Rosine Z Wolie1,2,3, Alphonsine A Koffi4,5, Leslie Ayuk-Taylor6, Ludovic P Ahoua Alou4,5, Eleanore D Sternberg7,8, Oulo N'Nan-Alla9, Yao N'Guessan4,5, Amal Dahounto4, Welbeck A Oumbouke4,10, Innocent Z Tia4,5,11, Simon-Pierre A N'Guetta9, Jackie Cook12, Matthew B Thomas7,13, Raphael N'Guessan4,5,14. 1. Unité de Recherche Et de Pédagogie de Génétique, Université Félix Houphouët-Boigny, UFR Biosciences, Abidjan, Côte d'Ivoire. wolierosine@yahoo.fr. 2. Vector Control Product Evaluation Centre-Institut Pierre Richet (VCPEC-IPR), Institut Pierre Richet (IPR), Bouaké, Côte d'Ivoire. wolierosine@yahoo.fr. 3. Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire. wolierosine@yahoo.fr. 4. Vector Control Product Evaluation Centre-Institut Pierre Richet (VCPEC-IPR), Institut Pierre Richet (IPR), Bouaké, Côte d'Ivoire. 5. Institut Pierre Richet (IPR), Institut National de Santé Publique (INSP), Bouaké, Côte d'Ivoire. 6. DC Department of Health, 899 North Capitol St NE, Washington, USA. 7. Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, USA. 8. Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK. 9. Unité de Recherche Et de Pédagogie de Génétique, Université Félix Houphouët-Boigny, UFR Biosciences, Abidjan, Côte d'Ivoire. 10. Innovative Vector Control Consortium, IVCC, Liverpool, UK. 11. Université Alassane Ouattara, Bouaké, Côte d'Ivoire. 12. Department of Infectious Disease Epidemiology, International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK. 13. York Environmental Sustainability Institute, University of York, York, UK. 14. Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
Abstract
BACKGROUND: A study was conducted prior to implementing a cluster-randomized controlled trial (CRT) of a lethal house lure strategy in central Côte d'Ivoire to provide baseline information on malaria indicators in 40 villages across five health districts. METHODS: Human landing catches (HLC) were performed between November and December 2016, capturing mosquitoes indoors and outdoors between 18.00 and 08.00 h. Mosquitoes were processed for entomological indicators of malaria transmission (human biting, parity, sporozoite, and entomological inoculation rates (EIR)). Species composition and allelic frequencies of kdr-w and ace-1R mutations were also investigated within the Anopheles gambiae complex. RESULTS: Overall, 15,632 mosquitoes were captured. Anopheles gambiae sensu lato (s.l.) and Anopheles funestus were the two malaria vectors found during the survey period, with predominance for An. gambiae (66.2%) compared to An. funestus (10.3%). The mean biting rate for An. gambiae was almost five times higher than that for An. funestus (19.8 bites per person per night for An. gambiae vs 4.3 bites per person per night for An. funestus) and this was evident indoors and outdoors. Anopheles funestus was more competent to transmit malaria parasites in the study area, despite relatively lower number tested for sporozoite index (4.14% (63/1521) for An. gambiae vs 8.01% (59/736) for An. funestus; χ2 = 12.216; P < 0.0001). There were no significant differences between the proportions infected outdoors and indoors for An. gambiae (4.03 vs 4.13%; χ2 = 0.011; P = 0.9197) and for An. funestus (7.89 vs 8.16%; χ2 = 2.58e-29; P = 1). The majority of both infected vectors with malaria parasites harboured Plasmodium falciparum (93.65% for An. gambiae and 98. 31% for An. funestus). Overall, the EIR range for both species in the different districts appeared to be high (0.35-2.20 infected bites per human per night) with the highest value observed in the district of North-Eastern-Bouaké. There were no significant differences between transmission occurring outdoor and indoor for both species. Of the An. gambiae s.l. analysed, only An. gambiae sensu stricto (14.1%) and Anopheles coluzzii (85.9%) were found. The allelic frequencies of kdr and ace-1R were higher in An. gambiae (0.97 for kdr and 0.19 for ace-1R) than in An. coluzzii (0.86 for kdr and 0.10 for ace-1R) (P < 0.001). CONCLUSION: Despite universal coverage with long-lasting insecticidal nets (LLINs) in the area, there was an abundance of the malaria vectors (An. gambiae and An. funestus) in the study area in central Côte d'Ivoire. Consistent with high insecticide resistance intensity previously detected in these districts, the current study detected high kdr frequency (> 85%), coupled with high malaria transmission pattern, which could guide the use of Eave tubes in the study areas.
