Malaria Epidemiology across Rural and Urban Landscapes in Ethiopia

PROJECT 2 PROJECT SUMMARY Malaria Epidemiology Across Rural and Urban Landscapes in Ethiopia Although many rural areas of sub-Saharan Africa have achieved major reductions in malaria over the past two decades, the malaria burden is increasing in rapidly growing urban regions of the continent. Emergence of invasive Anopheles stephensi may further alter malaria transmission dynamics and increase malaria risk in urban settings. This application responds to the World Health Organization’s “Global framework for the response to malaria in urban areas,” a program launched in 2022 to address the challenges of urban malaria control in the context of An. stephensi invasion in Africa. The central objectives of this project are to advance knowledge of malaria epidemiology across the rural to urban continuum in Ethiopia, where invasive An. stephensi presents a major threat, and to examine the epidemiological impact of malaria vector control programs targeting areas at high risk for malaria and An. stephensi distribution. The central hypothesis is that An. stephensi invasion and rapid urbanization will modify malaria transmission dynamics and increase the risk of malaria infection and clinical disease. Deeper understanding of these processes will allow for the development of cost-effective malaria control strategies tailored to local urban vector ecology and risk patterns. Three specific aims are proposed: 1) Determine the temporal dynamics and spatial heterogeneity of malaria risk and underlying risk factors across the rural to urban continuum in Ethiopia; 2) Assess the impact of urbanization and An. stephensi invasion on malaria parasite within-host infection complexity and population-level genetic diversity; and 3) Evaluate the epidemiological impact and cost-effectiveness of a larviciding program targeting areas of high malaria risk in the rural to urban landscape. This project will reveal how An. stephensi invasion changes malaria risk and influences susceptibility to clinical malaria and will provide critical information on the cost- effectiveness of different microbial larviciding methods. Although this study will solely be conducted in Ethiopia, we anticipate that our findings will have broad and timely implications for the assessment of malaria risk and for malaria control in other African countries in the face of An. stephensi invasion.