West Nile virus is back in Contra Costa County.

The first case of the year was found recently in a dead American crow in Brentwood, according to the Contra Costa Mosquito & Vector Control District.

Since 2005, 75 people in Contra Costa have been diagnosed with West Nile virus. Two people died from the disease in 2006.

The district said in a news release, “Certain birds carry WNV. Once a mosquito bites an infected bird, the mosquito can become infected. Mosquitoes can spread the virus when they bite another bird or person.”

To reduce the risk of the virus, the district recommends that Contra Costa County residents report dead birds because they are often the first sign of West Nile in a location.

The virus grows more efficiently when temperatures are consistently above 55 degrees. With hot daytime and warm overnight temperatures in the forecast, the district advises residents to reduce the risk by avoiding mosquito bites.

YouTube video
How reporting a dead bird helps track the spread of West Nile virus. (Video courtesy of California Department of Public Health/YouTube)

“Infected mosquitoes can spread West Nile virus to people through a single mosquito bite, but fortunately, the virus is easily preventable. With temperatures on the rise over the next several days, it’s important that Contra Costa County residents take precautions to avoid mosquito bites by using an effective insect repellent when outdoors, particularly around dawn and dusk. Wear long-sleeve shirts and long pants to reduce the amount of exposed skin that can be bitten. And avoid being outdoors where mosquitoes are present, if possible,” said Steve Schutz, the district’s scientific program manager.

The district advises people to dump standing water, as mosquitos can reproduce in something as small as a bottle cap full of water. Window screens should not have rips or tears and should fit properly in openings.

The Centers for Disease Control and Prevention says, when used as directed, U.S. Environmental Protection Agency-registered insect repellents are safe and effective. The district recommends using those with active ingredients, like DEET, picaridin or oil of lemon eucalyptus.

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