Yellow fever is a mosquito-borne virus that is thought to cause between 20,000 and 180,000 deaths each year in Africa. Researchers have previously used environmental measures to map areas most at risk of yellow fever outbreaks, but the authors of a new PLOS Neglected Tropical Diseases study were interested in how the seasons might affect the disease’s spread.
Tini Garske of Imperial College London, U.K., and colleagues from Imperial and the World Health Organization incorporated seasonal variation in temperature, rainfall and vegetation in Africa into a new computer model to examine the effect of seasonal dynamics on mosquito behavior and virus transmission.
The authors’ seasonal model revealed geographic and temporal variations in yellow fever occurrence across Africa. It confirmed that even in geographic areas where risk of yellow fever transmission is relatively high, the precise risk varies throughout the year.
The researchers believe that, “when used in conjunction with forecasted data, the model predictions could be useful for focusing both surveillance efforts … and equipment in areas and periods of particularly high risk. This would allow the facilitation of early interventions in emerging yellow fever outbreaks.”