DISCOVERY BAY — The number of birds and mosquitoes testing positive for the West Nile virus has increased by 50 percent in the past week, the county Mosquito & Vector Control District reported on Friday.
In the past week, there have been four groups of mosquitoes, four dead birds and one group of Sentinel Chickens that have tested positive for the West Nile virus. The discoveries have doubled the number of dead birds found with the virus in Contra Costa County for this year and nearly doubled the number of positive mosquito groups.
Usually, the months of August and September, when baby birds are leaving their nests and mosquitoes bite more often, are when the virus peaks, the district warned.
“As we enter the peak of West Nile virus season we’re starting to see more widespread activity,” said Steve Schutz, the district’s scientific programs manager. “People in all areas of Contra Costa County should be protecting themselves against mosquito bites.”
There have been 10 groups of mosquitoes, eight dead birds and 13 chickens from Contra Costa County that have tested positive for the virus this year.
There have been no reported cases of West Nile virus appearing in humans or horses in Contra Costa County this year, but there were four cases in 2017. In total, there was one horse, 19 dead birds, nine mosquito groups and seven chickens found with the virus in 2017.
Mosquitoes testing positive for the virus this year have been from Oakley, Martinez, Holland Tract, Discovery Bay and Quimby Island. Birds found with the virus have been from Brentwood, Discovery Bay, Antioch and Concord. Chickens from Holland Tract have also tested positive. This was the first West Nile virus activity for the year in Antioch, Quimby Island and Concord.
San Joaquin County has seen four cases of the virus in humans this year.
West Nile, a virus reported in all U.S. states, is spread to people by mosquito bites. Most people infected do not detect symptoms, according to the Centers for Disease Control and Prevention.
One in five develop a fever or other symptoms and one out of 150 have a serious or sometimes deadly illness, the CDC says. There is no vaccines to prevent it. Dead birds — often ravens, jays, crows and magpies – are often the first sign of the disease.
Mosquito & Vector Control District of Contra Costa said people should use mosquito repellents, drain pools or other standing water that mosquitoes feed on and report any dead birds to 1-877-968-2473 (1-877-WNV-BIRD).
To learn more, visit westnile.ca.gov
