Evidence of Transmission of Plasmodium vivax 210 and Plasmodium vivax 247 by Anopheles gambiae and An. coluzzii, Major Malaria Vectors in Benin/West Africa

SIMPLE SUMMARY: For any country to achieve an effective malaria control program, the information on causative parasite diversity and dynamics in the region is a key factor. This study demonstrates that in Benin, the occurrence of malaria cases is not solely caused by Plasmodium falciparum (common malaria parasite) and involves other non-falciparum species. The aim of this work is to assess the prevalence of various Plasmodium species in locally collected mosquito cohorts, either through human landing catches or pyrethrum spray catches. Thus, the comparative data on the prevalence of circumsporozoite protein (CSP) antibodies of P. falciparum and P. vivax in Anopheles gambiae s.l., the major insect-vector responsible for transmitting the malaria parasite to humans in Benin, were reported. Further, to delineate the possible contribution of various Plasmodium species in malaria infection in collected mosquitoes, a molecular species-specific polymerase chain reaction analysis was performed. The important finding of this study reveals the variation in the distribution of Plasmodium species prevalence in Benin. The information incurred through this study will be very helpful for malaria control stakeholders as well as planning and management agencies designing effective diagnostics and preventive measures and treatments to curb the lethal impact of malaria in Benin. ABSTRACT: Current diagnostic and surveillance systems in Benin are not designed to accurately identify or report non-Plasmodium falciparum (Pf) human malaria infections. This study aims to assess and compare the prevalence of circumsporozoite protein (CSP) antibodies of Pf and P. vivax (Pv) in Anopheles gambiae s.l. in Benin. For that, mosquito collections were performed through human landing catches (HLC) and pyrethrum spray catches (PSC). The collected mosquitoes were morphologically identified, and Pf, Pv 210, and Pv 247 CSP antibodies were sought in An. gambiae s.l. through the ELISA and polymerase chain reaction (PCR) techniques. Of the 32,773 collected mosquitoes, 20.9% were An. gambiae s.l., 3.9% An. funestus gr., and 0.6% An. nili gr. In An. gambiae s.l., the sporozoite rate was 2.6% (95% CI: 2.1–3.1) for Pf, against 0.30% (95% CI: 0.1–0.5) and 0.2% (95% CI: 0.1–0.4), respectively, for Pv 210 and Pv 247. P. falciparum sporozoite positive mosquitoes were mostly An. gambiae (64.35%), followed by An. coluzzii (34.78%) and An. arabiensis (0.86%). At the opposite, for the Pv 210 sporozoite-positive mosquitoes, An. coluzzii and An. gambiae accounted for 76.92% and 23.08%, respectively. Overall, the present study shows that P. falciparum is not the only Plasmodium species involved in malaria cases in Benin.