BACKGROUND: A study was conducted prior to implementing a cluster-randomized controlled trial (CRT) of a lethal house lure strategy in central Côte d'Ivoire to provide baseline information on malaria indicators in 40 villages across five health districts. METHODS: Human landing catches (HLC) were performed between November and December 2016, capturing mosquitoes indoors and outdoors between 18.00 and 08.00 h. Mosquitoes were processed for entomological indicators of malaria transmission (human biting, parity, sporozoite, and entomological inoculation rates (EIR)). Species composition and allelic frequencies of kdr-w and ace-1R mutations were also investigated within the Anopheles gambiae complex. RESULTS: Overall, 15,632 mosquitoes were captured. Anopheles gambiae sensu lato (s.l.) and Anopheles funestus were the two malaria vectors found during the survey period, with predominance for An. gambiae (66.2%) compared to An. funestus (10.3%). The mean biting rate for An. gambiae was almost five times higher than that for An. funestus (19.8 bites per person per night for An. gambiae vs 4.3 bites per person per night for An. funestus) and this was evident indoors and outdoors. Anopheles funestus was more competent to transmit malaria parasites in the study area, despite relatively lower number tested for sporozoite index (4.14% (63/1521) for An. gambiae vs 8.01% (59/736) for An. funestus; χ2 = 12.216; P < 0.0001). There were no significant differences between the proportions infected outdoors and indoors for An. gambiae (4.03 vs 4.13%; χ2 = 0.011; P = 0.9197) and for An. funestus (7.89 vs 8.16%; χ2 = 2.58e-29; P = 1). The majority of both infected vectors with malaria parasites harboured Plasmodium falciparum (93.65% for An. gambiae and 98. 31% for An. funestus). Overall, the EIR range for both species in the different districts appeared to be high (0.35-2.20 infected bites per human per night) with the highest value observed in the district of North-Eastern-Bouaké. There were no significant differences between transmission occurring outdoor and indoor for both species. Of the An. gambiae s.l. analysed, only An. gambiae sensu stricto (14.1%) and Anopheles coluzzii (85.9%) were found. The allelic frequencies of kdr and ace-1R were higher in An. gambiae (0.97 for kdr and 0.19 for ace-1R) than in An. coluzzii (0.86 for kdr and 0.10 for ace-1R) (P < 0.001). CONCLUSION: Despite universal coverage with long-lasting insecticidal nets (LLINs) in the area, there was an abundance of the malaria vectors (An. gambiae and An. funestus) in the study area in central Côte d'Ivoire. Consistent with high insecticide resistance intensity previously detected in these districts, the current study detected high kdr frequency (> 85%), coupled with high malaria transmission pattern, which could guide the use of Eave tubes in the study areas.
Authors: S Bhatt; D J Weiss; E Cameron; D Bisanzio; B Mappin; U Dalrymple; K Battle; C L Moyes; A Henry; P A Eckhoff; E A Wenger; O Briët; M A Penny; T A Smith; A Bennett; J Yukich; T P Eisele; J T Griffin; C A Fergus; M Lynch; F Lindgren; J M Cohen; C L J Murray; D L Smith; S I Hay; R E Cibulskis; P W Gething Journal: Nature Date: 2015-09-16 Impact factor: 49.962
Authors: Samir Bhatt; Daniel J Weiss; Bonnie Mappin; Ursula Dalrymple; Ewan Cameron; Donal Bisanzio; David L Smith; Catherine L Moyes; Andrew J Tatem; Michael Lynch; Cristin A Fergus; Joshua Yukich; Adam Bennett; Thomas P Eisele; Jan Kolaczinski; Richard E Cibulskis; Simon I Hay; Peter W Gething Journal: Elife Date: 2015-12-29 Impact factor: 8.140
Authors: Rosine Z Wolie; Alphonsine A Koffi; Ludovic P Ahoua Alou; Eleanore D Sternberg; Oulo N'Nan-Alla; Amal Dahounto; Florent H A Yapo; Kpahe M H Kanh; Soromane Camara; Welbeck A Oumbouke; Innocent Z Tia; Simon-Pierre A Nguetta; Matthew B Thomas; Raphael NGuessan Journal: Parasit Vectors Date: 2021-11-20 Impact factor: 3.876
Authors: Chris Bass; Dimitra Nikou; Martin J Donnelly; Martin S Williamson; Hilary Ranson; Amanda Ball; John Vontas; Linda M Field Journal: Malar J Date: 2007-08-13 Impact factor: 2.979
Authors: Welbeck A Oumbouke; Patricia Pignatelli; Antoine M G Barreaux; Innocent Z Tia; Alphonsine A Koffi; Ludovic P Ahoua Alou; Eleanore D Sternberg; Matthew B Thomas; David Weetman; Raphael N'Guessan Journal: Sci Rep Date: 2020-09-15 Impact factor: 4.379