West Nile Virus Surveillance

The District’s West Nile virus surveillance program reports several types of positive West Nile virus results, including dead birds, mosquito samples (“pools”), sentinel chickens, and human cases.

For more information about the District’s West Nile virus and mosquito population surveillance, visit the Mosquito Surveillance page.

For real-time West Nile virus data for California, visit the California Vectorborne Disease Surveillance Maps (CalSurv) page.

Map of California with counties outlined. Several counties are colored green, indicating West Nile virus activity in 2021

Current West Nile Virus Information for San Mateo County

As of June 30, 2021, there have been 165 dead birds reported in San Mateo County. Of those, 51 have been suitable for testing and all have tested negative for West Nile virus (WNV). No mosquito pools or sentinel chickens have tested positive for West Nile virus in San Mateo County in 2021.

West Nile Virus Dead Bird Hotline

The California Department of Public Health (CDPH) West Nile Virus Dead Bird Hotline is an important part of West Nile virus surveillance. Residents who find a dead bird in good condition should call 1-877-WNV-BIRD (1-877-968-2473) or file a report online. Although reports are only taken live during April to October, the District receives reports of dead birds year-round from CDPH and will collect…

West Nile Virus Season and Surveillance Efforts

Surveillance for West Nile virus began in California in mid-April. The District protects residents from this mosquito-borne disease with control that targets mosquitoes in the larval stage, mosquito population monitoring, disease surveillance and public education. The laboratory staff conducts surveillance to detect the presence of mosquito-borne disease in three main ways:

West Nile Virus, Previous Years' Data

For older or more comprehensive data, please contact us at info@smcmvcd.org

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