Skip to main content

First Detection of West Nile Virus in Sonoma County in 2018

Cotati, CA. -The Marin/Sonoma Mosquito & Vector Control District (District) received confirmation from the UC Davis Arbovirus Research and Training Laboratory that a mosquito sample tested positive for West Nile virus (WNV). The group of mosquitoes was collected near the Ellis Creek Water Recycling Facility in Petaluma. 

"The test results and mosquito abundance surveillance data suggest an elevated risk for disease transmission in the area where the positive mosquitoes were collected,"  said Erik Hawk, Assistant Manager of the Marin/Sonoma Mosquito and Vector Control District. "It is extremely important that residents protect themselves from mosquito bites by employing personal protection measures such as wearing long sleeves and long pants, and applying an effective insect repellent to exposed skin." 

Repellents that contain an active ingredient which has been registered with the U.S. Environmental Protection Agency (EPA) have been proven to be most effective when applied according to the instructions on the label.  

District personnel will be conducting additional surveillance and control work in the area. Residents are urged to report stagnant water sources and mosquito problems to the Marin/Sonoma Mosquito and Vector Control District. 

Simple ways to help reduce exposure to mosquitoes and lessen the risk of WNV:

  • Check and maintain all window and door screens.
  • Report mosquito problems or any area that could be producing mosquitoes at or 1-800-231-3236.
  • Report dead birds to the West Nile virus hotline at 1-877-968-2473 or online at
  • Wear mosquito repellent when outdoors at dusk and dawn. Use a repellent containing one of the following active ingredients: DEET, Picaridin, oil of lemon eucalyptus, or IR3535.

Release Date: Oct 4, 2018

Join our mailing list