An updated report of Phlebotomine sand fly fauna from Kousseri, visceral Leishmaniasis focus in Northern Cameroon

Abstract

Data on the species composition of sand flies of Kousseri is out of date and there is no information on their role in disease transmission. In this context, a one-year survey, from September 2020 to August 2021 was conducted to update the species composition and detect Leishmania sp. infection in sand fly specimens. The checklist and distribution map of sand fly species from Cameroon are also mentioned. Sand fly specimens were collected monthly in five selected sites across Kousseri town using Centre for Disease Control and Prevention (CDC) miniature light traps. Only female specimens were morphologically identified to the species level based on valid diagnostic keys and tested for Leishmania donovani infection by polymerase chain reaction (PCR) targeting ITS1 at 350 bp using species-specific primers. A total of 2150 females were caught. Of these, eleven species belonging to three genera were identified: the genus Sergentomyia constituted 81.44% of collected sand flies versus 17.49% and 1.07% for the genera Grassomyia and Phlebotomus, respectively. To the best of our knowledge, this is the first report of Gr. inermis in Cameroon. Furthermore, five species including Se. clydei, Se. adleri, Se. schwetzi, Se. affinis vorax, and Gr. squamipleuris are herein listed for the first time in Kousseri. None of the female specimens tested for ITS-1 PCR were positive for Leishmania donovani infection. Further investigations are needed for a better assessment of the ecology of these sand fly species in order to provide reliable data for leishmaniases control and prevention in northern Cameroon.