The Effect of Climate Change on the Spread of Mosquito-Borne Diseases

One possible outcome of climate change is the spread of vector borne diseases. Warming temperatures can cause vectors to spread into more favorable environments, increasing the rate that mosquitoes and viruses reproduce, mature, and spread. A particularly important mosquito vector is Aedes aegypti, known as the “Yellow Fever” mosquito. We explored the temperatures at which Aedes aegypti can transmit Zika and dengue, predicted where in Oklahoma temperatures are suitable for Aedes aegypti to carry out this process, and determined the potential effects of temperature fluctuations due to climate change on transmission potential (days out of the year where R₀ > 0). Using daily temperature data collected by the Oklahoma Mesonet since 1999, we determined where there were suitable conditions for Zika and dengue transmission by Aedes aegypti by comparison with upper and lower temperature limits for each virus. Using downscaled climate projections developed by the Climatology Lab at the University of Idaho, we evaluated the average temperature shift throughout the state, determining a delta value, and added that to the current temperatures to analyze where the transmission potential for ZIKV and DENV could be in the years 2070 to 2099. For Zika transmission, it increased from 112 days to 136 days with RCP 4.5 and to 153 days with RCP 8.5. The number of days out of the year for dengue transmission increased from 171 to 191 days with RCP 4.5 and to 206 days with RCP 8.5.