Morphological and Molecular Characterization of Anopheles Mosquitoes and Their Behavioural Patterns in Uyo, Nigeria

Abstract

Aims: Malaria is a public health problem in Nigeria. Knowledge of some baseline data such as Human Biting Rates (HBR) is needed to assess the epidemiology of the disease and in estimating the vector-human contact. This study provides information on the behavioural patterns of anopheles mosquitoes in Uyo.                                                                                                   Study Design: A six months study was carried out in Uyo, Nigeria where no information exists on the major malaria vectors associated with human malaria. Sample collection was carried out between May and October 2013 using Knockdown and Human Landing Catches (HLC) techniques. Methodology: Adults mosquitoes were collected in two areas in Ewet Offot Community. Nine houses were randomly selected in each location using Simple Random Sampling Method. Mosquitoes belonging to the Anopheles gambiae complex were further characterized and identified by a molecular method using Polymerase Chaiin Reaction (PCR). Results: Two anophelines species were collected by the sampling methods consisting of 21(23.3%) Anopheles nili and 69(76.7%) Anopheles gambiae complex. A Polymerase Chain Reaction (PCR) based test on the An. gambiae complex identified 66(96.0%) as An. gambiae sensu stricto. The study also revealed that the resting behaviour of An. gambiae complex species in this area is endophilic whereas the resting behaviour of An. nili is exophagic/exophilic. The peak biting activity of An. gambiae complex species occurred at 11 pm (indoor) and 7 pm (outdoor) in July whereas that of An. nili occurred at 10 pm (indoor) and 6 pm (outdoor) in June. The Human Biting Rates (HBR) recorded for An. gambiae was higher than An. nili and the total number An. gambiae collected was more than An. nili. Conclusion: There is a need for a comprehensive knowledge on the behaviour and heterogeneities that exist within and among malaria vector species in this area if the goal of malaria elimination is to be achieved.