Ten more birds tested positive for West Nile virus, bringing the total number of infected birds to 25 this year. Four groups of mosquitoes have been reported carrying the virus as well, district spokeswoman Deborah Bass said.
The 10 infected birds were collected from Walnut Creek, Pleasant Hill, Concord, Lafayette and Brentwood, Bass said.
Dead bird reports are an important tool to detect the West Nile virus and higher risk areas, according to Bass.
People can report dead birds by calling the state's West Nile virus hotline at (877) 968-2473 or visiting www.westnile.ca.gov.
