First West Nile positive dead bird found in 2026

First indicator of the virus circulating in Alameda County

 The Alameda County Mosquito Abatement District confirmed a dead bird collected in Newark has tested positive for West Nile virus (WNV), marking the first detection of the virus in Alameda County this year.

The bird was found in a residential area between Newark Boulevard and Christine Street. It was collected and tested at the District’s laboratory, and WNV was confirmed on Friday, May 1, 2026.

In response, the District is increasing mosquito surveillance and larval control efforts in the surrounding area. Staff are identifying and treating sources of standing water where mosquitoes can breed, including—but not limited to—ponds, sewers, storm drain systems, and unused swimming pools. Residents are encouraged to report unused pools or other standing water sources to the District so appropriate treatment can be applied.

“This spring, we’ve seen dramatic weather fluctuations, with significant rainfall followed by very warm days—conditions that are ideal for mosquitoes to develop in standing water,” said Ryan Clausnitzer, General Manager of the Alameda County Mosquito Abatement District. “We appreciate when members of the public report mosquito activity, and we follow up on all concerns throughout Alameda County. We encourage residents to reduce their exposure by eliminating standing water around their homes, wearing long sleeves and pants, and using insect repellent when mosquitoes are present. Residents should also report dead birds to the California Dead Bird Hotline: CA Dead Bird Hotline or 1-877-WNV-BIRD (1-877-968-2473) The most effective way to reduce mosquito habitats is to regularly drain, treat, or remove any areas where water can accumulate.”

Reduce your risk of mosquito-borne diseases by following these tips:

·     DUMP and DRAIN standing water around your home. Mosquitoes need water to complete their life cycle, without it they cannot mature to their adult stage.

·     DAWN and DUSK are peak mosquito activity times. Limit outdoor exposure during these hours.

·     DEFEND yourself by wearing long sleeves and pants, and using insect repellent containing EPA-registered ingredients such as DEET, picaridin, IR3535, or Oil of Lemon Eucalyptus.

·     Ensure DOOR and WINDOW SCREENS are in good condition with no tears or openings.

West Nile virus is transmitted to people and animals through the bite of an infected mosquito. About one in five people infected may experience symptoms such as fever, headache, body aches, joint pain, vomiting, or rash. Fewer than one percent of cases result in serious neurological illness, such as encephalitis or meningitis.

There is no cure for West Nile virus. Adults over 50 and individuals with weakened immune systems are at higher risk for severe illness. Anyone experiencing symptoms after mosquito exposure should seek medical care.

Horses are particularly susceptible to West Nile virus; however, vaccines are available. Horse owners should consult their veterinarians about appropriate vaccination schedules.

For more information about mosquitoes, West Nile virus, or to request District services, visit www.mosquitoes.org or call (510) 783-7744. Residents may also request mosquitofish for ponds, horse troughs, or unmaintained pools at the District office located at 23187 Connecticut Street in Hayward.

For information about West Nile virus symptoms, prevention, or testing, contact the Alameda County Public Health Department at (510) 267-8001.