Impact of malaria control interventions on the infectious reservoir, host immunity, and drug resistance in Uganda
The goal of the project proposed here is to examine the effects of two key interventions, Indoor residual spraying (IRS) and treatment of populations with antimalarial drugs, on prevalence of low-level malaria infections (which are not detectable by standard malaria microscopy, but may contribute to transmission), measures of host immunity and the development of drug resistance. Further, considering sustainability, the impact of withdrawing the interventions on these same outcomes will be evaluated.
The impact of indoor residual spraying (IRS) alone or in combination with mass drug administration (MDA) will be investigated using data and samples from the Katakwi Rotary Malaria Project.
In Uganda, malaria control progress has been slow and control gains have been fragile, with increases in parasite prevalence being observed following cessation of implementation of effective control interventions. For improved control and ultimately elimination, interventions should be designed to eliminate reservoirs of malaria parasites, including microscopic and sub-microscopic infections, and yet minimize both the loss of host immunity, and the development of resistance.
The project proposed here will focus on the effects of IRS and MDA on sub-microscopic infections, host immunity and development of resistance, as well as the rebound effects of withdrawing the interventions on these markers. Understanding the impacts of these interventions will help to identify the optimal interventions to control and eliminate malaria in Uganda.
The researchers hypothesise that implementing IRS will lead to decreased prevalence of parasite infection, and adding MDA will be associated with a further decrease and sustained reduction in the prevalence, but with some loss of host immunity and increase in drug resistance compared to IRS alone. Findings from this study will guide decision making on how best to implement interventions to control and eliminate malaria in Uganda.