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First Detection of West Nile Virus for 2021

Cotati, CA. July 6, 2021-The Marin/Sonoma Mosquito & Vector Control District (District) has confirmed finding the first dead bird infected with West Nile virus for 2021. The American Crow was collected near Country Club Drive and Piezza Road in Santa Rosa and is the first detection of West Nile virus activity for the 2021 season.

 “Mosquitoes that feed on West Nile virus infected birds can become infected with the virus, and then transmit it to humans” stated Dr. Kelly Liebman, Scientific Programs Manager for the Marin/Sonoma Mosquito and Vector Control District. “This infected bird is a reminder that West Nile virus is present in our communities, and that residents should continue to practice personal protection measures against mosquitoes.”

District staff will continue to trap, test, and monitor the abundance of adult mosquitoes in the area and perform control operations as necessary. Vector control technicians are also inspecting all known local sources of mosquito production and checking for new sources.

   The Marin/Sonoma Mosquito and Vector Control District, in accordance with the California Department of Public Health, recommends repellents that contain one of the following active ingredients:

  • DEET
  • Picaridin
  • Oil of lemon eucalyptus 
  • IR3535
  • Para-menthane-diol (PMD)

Other ways to protect yourself from mosquitoes and mosquito bites include:

  • Stock permanent water features with mosquitofish (available free from the District)
  • Be sure to properly screen and/or secure lids on rain barrels or water storage containers
  • Do not over-water lawns
  • Clean out bird baths and animal water bowls at least twice a week
  • Keep swimming pools and hot tubs properly chlorinated
  • Make sure that septic tank lids are properly sealed and vent pipes are screened
  • Report mosquito problems at 707-285-2200 or online at
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