Cartography of permethrin resistance in malaria vectors from 2008 to 2020 in the Republic of Benin, West Africa

Abstract

The use of chemical insecticides causes important damage to the environment and human health and there is a need to monitor it.The current study aimsto establishthe cartography of permethrin resistance in malaria vectors from 2008 to 2020 in the Republic of Benin. Larvae of An. gambiae s.l. were collected from March to July during the great rainy season in Ouémé in 2008 and in 2012, Littoral in 2008, Mono in 2014 and in 2018, Couffo in 2020, Zou in 2008 and in 2012 and Collines in 2013. Larvae of An. gambiae s.l. were also collected from May to October during the rainy season in Alibori in 2012. Susceptibility tests were done following WHO protocol on unfed female adult mosquitoes aged 2-5 days old reared from larval and pupal collections with papers impregnated with permethrin (0.75%). The results showed that the populations of anopheles gambiae s.l. from Akron, Suru-léré, Bamè, Ladji and Houéyiho were resistant to permethrin in 2008, whereas the populations of Anopheles gambiae s.l. from Agbalilamè, Parakou and Bohicon were resistant to permethrin in 2012. The populations of Anopheles gambiae s.l. from Savè were resistant to permethrin in 2013. The populations of Anopheles gambiae s.l. from Grand-Popo, Comè and Lokossa were resistant to permethrin in 2014, whereas the populations of Anopheles gambiae s.l. from Houéyogbé and Bopa were resistant to permethrin in 2018. The populations of Anopheles gambiae s.l. from Dogbo were resistant to permethrin in 2020.