DDT behaviour studies / Indoor Residual Spraying (IRS) and Long-lasting Insecticide Treated Nets (LLIN): Integration of methods and insecticide mode of actions for control of African malaria vector mosquitoes.
Effective implementation of IRS and LLTNs are crucial to the success of the President’s Malaria Initiative, however, we do not know how these interventions can drastically reduce malaria transmission nor do we know the impact of incipient insecticide resistance. For Anopheles gambiae and other African malaria vectors we do not know the mode of action of the insecticides used for IRS and LLTNs. Studies suggest that IRS and LLTNs have similar impact at equivalent coverage levels; however, limited information is available to permit a data-based selection of one or a combination of these interventions. We hypothesize that different insecticides have different modes of actions, and that using pyrethroid contact insecticides for both IRS and LLIN simultaneously provides no added benefit relative to the use of one approach. We also hypothesize that complementing pyrethroid-treated ITNs with IRS of a spatial repellent (e.g., DDT or transfluthrin) will deliver benefits which are additive or even synergistic. It is postulated that development of resistance in vectors will change the efficacy of these interventions but no quantitative data exists to substantiate this hypothesis.
Additionally, the project's objectives are;
1. Construction of nine kit-form experimental huts based on local house design, adapted to facilitate research on mosquito entry, resting and exit behaviour. Baseline studies to describe natural entry and exit behaviour patterns of susceptible An. gambiae and evaluation of interception traps.
2. Chemical treatment of mud panels in experimental huts was performed to evaluate changes in vector behaviour in response to ICON CS, DDT and Actellic in combination with Olyset and Permanet in terms of reducing house entry, successful feeding, and survival of house entry and exit.
3. Insecticides commonly used for IRS in Tanzania and other PMI countries were evaluated alongside leading LLITNs, both singly and in combination to calculate the best strategy to provide both personal and household protection, at minimum financial outlay.
