Los Angeles health officials have issued a statement urging the public to take precautions against mosquitoes after crows in the county tested positive for the West Nile virus. "These findings are a clear warning that the virus is continuing to circulate and amplify in the environment. Now is the time to take precautions," said Steve West of the San Gabriel Valley Mosquito and Vector Control District.
The detection of West Nile virus (WNV) in Los Angeles and Orange counties marks the first evidence of the virus in California this year, State Health Director Sandra Shewry announced today. In Los Angeles County, the virus was confirmed Thursday in a dead crow collected from the San Gabriel Valley. Orange County vector control and health officials announced yesterday that antibodies to WNV were detected in two local house finches.
"West Nile virus has been detected earlier than expected this year, probably due to unseasonably warm weather," Shewry said. "The state's surveillance system is closely monitoring for any evidence of the virus across the state. West Nile virus infection has not been detected in humans this year."
The state's interagency surveillance system for WNV includes testing of dead birds, mosquitoes and sentinel chickens. The dead bird surveillance program is coordinated by the California Department of Health Services (CDHS). The WNV positive dead crow was reported to CDHS by a resident on Feb. 24 and picked up by the San Gabriel Valley Mosquito and Vector Control District. The crow was shipped to the California Animal Health and Food Safety Laboratory for initial processing before being tested at the University of California, Davis, arbovirus diagnostic laboratory. Test results were confirmed today.
Shewry encouraged the public to report birds that have been dead for less than 48 hours to CDHS’ toll-free hotline: 1-877-WNV-BIRD. The public can report dead crows, ravens, magpies, jays, sparrows, finches and raptors to the hotline. Individuals should take note of the bird’s location and its condition before calling for further instructions, including assistance with identifying the type of bird found. The bird should show no signs of decomposition or maggot infestation. While there is no evidence that people can get the virus from handling live or dead infected birds, individuals should not attempt to catch or handle them. "We are calling on the public to provide us with information about dead birds so we can detect movement of the virus in order to protect the public health," she said.