Malaria Vector Surveillance, Prevalence, Diversity, Behavioural Patterns and Their Implications to Tourist Activities in Akwa Ibom State, Nigeria

Aims: Malaria poses a medical and public health challenge in Nigeria. The burden of the disease has
been a major source of concern to tourists in Uyo. Knowledge on the biting behaviour and the Human
Biting Rates (HBR) are needed to assess the epidemiology of the disease and in estimating the vector
- human contact.
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
households 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 Chain Reaction (PCR).
Results: Two anophelines species were collected by the sampling methods consisting of 21(23.3%)
Anopheles nili and 69(76.7%) Anophele 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: Better understanding of the behaviour of the sibling species within the complex is
important to help identify their roles in disease transmission and to facilitate vector control.