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

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.

Presence of Plasmodium vivax in Anopheles gambiae and absence in other malaria vectors in Cove-Zagnanando-Ouinhi health zone in southern Benin, West Africa

“…Infection rates for P. vivax in vectors were high in this area, in contrast to previous work in the area according Osse et al [ 13 ] who found 1.5% for one commune in Agbangnizoun in the same region versus 5% in our three study communes. This is likely due to the use of PCR on whole mosquitoes for identification of parasites within the mosquitoes.…”

“…Overall, the highest infection rate of mosquitoes was observed with P. falciparum , followed by P. vivax (3.3%) and P. ovale (0.4%). These results are similar to those from the work conducted in Cotonou health zones by Poirier et al [ 25 ], and in Benin by Osse et al [ 13 ]. Detection of P. vivax infection had been reported in a large-scale study in asymptomatic subjects in Benin [ 13 , 25 ].…”

“…These results are similar to those from the work conducted in Cotonou health zones by Poirier et al [ 25 ], and in Benin by Osse et al [ 13 ]. Detection of P. vivax infection had been reported in a large-scale study in asymptomatic subjects in Benin [ 13 , 25 ]. This study was the first report of the infection of An.…”

“…This parasite is less the focus of public health considerations in terms of diagnosis, treatment or surveillance. As more sensitive diagnostic methods become available, P. vivax in Africa is increasingly reported by various types of survey (entomological, serological, community prevalence), as well as clinical data on infections of local residents and internationals [ 13 ].…”

“…ovale ) in surveyed children using microscopy [ 12 ]. In mosquitoes, a recent trial performed throughout Benin using ELISA and PCR techniques on mosquitoes found in mosquitoes of the Gambiae complex infected with both P. falciparum and P. vivax [ 13 ] in some of the 24 surveyed communes. It is, therefore, necessary to better understand the transmission dynamics of the different Plasmodium species in the different Anopheles vector species of malaria in different parts of the country.…”