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Agbevo A, Ahogni I, Menze B, Tungu P, Kemibala EE, Govoetchan R, Wondji C, Padonou GG, Ngufor C. Community evaluation of the physical and insecticidal durability of DuraNet® Plus, an alpha-cypermethrin and piperonyl butoxide incorporated mosquito net: protocol for a multi-country study in West, Central and East Africa. Arch Public Health 2023; 81:202. [PMID: 37986195 PMCID: PMC10662531 DOI: 10.1186/s13690-023-01217-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 11/09/2023] [Indexed: 11/22/2023] Open
Abstract
BACKGROUND Pyrethroid-PBO nets have demonstrated improved impact against clinical malaria transmitted by pyrethroid resistant mosquito vectors and are being scaled up across Africa. However very little is known about their physical and insecticidal durability under operational conditions. This study will investigate the attrition, fabric integrity, insecticide content and bioefficacy of DuraNet® Plus, a new WHO prequalified alphacypermethrin and PBO incorporated net developed by Shobikaa Impex Private Limited over 3 years of field use in communities in Benin, Cameroon and Tanzania. METHODS The study will be conducted in parallel in selected villages in Zakpota District in Benin, Mbalmayo, District in Cameroon and Muheza District in Tanzania. In each country, ~ 1800 households will be recruited and randomised to receive DuraNet® Plus or DuraNet® (a WHO prequalified alphacypermethrin-only ITN). Follow up surveys will be performed at 1 month post distribution to investigate adverse events and subsequently every 6-12 months to assess ITN attrition and fabric integrity following standard WHO procedures. A second cohort of nets will be withdrawn every 6-12 months and assessed for alpha-cypermethrin and PBO content and for entomological activity in laboratory bioassays (cone bioassays and tunnel tests). Alpha-cypermethrin bioefficacy will be monitored using the susceptible Anopheles gambiae Kisumu strain in cone bioassays while PBO bioefficacy will be monitored using pyrethroid resistant strains with overexpressed P450 enzymes in tunnel tests to determine the proportion of efficacious nets (≥ 95% knockdown, ≥ 80% mortality or ≥ 90% blood feeding inhibition in tunnels) at each time point. Nets withdrawn at 12, 24 and 36 months from each country will also be tested in experimental hut trials against wild free-flying pyrethroid resistant Anopheles gambiae sl in Côvè Benin to investigate the superiority of DuraNet® Plus over DuraNet® at each time point under semi field conditions. CONCLUSION This large-scale multi country trial will provide useful information on the durability of a pyrethroid-PBO net (DuraNet® Plus) in 3 different regions in sub-Saharan Africa. The methods proposed for bioefficacy testing could also contribute towards the development of new standardised guidelines for monitoring the insecticidal efficacy of pyrethroid-PBO nets under operational conditions.
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Affiliation(s)
- Abel Agbevo
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC-BENIN), Cotonou, Benin
- London School of Hygiene and Tropical Medicine (LSHTM), London, UK
| | - Idelphonse Ahogni
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC-BENIN), Cotonou, Benin
| | - Benjamin Menze
- Centre for Research in Infectious Diseases (CRID) ), Yaoundé, Cameroon
| | - Patrick Tungu
- Vector Control Training Centre (VCTC), Muheza, Tanzania
- National Institute for Medical Research (NIMR), Amani Research Centre, Tanga, Tanzania
| | | | - Renaud Govoetchan
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin
- Panafrican Malaria Vector Research Consortium (PAMVERC-BENIN), Cotonou, Benin
- London School of Hygiene and Tropical Medicine (LSHTM), London, UK
| | - Charles Wondji
- Centre for Research in Infectious Diseases (CRID) ), Yaoundé, Cameroon
- Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Corine Ngufor
- Centre de Recherches Entomologiques de Cotonou (CREC), Cotonou, Benin.
- Panafrican Malaria Vector Research Consortium (PAMVERC-BENIN), Cotonou, Benin.
- London School of Hygiene and Tropical Medicine (LSHTM), London, UK.
