Drought Conditions in California Cause Increased Prevalence of West Nile Virus

FAIRFAX, Va. (September 29, 2014) – An historic drought in California is thought to be the cause of a stark rise in the number of West Nile virus infections. This year, there have been twice as many infections as were reported in the same time period last year. West Nile virus is spread by mosquitoes that contract the virus from infected birds. Because there is less water available, birds and mosquitoes are being drawn to the same few water sources. Mosquitoes will therefore spread the infection to more birds than usual, accelerating the cycle. 

In addition, existing water sources are more likely to be stagnant, resulting in ideal habitats for mosquito breeding. The warm temperatures still present in California are also helping to accelerate mosquito development. Residents are advised to keep an eye out for stagnant water and to dump it out to prevent mosquito breeding grounds from forming near human residences.