Mosquito tests for the West Nile virus conducted last week were negative Thursday after a dead American crow in South San Francisco was found to have the virus.
The bird signaled the first indication of the West Nile virus in San Mateo County since 2018, according to the San Mateo County’s Mosquito and Vector Control District.
According to the report, the district used mosquito traps in the neighborhood where the dead bird was collected.
West Nile virus is mainly transmitted between birds by mosquitoes, which can then transmit the virus to humans. The virus cannot be transmitted from person to person. This makes the risk relatively small, said Megan Sebay of the district.
However, the district said residents should be vigilant and use best practices to avoid being bitten by a mosquito infected with the virus. Precautions include removing stagnant water that is a breeding ground for mosquitoes, wearing protective clothing at dusk and at dawn, when mosquito activity is highest, and applying a DEET-based repellant.
Residents are asked to report fresh bird carcasses to the California West Nile Virus Hotline at westnile.ca.gov or by calling 877-WNV-BIRD (877-968-2473).