Two dead birds found in Alamo week tested positive for West Nile Virus, Contra Costa Mosquito and Vector Control District officials announced Wednesday.
The dead American crows were discovered near the intersections of Stone Valley Road and Alamo Glen Drive on Aug. 4 and Camino Sobrante and Orinda Way last Sunday, district officials said.
There have now been three virus-positive dead birds found in the San Ramon Valley this summer, including one found in Blackhawk on July 31, according to the district.
In total, there have been 12 dead birds found in Contra Costa County this year that tested positive for West Nile virus, including cases reported in Brentwood, Concord and Antioch during the past week, district officials said.
"Taking precautions against mosquito bites wherever you are is important," Steve Schutz, scientific program manager with the district, said in a statement.
"While we are not surprised at the level of West Nile virus activity at this, the peak of the West Nile virus season, our surveillance system is clearly working to illustrate where the hot spots may exist," he added. "We have elevated our surveillance and control in these areas to alleviate risk of disease transmission and ask that residents take proper precautions against mosquitoes and their bites."
There were also mosquito groups in Byron and a flock of sentinel chickens near Holland Tract that tested positive earlier this month, according to district officials.
In all, the county has recorded 18 virus-positive tests among birds, mosquitoes and sentinel chickens, and no human cases have been reported in Contra Costa County to date this year.
Most cases of the virus in humans are mild and include symptoms such as fever, headache, tiredness, body aches and swollen lymph glands, according to district officials. Severe cases of West Nile virus can be fatal, as seen in 2006 when two people died from the disease.
To avoid being bitten by an infected mosquito, the district advises using mosquito repellents, dumping or draining standing water, staying indoors during dawn or dusk when mosquitoes are present, and reporting all dead birds and neglected swimming pools.
For more information, visit the district's website.