First Sign of West Nile Virus in Sonoma County in 2015

Release date: 
May 15
Cotati, CA.-The Marin/Sonoma Mosquito & Vector Control District (MSMVCD) has confirmed finding the first dead birds infected with West Nile virus (WNv) in 2015. Two dead American crows were collected from Windsor, in the vicinity of Gumview Road. 

"As we enter another year plagued by drought, the District is concerned about a potential increase in West Nile virus activity," stated Nizza Sequeira, Public Relations Director for the Marin/Sonoma Mosquito and Vector Control District. "During a drought, large numbers of both mosquitoes and birds congregate near limited water sources, thus increasing the probability of virus transmission," stated Sequeira.


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 inspecting the area for unknown sources of mosquito production as well as checking all existing sources.


Residents are urged to continue to report mosquito problems in their area and to reduce mosquito production sites in their yards by removing standing water on a regular basis. Additionally, residents should use personal protection measures against mosquito bites. Wearing long sleeved shirts, long pants and applying an effective repellent to exposed skin will help reduce the risk of WNv transmission from an infected mosquito.


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

  • Report mosquito problems or any area that could be producing mosquitoes at or 1-800-231-3236.
  • Stock backyard ponds or other permanent, contained water features with mosquitofish.
  • 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.