Plasmodium falciparum Sporozoite Rates in Anopheles gambiae s.l. at a University Teaching Hospital and Contiguous Village, Rivers State, Nigeria

Malaria is a major burden to human health in tropical and sub-tropical areas. In Nigeria, the entire population is at risk. Over the past decade, there had been persistent reports of mosquito nuisance and an increase in malaria prevalence at the University of Port Harcourt Teaching Hospital in lowland rainforest, Rivers State, Nigeria. It was therefore decided to obtain provisional malaria risk data, by determining the sporozoite rates of anthropophilic, endophlic and endophagic Anopheles gambiae s.l. in the hospital wards and rooms in the contiguous village. Standard keys and guides were used for mosquito identification and dissection to observe sporozoites in their salivary glands. More than half of all female Anopheles gambiae caught at the hospital had fed; similarly, 40.9% of Anopheles gambiae collected from the contiguous village had fed. The sporozoite rates were 75.0% and 73.29% at the hospital and the village respectively. These high sporozoite rates and the preponderance of endophilic, endophagic, anthropophilic An. gambiae s.l. among anophelines indicate high malaria risk at both sites. Since indoor residual spraying is not advisable in hospitals, physical (bed/outlet netting) and chemical (ITNs/LLINs) barriers and larval source management are the recommended alternatives.