Exploratory studies of Anopheles species abundance in five selected communities of Emohua LGA, Rivers State

Abstract

Malaria is one of the public health problems facing people in many parts of Nigeria. To effectively implement malaria control program, baseline studies of species abundance and their susceptibility status to insecticides is required. The aim of the study was to carry out baseline studies on malaria vectors, species abundance and susceptibility status of local malaria vectors in five communities in Emohua Local Government Area of Rivers State. Mosquito larvae were collected from different breeding sites, reared in the insectary and identified morphologically. Data collected were analyzed using SAS software and statistics software GraphPad Software. Spearman’s rank correlation coefficient (RHO) was used in comparing Indoor Resting Density (IRD) and Man Biting Rates (MBR). A Total of 1,415 adult indoor mosquitoes were caught comprising of two (2) genera. Of these, 87.21% were Anopheles gambiae s.l. and 12.79% were Culex spp. There was a statistical difference (p<0.0001) in the distribution of Anopheles and Culex mosquitoes caught. The highest percentage of Anopheles mosquitoes were caught at Emohua 26.74%, followed by Rumuji 22.77%, Egbeda 21.96%, Akpabu 17.10% and the least was Elele 11.43%. Examination of their abdominal conditions to determine feeding frequency indicated that the average number of fed mosquitoes ranged from 0.17-15.13 with a peak of 15.13 in the month of September in Elele. There was a significant difference (p<0.0001) in Indoor Resting Density (IRD) and Man Biting Rate (MBR) in the area. This study has contributed to the understanding of the distribution, composition and indoor resting behaviour of mosquito vectors in the study areas.