West Nile Virus

West Nile Virus carrying mosquito

West Nile virus (WNV) is a mosquito-borne virus that causes disease in humans, horses, and birds. In nature, WNV cycles between mosquitoes (especially Culex mosquitoes) and birds. Mosquitoes become infected by biting infected birds. Mosquitoes infected with WNV can then bite and infect more birds or can bite and infect accidental hosts like people and horses. WNV can make people and horses sick and can even cause death.  

WNV It is the most prevalent mosquito-borne disease in the United States. It is established throughout the contiguous United States, and can be found in all 58 counties in California, including San Diego County

The Vector Control Program (VCP) monitors WNV by trapping and testing mosquitoes and by collecting and testing dead birds. VCP also protects public health by controlling mosquitoes that can transmit WNV, and by educating the public on measures they can take to keep themselves and their families safe from WNV and other mosquito borne diseases. 

The Vector Control Program encourages everyone to prevent mosquito breeding, protect themselves against mosquito bites, and to report green pools, dead birds, and high mosquito activity.


  (858) 694-2888