Jovin Kitau

University

Kilimanjaro Christian Medical College, Moshi (KCMC).

PhD Title

Behavioural responses of malaria vectors to insecticides and repellents and the subsequent effect on malaria control.

Abstract

Mosquitoes are becoming increasingly resistant to all categories of insecticides. An alternative approach to malaria prevention is to use repellents. However the effectiveness of repellents is disputed owing to the ephemeral protection of topical repellents, their varying efficacy against different mosquito species, the need for regular re-application and causing diversion to non-users who receive more bites. Nevertheless the role of repellents has been underestimated because the effect of the chemical on mosquitoes is easily misinterpreted. Acting primarily as space repellents rather than toxins, some chemicals (e.g. DDT) may appear to be effective through toxicity whereas in fact behavioral avoidance or spatial repellency from the chemicals may drive mosquitoes away from human hosts leading to death through starvation. Resolving the debate over spatial repellency and chemical toxicity is therefore paramount in determining how chemicals function to reduce human-mosquito contact and prevent malaria transmission. Additionally, this will provide a proof of concept of spatial repellency in malaria control. Through a series of laboratory, semi-field experimental structures and community studies to be done in Kilimanjaro and Tanga regions, this study intends to determine behavioral responses of malaria vectors to insecticides and repellents and the relative value of these responses on malaria control.