A dead bird found in the Atwater area last month has tested positive for West Nile virus, Merced County officials announced Tuesday afternoon.
An American crow, found May 22, tested positive for the West Nile virus, according to a news release.
"It's the first evidence that West Nile virus is back in the county," said Allan Inman, director of the Merced County Mosquito Abatement District.
It's been a cause of concern for officials because the area where the crow was found -- outside of the Atwater city limit -- hasn't been the site of a West Nile outbreak recently, he said.
"It's been a number of years since we've taken the airplane over that area," he said of aerial surveying of potential problem spots. "We're still at risk because this is an area we haven't seen the virus in a couple of years."
Another cause of concern is that this case was reported about three months earlier than when the county reported finding evidence of West Nile in 2011.
The peak season for the virus for human cases is July, August and September, he said. But it wasn't until August 2011 that mosquitoes tested positive for the virus in the county, Inman said.
This week, the district began focusing on a two-mile radius around the area where the bird was found.
While flying over the area, he looked for standing water with vegetation in it. He spotted three draining basins from the air and half a dozen swimming pools people hadn't taken care of.
He set traps for mosquitoes and has sent some off for testing.
"No mosquitoes have tested positive for West Nile virus in the county (this year). But that could change any time this week," he said. "It takes only one bite by the right mosquito."
Last year, a 2-year-old horse with the West Nile virus died in Delhi. In 2010, the only person who became infected with the virus in Merced County died. In 2009, four human cases were reported and one of them resulted in a fatality.
It's recommended that people attending large outdoor events use insect repellent. They should also wear light-colored clothing to avoid attracting mosquitoes.
People are advised to wear long-sleeved shirts and pants, and to avoid being out during the first two hours of dusk and dawn because that's when mosquitoes are most active.
Residents are being asked to report any standing water on their properties to the abatement district.
The public can report dead birds to the California Department of Public Health at http://westnile.ca.gov/
report_wnv.php or by calling (877) 968-2473.
For more information on how individuals and families can protect themselves, please contact Inman at (209) 722-1527.
Reporter Ameera Butt can be reached at (209) 385-2477 or firstname.lastname@example.org.