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Kpanou CD, Sagbohan HW, Sovi A, Osse R, Padonou GG, Salako A, Tokponnon F, Fassinou AJ, Yovogan B, Nwangwu UC, Adoha CJ, Odjo EM, Ahogni I, Sidick A, Saïd Baba-Moussa L, Akogbéto M. Assessing Insecticide Susceptibility and Resistance Intensity of Anopheles gambiae s.l. Populations From Some Districts of Benin Republic, West Africa. J Med Entomol 2022; 59:949-956. [PMID: 35357491 DOI: 10.1093/jme/tjac037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Indexed: 06/14/2023]
Abstract
Pyrethroid resistance is widespread in sub-Saharan Africa. The objective of this study was to assess the insecticide resistance intensity in Anopheles gambiae s.l. (Diptera: Culicidae) in four districts of Benin in order to better understand how pyrethroid-only nets are likely to be effective. Thus, adult females of An. gambiae s.l., reared from field-collected larvae were used for assessing resistance intensity to permethrin and deltamethrin. They were tested at 1×, 5×, and 10× the diagnostic dose, using both WHO susceptibility tube testing and CDC bottle bioassays. Identification of molecular species, as well as of L1014F Kdr and Ace-1R mutations was performed using the PCR. The level of expression of biochemical enzymes was also evaluated. Overall, moderate to high resistance intensity to permethrin and deltamethrin was observed, irrespective of the testing method. While the L1014F Kdr frequency was high (>75%), Ace-1R was low (≤6%) in An. gambiaes.s. and Anopheles coluzzii, the two predominant species [52% (95% CI: 44.8-59.1) and 45% (95% CI: 38.0-52.2), respectively]. Anopheles arabiensis was found at very low frequency (3%, 95%CI: 1.1-6.4). For Biochemical analyses, α and β-esterases were over-expressed in all four districts, while mixed-function oxidases (MFOs) were over-expressed in only one. Overall, the two testing methods led to comparable conclusions, though there were a few inconsistencies between them. The moderate-high resistance intensity observed in the study area suggests that dual active-ingredient (AI) long-lasting insecticidal nets (LLINs) may provide better control of insecticide-resistant mosquitoes.
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Affiliation(s)
- Casimir Dossou Kpanou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Hermann W Sagbohan
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Arthur Sovi
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Department of Sciences and Techniques for Animal and Fisheries Production, Faculty of Agronomy, University of Parakou, BP 123 Parakou, Benin
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HT, UK
| | - Razaki Osse
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département des Sciences Animales et Halieutiques, École de gestion et d'exploitation des systèmes d'élevage, Université Nationale d'Agriculture de Porto-Novo, BP 43 Kétou, Bénin
| | - Gil G Padonou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Albert Salako
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Filémon Tokponnon
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Arsène Jacques Fassinou
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Boulais Yovogan
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Udoka C Nwangwu
- Department of Disease Surveillance, National Arbovirus and Vectors Research Centre (NAVRC), 4 Park Ave, GRA 400102, Enugu, Nigeria
| | - Constantin J Adoha
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Esdras Mahoutin Odjo
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Idelphonse Ahogni
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Aboubakar Sidick
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
| | - Lamine Saïd Baba-Moussa
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
| | - Martin Akogbéto
- Département de Biologie des Vecteurs, Centre de Recherche entomologique de Cotonou (CREC), 06 BP 2604 Cotonou, Benin
- Département de Zoologie, Faculté des Sciences et Techniques, University of Abomey-Calavi, 01 BP 526 Abomey-Calavi, Benin
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Sagbohan HW, Kpanou CD, Sovi A, Osse R, Sidick A, Adoha C, Yovogan B, Salako AS, Ahogni I, Fassinou A, Sominanhouin A, Chitou S, Padonou GG, Agbangla C, Akogbeto M. Pyrethroid Resistance Intensity in Anopheles gambiae s.l. from Different Agricultural Production Zones in Benin, West Africa. Vector Borne Zoonotic Dis 2022; 22:39-47. [PMID: 35030048 DOI: 10.1089/vbz.2021.0066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023] Open
Abstract
Agricultural production activities usually occur in Benin with the use of a huge amount of insecticides including pyrethroids for pest control. It is therefore important to regularly monitor pyrethroid resistance intensity in Anopheles gambiae s.l., the main malaria vector. This study was conducted in cereal, cotton, rice growing, and urban market gardening areas throughout the country in 2018 and 2019. Females An. gambiae s.l. field-collected as larvae were exposed to deltamethrin 1 × (0.05%), 2 × (0.1%), 5 × (0.25%), and 10 × (0.5%) and permethrin 1 × (0.75%), 2 × (1.5%), 5 × (3.75%), and 10 × (7.5%). Synergist assays were also performed using World Health Organization articles combining piperonyl butoxide (PBO) (4%) + deltamethrin 1 × and, PBO (4%) + Permethrin 1 × . Molecular species and L1014F kdr mutation were