Abundance, host preferences and infectivity rates of malaria vectors in Badagry Local Government Area of Lagos, Nigeria

Abstract

The role of anopheles mosquitoes in malaria transmission was investigated in Badagry Local Government Area of Lagos,
Nigeria, between July-October 2004. A total of 1,800 female anopheline mosquitoes were collected indoors by human bait
and pyrethrum sprays in this coastal rainforest zone. Species identification morphologically and by polymerase chain reaction
(PCR) was carried out. ELISA was used to examine P. falciparium sporozoites-infected mosquitoes and their blood meal
origin. An.gambiae s.s (39%), An.funestus s.s (16.9%), An.moucheti nigeriensis (15.7%), An. arabiensis (11.7%) and An.
melas (10.2%) were identified. Sporozoite rate was 4.2 %, Human blood index (HBI) 67.3% and average monthly Entomological
Inoculation Rate (EIR) was 8.4 infective bites per person per month (ib/p/m) by human bait and 5.45 ib/p/m by pyrethrum
sprays. This study highlights the complex distribution of different species in the zone. The combined contribution of these
mosquito species to malaria transmission in this study highlights the inappropriateness of vector control strategies aimed at
one vector. This shows that diverse epidemiological situations have to be taken into account to control malaria.

Keywords: Malaria; vectors; Plasmodium falciparium ; transmission dynamics; Nigeria.

Nigerian Journal of Parasitology Vol. 27 2006: pp. 41-48