Contra Costa County Records First Case of West Nile Virus This Year | News

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

“Infected mosquitoes can transmit West Nile virus to people through a single mosquito bite, but fortunately the virus is easily preventable. With rising temperatures over the next few days, it is important that residents of Contra County Costa take precautions to avoid mosquito bites by using effective insect repellent outdoors, particularly at dawn and dusk.Wear long-sleeved 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, district science program manager.

The district advises people to discard standing water, as mosquitoes can breed in something as small as a bottle cap filled with water. Screens should have no rips or tears and should fit snugly over the openings.

According to the Centers for Disease Control and Prevention, when used as directed, insect repellents registered with the US Environmental Protection Agency are safe and effective. The district recommends using those that contain active ingredients, such as DEET, picaridin, or lemon eucalyptus oil.

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