopheles arabiensis. PBO increased the toxicity of permethrin and restored almost full susceptibility to deltamethrin. Anopheles gambiae s.l. mosquitoes from Cotonou and Malanville showed higher oxidase activity compared to the Kisumu susceptible strain in 2009, whereas the esterase activity was higher in the mosquitoes from Bohicon in both 2008 and 2009. A high frequency of 1014F kdr allele was initially showed in An. gambiae from Cotonou and Tori-Bossito whereas it increased in mosquitoes from Bohicon and Malanville during the second year. For the first time the L1014S kdr mutation was found in An. arabiensis in Benin. The ace.1R mutation was almost absent in An. gambiae s.l. Conclusion Pyrethroid and DDT resistance is widespread in malaria vector in Benin and both metabolic and target site resistance are implicated. Resistance was not correlated with a change of malaria species and/or molecular forms. The 1014S kdr allele was first identified in wild population of An. arabiensis hence confirming the expansion of pyrethroid resistance alleles in Africa.
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Affiliation(s)
- Innocent Djègbè
- Centre de Recherche Entomologique de Cotonou, 06 BP 2604, Cotonou, Bénin.
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