Climate, Control, and Resistance in Malaria Epidemiology: History and Mathematical Modeling

Friday, September 28, 2018 - 1:30pm to 2:45pm


Steffan Eikenberry
Arizona State University


Malaria is an ancient disease that accompanied the spread of agricultural civilization throughout history, and is caused by protozoan Plasmodia spread via Anopheles mosquitoes.  The lifecycles of pathogen and vector are sensitive to environmental conditions, and thus malaria primarily burdens the tropical regions of the world, especially sub-Saharan Africa, where control measures in the modern era have centered around insecticide spraying, insecticide-treated bednets, and drug treatment.  However, resistance in both vector and pathogen have undermined historical control efforts.  The last two decades have seen a massive scale-up of insecticide-treated bednets, with a large concomitant reduction in malaria mortality, but also the widespread emergence of insecticide resistance among mosquitoes with unclear implications for malaria epidemiology.  In this talk, this history is reviewed, and a new weather-dependent model for malaria transmission that includes the detailed dynamics of mosquito-bednet interaction is developed and parameterized from a large dataset.  Initial results suggest a highly nonlinear relationship between malaria transmission, insecticide resistance, and community-level bednet coverage, such that moderate resistance in the mosquito population may minimally affect epidemiology, but higher-level resistance could seriously undermine disease control.  The interaction between resistance and climate is also briefly explored, as are more sophisticated model extensions.