San Diego County officials confirmed that mosquitoes collected in the Rolando neighborhood have tested positive for West Nile virus (WNV), marking the first confirmed mosquito samples carrying the virus in the county since 2023. Additionally, four dead birds have also tested positive for WNV this year, though no human cases have been reported in San Diego in 2025.

While West Nile virus is primarily transmitted between birds and mosquitoes, it can infect humans, leading to symptoms such as headache, fever, nausea, rash, fatigue, or even severe neurological illness and death in rare cases.

The last major outbreak in San Diego occurred in 2015, when 44 residents were infected and six people died.

Los Angeles County residents should take note. Southern California’s warm summer weather creates ideal breeding conditions for mosquitoes. West Nile virus is often first detected in birds and mosquitoes before human cases emerge — making early prevention critical across the region.

Protect Yourself:

• Dump standing water weekly (e.g., flowerpots, buckets, clogged gutters).
• Wear long sleeves and pants during dawn and dusk.
• Use EPA-approved insect repellents like DEET.
• Ensure window screens are intact to keep mosquitoes out.

If you spot mosquito breeding sites or dead birds (especially crows, jays, hawks, or owls), report them to your local vector control agency. In San Diego, contact 858-694-2888 or email vector@sdcounty.ca.gov.

In LA County, report sightings to www.ReportMosquitoes.org or call 562-944-9656.