Abstract: An entomological survey was carried out in selected rural communities in Oyo State Nigeria where entomological baseline data required for implementation and evaluation of vector control interventions is lacking. A total of 6806 Anopheles mosquitoes were collected in six rural communities out of which 10 Anopheles species were identified. An. gambiae, An. funestus and An. coustani were the only vector species that occurred in all the communities. Only two species: An. gambiae 2596 (38.1%) and An. funestus 3785 (55.6%) were found to be predominant. Polymerase Chain Reaction (PCR) analysis showed that An. gambiae s.s and An. arabiensis occurred in sympatry in all the communities while An. funestus s.s and An. leesoni occurred together in Oko Agric and Idi Ose. Cicumsporozoite (CSP) infection status of each Anopheles mosquitoes determined by Enzyme Linked Immunosorbent Assay (ELISA) showed that the Plasmodium falciparum sporozoite infection rates of An. gambiae s.s varied between 1.9 and 3.1% in the study communities as compared to 1.5 and 4.5% in An. funestus. Only one sample of An. arabiensis from Akufo community tested positive to the P. falciparun CSP antigen, all the other samples including An. leesoni tested negative to either P. falciparum or P. malariae. The annual EIR in Akufo, Ikere and Idi Ose were 139, 153 and 110 infective bites/ person/year, respectively with An. gambiae s.s contributing a higher overall transmission potentials when compared with An. funestus and An. arabiensis. This result shows the abundance of malaria vector species and their potential role in malaria transmission in rural communities.
A.O. Oduola, O.A. Otubanjo , J.B. Olojede , I.O. Oyewol and T.S. Awolola , 2012. Malaria Transmission Risk Indices of Three Anopheles Species in Selected Rural Communities in Oyo State South-Western Nigeria. International Journal of Tropical Medicine, 7: 42-48.