West Nile Virus Discovered in Thousand Oaks

A dead bird tested positive.

July 26, 2026 · Thousand Oaks

A dead bird collected in Thousand Oaks has tested positive for West Nile virus, the first confirmed detection in the city this year.

The bird was picked up July 2, with the positive result confirmed by the California Department of Public Health, the[Ventura County Environmental Health Division told The Acorn](https://www.toacorn.com/articles/west-nile-virus-detected-in-thousand-oaks/). The virus was first detected in the county this year in May.

The division said it will now inspect mosquito breeding sources near where the bird was found, and treat any locations where breeding is detected. The county currently tracks roughly 2,000 known breeding sites.

No human cases have been reported in Ventura County so far this year. As of July 17, just [two people statewide](https://lacounty.gov/2026/07/13/public-health-reports-first-human-case-of-west-nile-virus-in-los-angeles-county-for-2026/)—one in Sacramento and one in Los Angeles—had been reported with the virus.

Most people infected never develop symptoms, though about one in five experience flu-like symptoms. In rare cases the virus causes serious neurological illness, particularly in older adults and people with weakened immune systems.

Residents are urged to dump standing water, repair window screens, cover up at dawn and dusk, and use repellent.