Contra Costa County confirms first West Nile Virus positive dead bird of 2024

Mosquitoes will linger in Contra Costa as long as mild temps hang around
Once per week, residents should look for water collected from rain or sprinklers on their property. Even water inside a bottle cap could hold mosquito eggs. (Pete Cruz photo)

CONCORD, CA (Apr. 27, 2024) — The Contra Costa Mosquito and Vector Control District (District) reports the first dead bird of the year which has tested positive for West Nile virus (WNV) in Contra Costa County.

The dead bird, an American crow, was picked up in an area of Concord on April 9, 2024. The first WNV-positive dead bird from Contra Costa County comes after infected dead birds have also been reported from Alameda, San Mateo, and Santa Clara Counties.

“It is early in the season for the first detection of West Nile virus in Contra Costa County,” said Steve Schutz, Ph.D., Scientific Program Manager. “The last time the first dead bird of the year tested positive this early in the season was more than 10 years ago. With such early evidence of West Nile virus, it’s more important than ever for residents to take steps to reduce the risk of mosquitoes and mosquito bites.”

To reduce the risk of mosquitoes and WNV, the District recommends Contra Costa County residents dump and scrub. At least once per week, inspect front and back yards and dump out any amount of rain or sprinkler water that’s collected in any sort of container. This includes toys, tools, equipment, pet bowls, and trash. Even something as small as a water bottle lid could create a breeding space. Scrub the inside of each container to remove mosquito eggs that may stick to the container. Also, make sure window screens properly fit openings without gaps. Fix any rips or tears.

If you still experience mosquito issues on the property, Contra Costa County residents can contact the District to request mosquito service.

Use insect repellents

To reduce the risk of mosquito bites, the District recommends residents use EPA-registered insect repellents. It should contain one of the following active ingredients:

  • DEET
  • Picaridin
  • The repellent version of Oil of Lemon Eucalyptus
  • IR3535

Always follow the instructions on the label when using insect repellent. And report dead birds because dead birds are often the first sign of WNV in a particular location.

Contra Costa County residents can report dead birds by phone at (877) WNV-BIRD (968-2473) or online. County residents can also request mosquito service for residential property by calling (925) 685-9301 or online.