Impact of climatic factors on entomological indices of Anopheles mosquitoes in Rivers State, Nigeria

Abstract

This study observed the effects of climatic factors on entomological indices of Anopheles species causing malaria in Rivers State. Indoor resident mosquitoes were caught using pyrethrum spray catch technique, and were identified morphologically. Female Anopheles mosquitoes’ salivary glands were assessed, stained in Giemsa and viewed using a compound microscope. The result showed that a total of 764 individual mosquitoes comprising 3 species: An. gambiae (s.l) 455 (59.55%), An. funestus, 224 (29.32%) and An. coustani, 85 (11.12%) were recorded. A total of 141 mosquitoes were infected with sporozoites giving an overall Sporozoite Rate (SR) of 18.82%. Anopheles gambiae (s.l) had the highest sporozoite rate (23.30%) followed by An. coustani (18.82%) and then An. funestus (8.48%). Man Biting Rate (MBR) in Odual was 7.81b/n/p and 12.22b/n/p in Port Harcourt; Entomological Inoculation Rate (EIR) was 161.71 ib/n/p and 206.76 ib/n/p in Odual and Port Harcourt respectively. The SR, MBR and EIR showed a positive linear correlation with humidity and rainfall but a negative correlation with temperature across the two stations.