identified using PCR. Expression of metabolic enzymes was also assessed through biochemical tests. After exposure to permethrin and deltamethrin 10 × , An. gambiae s.l. displayed mortality rates <98%. Synergist assays induced significantly higher mortality rates than pyrethroids alone (p < 0.05). An. gambiae s.l. complex was composed of An. gambiae s.s., Anopheles coluzzii, and Anopheles arabiensis, with mean frequency of the L1014F kdr mutation >75%. Overexpression of nonspecific α and β esterases was observed in the cereal, cotton, and urban market gardening areas, while an overexpression of mixed function oxidases was observed in the cotton and rice growing areas. Overall, An. gambiae s.l. showed high resistance intensity to both deltamethrin and permethrin. The synergist and biochemical tests performed suggest that PBO long-lasting insecticidal nets may provide a greater control of pyrethroid-resistant mosquitoes.
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Affiliation(s)
- Hermann Watson Sagbohan
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Casimir D Kpanou
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Arthur Sovi
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Animal Production, Faculty of Agronomy, University of Parakou, Parakou, Benin
- Disease Control Department, Faculty of Infectious and Tropical Diseases, The London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Razaki Osse
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Animal and Fishery Sciences, National University of Agriculture of Porto-Novo, Porto-Novo, Benin
| | - Aboubakar Sidick
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Constantin Adoha
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Boulais Yovogan
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Albert S Salako
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Idelphonse Ahogni
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Arsène Fassinou
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - André Sominanhouin
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Saïd Chitou
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
| | - Germain G Padonou
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Clément Agbangla
- Department of Zoology, Faculty of Sciences and Techniques, University of Abomey-Calavi, Abomey-Calavi, Benin
- Department of Genetics, Genetics and Biotechnology Laboratory, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Martin Akogbeto
- Department of Vector Biology, Center for Research in Entomology of Cotonou, Cotonou, Benin
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Akogbéto MC, Dagnon F, Aïkpon R, Ossé R, Salako AS, Ahogni I, Akinro B, Sominahouin A, Sidick A, Tokponnon F, Padonou GG. Lessons learned, challenges and outlooks for decision-making after a decade of experience monitoring the impact of indoor residual spraying in Benin, West Africa. Malar J 2020; 19:45. [PMID: 31992318 PMCID: PMC6986099 DOI: 10.1186/s12936-020-3131-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Since 2008, Indoor Residual Spraying (IRS) has been performed in Benin in 19 districts, including 4 in southern Benin, 9 in Atacora, and 8 in Atacora, Alibori and Donga in northern Benin. However, Benin still struggles with questions about IRS cost-benefit and epidemiological impact. Lessons learned and challenges from 10 years of IRS in Benin to be shared with the stakeholders involved in vector control implementation for decision-making. METHODS Entomological parameters have been assessed entomological parameters in IRS communes since 2008. In all IRS intervention communes, decreases in human biting rate (HBR) of Anopheles gambiae, blood feeding inhibition and entomological inoculation rate (EIR) as compared to control district have been measured. RESULTS EIR was reduced by 80-90%, which is encouraging, but should be observed with caution because: (i) the reduction may be insufficient to decrease epidemiological indicators given that the residual EIR in IRS districts is still higher than it is in some regions of stable malaria; (ii) the reduction in EIR is based on comparisons with control communes, but it is difficult to select control areas with the same environmental characteristics as intervention areas; (iii) despite the reduction, half of all mosquitoes that entered IRS-treated houses succeeded in taking human blood meals. Further, there are behaviours among Benin's population that limit IRS efficacy, including recent data showing that > 90% of people are not protected by IRS between 7 and 10 p.m. This is due to the fact that they remain outdoors and that most people are not protected from mosquito bites after 10 p.m. because they either sleep outdoors without IRS protection or indoors without an ITN. Moreover, people have large amounts of clothing hanging on walls where mosquitoes can rest instead of IRS-treated walls. Finally, other components are important to consider in implementing IRS among which: (i) Vector resistance management strategies are sometimes poorly understood; this is actually different from the need to replace one insecticide with another after the emergence of resistance; (ii) African countries should prepare to finance IRS themselves. CONCLUSION To curtail residual malaria transmission, additional interventions able to target vectors escaping IRS should be prioritized.
