Abstract

*Ukwa O. Orji, Akin A. Adegoke, Ladoja M. Rafin, Fayemi D. Dorcas and Ogun A. Ola

Malaria is a problem in Nigeria and the risk exists throughout the country. Anopheles mosquitoes have been incriminated as the major malaria vectors. Vectors competence, however, differs from one species to another and from place to place. The present study reports the species abundance, composition and vectoral competence of Anopheles species in six areas of Lagos in Nigeria. The human blood index (HBI) and sporozoite rates (SR) were the components of vectoral competence. Human landing catches was used in collection. Species identification morphologically and by polymerase chain reaction (PCR) was carried out on mosquitoes. Enzyme linked immunoarsorbent assay (ELISA) was used to examine – sporozoite infected Anopheles and their blood meal origin. Anopheles gambiae s.s. was found to be most widespread and competent vector in all the six areas. The highest proportions of female Anopheles caught were from Alimosho area (49.8%), but they were mainly with no blood meal (47.9%). In Ajeromi, 85.7% of the female Anopheles had blood meals. Anopheles in Agege area, however, had the highest HBI. Sporozoite rate was highest in Mushin but lowest in Agege. The other Anopheles species were less relatively competent compared to Anopheles gambiae s.s, Anopheles funestus s.s was the second predominant and competent vector in all the areas. Anopheles moucheti nigeriensis was collected from Ajeromi and Amuwo Odofin areas alone and carried sporozoites in the two areas. Ojo area was identified as the most endemic because of the HBI 61.6% and SR of 62.9%. The present study has provided baseline data for formulating control programmes in Lagos State, Nigeria.