The Contra Costa Mosquito and Vector Control District confirmed Friday two dead birds from Danville and Alamo, as well as two from Pinole and Concord, tested positive for West Nile virus.
In addition a group of mosquitoes from Discovery Bay and a chicken from Holland Tract tested positive for the virus. All 2014 West Nile virus activity can be found at the district's website online.
"It's summer and you know what that means," said the district's public affairs manager Deborah Bass. "Mosquitoes and repellent go hand in hand. Or at least they should."
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. If severe, West Nile virus can be fatal.
To reduce the risk of contracting mosquito-borne diseases, follow these guidelines:
* Report dead birds to the state hotline 1-877-WNV-BIRD (1-877-968-2473) or at the California West Nile virus website
* Dump or drain standing water. Mosquitoes can't begin their life without water.
* Defend against mosquito bites by using repellents containing DEET, Picaridin, or Oil of Lemon Eucalyptus.
* Avoid being outdoors when mosquitoes are present, typically dawn and dusk.
* Report neglected swimming pools by calling 771-6195 or visiting the CCMVCD website Anonymous calls accepted.
Fogging for adult mosquitoes in Discovery Bay was scheduled for Friday night