It is estimated that approximately 40% of the world's population lives in regions at risk for dengue virus transmission. Annually, this virus infects between 50-100 million people, causing approximately 22,000 deaths worldwide. Dengue is endemic in the tropics and subtropics where the climate is generally warm enough for the virus to develop successfully within the key mosquito vector, Aedes aegypti, but what aspects of temperature are important for transmission?
In collaboration with Professor Thomas Scott of the University of California, Davis, Penn State CIDD Professor Matthew Thomas and his team evaluated what effect daily fluctuations in temperature have on the transmission of this virus. They showed that mosquito life span and susceptibility to dengue infection decreases when there are larger fluctuations in daily temperature as compared to only moderate daily temperature variations. These results help to define the characteristic seasonal variation in dengue transmission observed in parts of Thailand, in which dengue virus transmission is high during seasons with more moderate daily temperature fluctuations and low in seasons with larger temperature fluctuations.
This research builds on previous work on malaria and highlights the importance of considering environmental drivers of transmission at the appropriate resolution for the vector and parasite; in this instance, transmission depends on daily temperature variation and not simply the mean conditions.
Synopsis written by Alexia Karanikas.
Written By: Lambrechts L, Paaijmans KP, Fansiri T, Carrington LB, Kramer LD, Thomas MB, & Scott TW
Paper Url: http://www.pnas.org/content/108/18/7460.full
Journal: 108: 7460-7465
Journal Reference: 108: 7460-7465
Paper Id: 10.1073/pnas.1101377108