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Affiliation(s)
- Martin C Akogbéto
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques, de l' Université d'Abomey-Calavi, Cotonou, Benin
| | - Fortuné Dagnon
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
| | - Rock Aïkpon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Technologies, Ingénierie et Mathématiques, Université Nationale des Sciences, Abomey, Bénin
| | - Razaki Ossé
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Université Nationale d'Agriculture, de Porto-Novo, Bénin
| | - Albert S Salako
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin. .,Faculté des Sciences et Techniques, de l' Université d'Abomey-Calavi, Cotonou, Benin.
| | - Idelphonse Ahogni
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques, de l' Université d'Abomey-Calavi, Cotonou, Benin
| | - Bruno Akinro
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | - André Sominahouin
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences Humaines et Sociales, de l' Université d'Abomey-Calavi, Cotonou, Benin
| | - Aboubakar Sidick
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin
| | | | - Germain G Padonou
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques, de l' Université d'Abomey-Calavi, Cotonou, Benin
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Salako AS, Dagnon F, Sovi A, Padonou GG, Aïkpon R, Ahogni I, Syme T, Govoétchan R, Sagbohan H, Sominahouin AA, Akinro B, Iyikirenga L, Agossa F, Akogbeto MC. Efficacy of Actellic 300 CS-based indoor residual spraying on key entomological indicators of malaria transmission in Alibori and Donga, two regions of northern Benin. Parasit Vectors 2019; 12:612. [PMID: 31888730 PMCID: PMC6937814 DOI: 10.1186/s13071-019-3865-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 12/19/2019] [Indexed: 11/25/2022] Open
Abstract
Background The current study shows the results of three years of IRS entomological monitoring (2016, before intervention; 2017 and 2018, after intervention) performed in Alibori and Donga, northern Benin. Methods Mosquito collections were performed on a monthly basis using human landing catches and pyrethrum spray catches in six districts including four treated with Actellic 300 CS (Kandi, Gogounou, Djougou and Copargo) and two untreated (Bembèrèkè and Kouandé) which served as control sites. Key transmission indicators of Anopheles gambiae (s.l.) as well as the residual activity of Actellic 300 CS assessed through WHO cone tests, were determined. Results The residual efficacy duration of Actellic 300 CS after the two IRS campaigns (2017 and 2018) was 4–5 months (May–September). The parity rate and the sporozoite index of An. gambiae (s.l.) were 36.62% and 0.71%, respectively, after the first spray round in treated areas compared to 57.24% and 3.7%, respectively, in the control areas (P < 0.0001). The same trend was observed after the second spray round. After the first spray round, each person received 1.6 infective bites/month (ib/m) in the treated areas against 12.11 ib/m in the control areas, resulting in a reduction rate of 86.78%. Similarly, the entomological inoculation rate was 1.5 ib/m after the second spray round in the treated areas vs 9.75 ib/m in the control areas, corresponding to a reduction of 84.61%. A decrease in the parity rate (46.26%), sporozoite index (85.75%) and EIR (87.27%) was observed for An. gambiae (s.l.) after the first round of IRS (June–October 2017) compared to the pre-intervention period (June–October 2016). The density of An. gambiae (s.l.) ranged between 0.38–0.48 per house in treated areas vs 1.53–1.76 An. gambiae (s.l.) per house respectively after the first and second IRS rounds. Conclusions This study showed the positive impact of IRS in reducing key entomological parameters of malaria transmission in Alibori and Donga. However, the considerable blood-feeding rate of An. gambiae (s.l.) in spray areas, stress the need for the population to sleep under long-lasting insecticidal nets (LLINs) in addition, to prevent from mosquito bites which did not succeed in resting on sprayed walls.
