EL CERRITO, CA — Seven birds and a group of mosquitoes have tested positive for West Nile virus in Contra Costa County, with the majority of the activity in El Cerrito, health officials said Friday.
El Cerrito has been the site of only one previous positive bird test since the Contra Costa Mosquito and Vector Control District first found the virus.
"Finding four West Nile virus-positive dead birds in El Cerrito is significant because we have not previously detected this level of activity in the area," Dr. Paula Macedo, general manager of the district, said in a statement.
Mosquitoes typically become infected with West Nile after biting an infected bird. Dead birds are often the first sign of the virus in a particular location, according to the district.
District employees are setting traps in the area where the birds have been reported and performing inspections and treatment of known sources.
El Cerrito residents should put on mosquito repellent before going outside in the morning and evening, when mosquitoes are most active, the district said.
The district also recommended that Contra Costa County residents check their front and back yards at least once a week and dump out any standing water where mosquitoes can reproduce.
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