Plasmodium falciparum infection rates for some Anopheles spp. from Guinea-Bissau, West Africa

<ns4:p> Presence of <ns4:italic>Plasmodium</ns4:italic> <ns4:italic>falciparum</ns4:italic> circumsporozoite protein (CSP) was detected by enzyme linked immunosorbent assay (ELISA) in a sample of <ns4:italic>Anopheles</ns4:italic> <ns4:italic>gambiae</ns4:italic> s.s., <ns4:italic>A. melas</ns4:italic> and <ns4:italic>A. pharoensis</ns4:italic> collected in Guinea-Bissau during October and November 2009. The percentage of <ns4:italic>P. falciparum</ns4:italic> infected samples (10.2% overall) was comparable to earlier studies from other sites in Guinea-Bissau (9.6-12.4%). The majority of the specimens collected were identified as <ns4:italic>A</ns4:italic> . <ns4:italic>gambiae</ns4:italic> which had an individual infection rate of 12.6 % across collection sites. A small number of specimens of <ns4:italic>A. coluzzii, A. coluzzii</ns4:italic> x <ns4:italic>A. gambiae</ns4:italic> hybrids, <ns4:italic>A</ns4:italic> . <ns4:italic>melas</ns4:italic> and <ns4:italic>A</ns4:italic> . <ns4:italic>pharoensis</ns4:italic> were collected and had infection rates of 4.3%, 4.1%, 11.1% and 33.3% respectively. Despite being present in low numbers in indoor collections, the exophilic feeding behaviors of <ns4:italic>A</ns4:italic> . <ns4:italic>melas</ns4:italic> (N=18) and <ns4:italic>A</ns4:italic> . <ns4:italic>pharoensis</ns4:italic> (N=6) and high infection rates observed in this survey suggest <ns4:italic>falciparum</ns4:italic> -malaria transmission potential outside of the protection of bed nets. </ns4:p>