VectorLink Madagascar Final Entomological Monitoring Report

The report was submitted to the United States Agency for International Development/PMI on August 31, 2021, and approved on October 18, 2021. The study was conducted in 13 sentinel sites across Madagascar, with a focus on monitoring the entomological aspects of malaria transmission. The sites were selected based on their high malaria transmission rates and the presence of Anopheles gambiae s.l., the primary malaria vector in the region. Vector bionomics monitoring was conducted at all sites, with a focus on adult mosquito collections, indoor resting density, outdoor collections, and vector density and behavior. The results showed that Anopheles gambiae s.l. was the dominant species at all sites, accounting for 70-90% of the total mosquito collections. The species composition of HLC-collected mosquitoes also showed a high prevalence of Anopheles gambiae s.l. Insecticide resistance monitoring was conducted using the WHO tube test, with a focus on Anopheles gambiae s.l. and other Anopheles species. The results showed that Anopheles gambiae s.l. was resistant to pyrethroids, with a high level of resistance recorded in 10 out of 13 sites. The resistance intensity was highest in the sites where the insecticide resistance monitoring was conducted. Cone bioassay results showed that the sprayed insecticides, Actellic 300 CS, SumiShield 50 WG, and Fludora Fusion WP-SB, had a fumigant effect on the mosquitoes. The results also showed that the residual efficacy of the insecticides was highest in the sites where the insecticides were sprayed. Molecular analysis was conducted to identify the species composition of the mosquitoes and to detect any genetic mutations that may be associated with insecticide resistance. The results showed that Anopheles gambiae s.l. was the dominant species, and that there was a high level of genetic diversity among the mosquitoes. The conclusions of the report highlight the importance of continued entomological monitoring to inform malaria control strategies in Madagascar. The results of the study show that Anopheles gambiae s.l. is the primary malaria vector in the region, and that there is a high level of resistance to pyrethroids. The report recommends the use of alternative insecticides and the implementation of integrated malaria control strategies that take into account the local ecology and the behavior of the mosquitoes. The report also highlights the importance of continued surveillance and monitoring to detect any changes in the mosquito population and to inform the development of effective malaria control strategies. The results of the study will be used to inform the development of a national malaria control strategy in Madagascar, and to guide the implementation of malaria control programs in the region.