West Nile Virus in San Diego County 

mosquito larvae

West Nile virus (WNV) is a disease transmitted to humans, birds, horses, and other animals, by infected mosquitoes. Mosquitoes get the disease from feeding on infected birds and can later pass it on when they bite animals or humans.

WNV is established in San Diego County and can be found in all 58 counties in California! The virus was first isolated in the West Nile district of a Northern Province in Uganda in 1937. It was first detected in the United States in New York City in 1999. From there, the virus spread westward, arriving in California in 2003. West Nile virus is now the most prevalent mosquito-borne disease in the United States.

Learn more about West Nile virus here

The Vector Control Program protects communities and the environment by controlling mosquitoes that can transmit diseases to humans.

Vector Control Program staff monitor WNV by trapping, batching, and testing mosquitoes and by testing dead birds.

Current WNV activity is given below. Information for prior years is available here, and additional information on WNV can be found here

West Nile Virus Positive Finds map

Current WNV Activity

For more information on a specific source click on the source name (hyperlink) below

 Source  Number of Positives to Date (2020)
Birds 0
Mosquito Batches 2
Horses 0
Humans 1
Total Source Positives 3

SD Fight the Bite Homepage  

For More Information On 
WNV Or Other Vectors Contact: 
(858) 694-2888