The first confirmed cases of West Nile virus (WNV) in Orange County for 2025 have been detected in mosquitoes and a dead bird found in Anaheim and Garden Grove, according to the Orange County Mosquito and Vector Control District (OCMVCD). This signals active virus circulation in historically high-risk areas.

Positive mosquito samples were collected from four locations, including areas near Euclid Avenue and the 5 Freeway in Anaheim, and near Brookhurst Street and Garden Grove Boulevard in Garden Grove. A dead bird in Garden Grove also tested positive.

Although no human cases have been reported in the county yet this year, WNV is already affecting other parts of the state. As of July 18, California has confirmed 680 WNV-positive mosquito samples, 51 infected birds, and three human cases — in Tulare, Stanislaus, and Kings counties.

West Nile virus is spread through the bite of infected Culex mosquitoes, which become carriers after feeding on infected birds. While most people do not develop symptoms, about 1 in 5 may experience fever, headache, and body aches. Severe neurological illness is possible, especially in older adults and immunocompromised individuals.

Prevention Tips:

• Dump and drain standing water at least weekly
• Clean bird baths and pet water bowls regularly
• Use repellents with DEET, Picaridin, IR3535, or oil of lemon eucalyptus
• Repair window screens to keep mosquitoes out
• Wear long sleeves at dawn and dusk

Find more information at: westnile.ca.gov