More mosquitoes test positive for West Nile Virus in Contra Costa County

From The Press
September 11, 2020

The Contra Costa Mosquito & Vector Control District (District) has confirmed three more groups of mosquitoes have tested positive for West Nile virus (WNV) in Contra Costa County. Two groups of mosquitoes were trapped in Brentwood and one group was collected in Discovery Bay. The positive mosquitoes from Brentwood were collected during District surveillance following last week’s Adult Mosquito Control efforts in Brentwood. Preliminary results suggest the treatment appears to have been effective, but the risk of WNV remains.

So far this year, a total of 11 groups of mosquitoes have tested positive for WNV in Contra Costa County. In past years, the District has confirmed WNV in mosquitoes well into October, so it’s important for county residents to remember, Labor Day is not the unofficial end of WNV season.

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