The Contra Costa Mosquito & Vector Control District announces that four more dead birds tested positive for West Nile Virus this week, with one found in Danville.
The other birds were found in Antioch, Concord, and Lafayette.
"Dead birds testing positive for West Nile virus indicates that virus is still active in the area," said Deborah Bass, public affairs manager for the District.
In August, an 83-year-old woman died from the virus in Stockton.
Several nearby counties have high infection rates at this time, Bass said in a release.
She explained that the dead birds found with the virus are a reminder for county residents to stay diligent by dumping out standing water and wearing mosquito repellent from dusk and into the evening.
Mosquitos are plentiful in August and September, which is most active time for the virus, he county said in a release.
Birds are the reservoir for West Nile virus. The two species of mosquitoes in Contra Costa County capable of transmitting the virus prefer to feed on birds; however, people can become infected when a mosquito bites an infected bird and then a person.
West Nile virus symptoms of the mild form include fever, headache, tiredness, body aches, and swollen lymph glands. While the illness can last only a few days, even healthy people have reported being sick for several weeks. West Nile virus of the severe form can be fatal.