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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, Cotonou, Benin.
| | - Fortune Dagnon
- USA President's Malaria Initiative, USA Agency for International Development, Cotonou, Benin
| | - Arthur Sovi
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Faculty of Agronomy, University of Parakou, BP 123, Parakou, Benin.,Disease Control Department, Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Gil Germain Padonou
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Rock Aïkpon
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Université Nationale des Sciences, Technologies, Ingénierie et Mathématiques, Abomey, Bénin
| | - Idelphonse Ahogni
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - Thomas Syme
- Disease Control Department, Faculty of Infectious & Tropical Diseases, The London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Renaud Govoétchan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Faculty of Agronomy, University of Parakou, BP 123, Parakou, Benin
| | - Herman Sagbohan
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Cotonou, Benin
| | - 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
| | - Bruno Akinro
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin
| | | | - Fiacre Agossa
- Centre de Recherche Entomologique de Cotonou (CREC), Cotonou, Benin.,PMI VectorLink Project, Abt Associates, Kinshasa, Democratic Republic of Congo
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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: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Salako AS, Ahogni I, Kpanou C, Sovi A, Azondekon R, Sominahouin AA, Tokponnon F, Gnanguenon V, Dagnon F, Iyikirenga L, Akogbeto MC. Baseline entomologic data on malaria transmission in prelude to an indoor residual spraying intervention in the regions of Alibori and Donga, Northern Benin, West Africa. Malar J 2018; 17:392. [PMID: 30373576 PMCID: PMC6206707 DOI: 10.1186/s12936-018-2507-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 10/06/2018] [Indexed: 11/16/2022] Open
Abstract
Background Despite the success of indoor residual insecticide spraying (IRS) in Africa, particularly in Benin, some gaps of information need to be filled to optimize the effectiveness of this intervention in the perspective of the country’s effort to eliminate malaria. In anticipation to the 2018 IRS campaign in two targeted regions of northern Benin, this study aimed, to collect baseline information on vector composition, spatio-temporal variation and peak malaria transmission in the Alibori and Donga, two targeted regions of northern Benin. Information collected will help to better plan the implementation and later on the impact assessment of this IRS campaign. Methods The study was carried out in four districts of the two IRS targeted regions of northern Benin. Human landing catches and pyrethrum spray catches protocols were used to assess the biting rate (HBR) and, biting/resting behaviour of malaria vector populations. After morphological identification of collected Anopheles, the heads and thoraxes of Anopheles gambiae sensu lato (s.l.) were analysed by the ELISA CSP tests to estimate the sporozoite index (SI). The entomological inoculation rate was calculated as the product of mosquito biting rate (HBR) and the SI. Results The biting rates of An. gambiae s.l., the major vector in this study sites, varied significantly from region to region. It was higher: in rural than in urban areas, in rainy season than in dry season, indoors than outdoors. Overall, SI was comparable between sites. The highest EIRs were observed in the Donga region (16.84 infectious bites/man/month in Djougou district and 17.64 infectious bites/man/month in Copargo district) and the lowest in the Alibori region (10.74 infectious bites/man/month at Kandi district and 11.04 infectious bites/man/month at Gogounou district). Conclusion This study showed the heterogeneous and various nature of malaria epidemiology in Northern Benin. Indeed, the epidemiological profile of malaria transmission in the Alibori and Donga regions is made of a single season of transmission interrupted by a dry season. This period of transmission is relatively longer in Donga region than in Alibori. This information can be used to guide the extension of IRS in the Alibori and in the Donga, by primarily targeting areas with short periods of transmission, and easy to cover.
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Affiliation(s)
- Albert S 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
| | - Casimir Kpanou
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,Faculté des Sciences et Techniques de l'Université d'Abomey-Calavi, Abomey-Calavi, Benin
| | - Arthur Sovi
- PMI VectorLink Project, Abt Associates, Bamako, Mali
| | - Roseric Azondekon
- Centre de Recherche entomologique de Cotonou (CREC), Cotonou, Benin.,University of Wisconsin Milwaukee, Milwaukee, WI, USA
| | - André A 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
| | | | | | - Fortuné Dagnon
- US President's Malaria Initiative, US Agency for International Development, Cotonou, Benin
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