An American Crow found in late September in Belmont has tested positive for West Nile Virus, San Mateo County Mosquito & Vector Control District officials said Thursday.
In addition, a Hermit Thrush found in Foster City and a House Finch found in San Carlos have been deemed West Nile Virus chronic.
The crow was reported in Belmont on Sept. 27, county officials said. The House Finch was reported in San Carlos the same day, and the Hermit Thrush in Foster City on Sept. 26.
An animal that tests positive for West Nile Virus indicates a current infection (active viremia) that was acquired this season. One that is deemed West Nile Virus chronic indicates a low level of infection that was not acquired this season.
Both levels of infection will trigger deployment of C02 traps at the reported site and immediate neighborhood. In turn, the pool of mosquitoes collected are sent to the Center for Vectorborne Diseases Laboratory in Davis for WNV testing. So far, all mosquito pools tested for West Nile Virus this year have been negative.
Residents may report dead birds and squirrels to 1-877-WNV-BIRD.