West Nile Virus Activity Update

Release date: 
Jul 11
Cotati, CA -  The Marin/Sonoma Mosquito & Vector Control District confirmed today that two dead birds and a mosquito sample have tested positive for West Nile virus. The two dead were both American crows; one collected near Spring Creek Road and Yulupa Avenue in Santa Rosa and the other near Haverfield Road and Magnolia Road in Petaluma. The positive mosquito sample was collected near Stonetree Lane and Harbor Drive in Novato. 
Residents are encouraged to take personal protection measures seriously and to apply these measures when engaging in all outdoor activities. Also, residents should perform a weekly check around their property and remove standing water. 
Ways to protect yourself from mosquitoes and West Nile virus: 
Reduce outdoor exposure to mosquitoes:
  • Limit outdoor activities during peak mosquito activity (dawn and dusk).
  • Properly use mosquito repellents containing DEET, picaridin, IR3535 or oil of lemon eucalyptus (always read the label carefully).
  • Wear protective clothing such as long sleeves and long pants.

Reduce indoor exposure to mosquitoes:

  • Keep doors and windows closed whenever possible.
  • Check and maintain all window and door screens.

Prevent mosquitoes from breeding near your home:

  • Flip, dump or drain all temporary sources of standing water.
  • Check septic tank lids to ensure a tight seal and repair any visible cracks.
  • Screen septic tank vent pipes using a fine mesh screen.
  • Eliminate standing water in rain barrels, old tires, buckets, kiddie pools or any other item that can hold water for more than a week.
  • Stock backyard ponds or other permanent water features withmosquitofish. The fish are free and can be delivered or simply picked up at the District office.
  • Call Marin/Sonoma Mosquito & Vector Control District if you have a mosquito-related problem that you cannot resolve on your own.

Report dead birds:

  • Reporting dead birds can help the District detect West Nile virus activity. 
  • Click here to watch a short video about what to do if you find a dead bird. 
  • Residents who find dead birds are encouraged to report them to the West Nile virus hotline at 1-877-WNV-BIRD or online at  www.westnile.ca.gov.

Stay Informed:

  • Residents interested in staying informed about District activities are encouraged to follow MSMVCD on twitter and facebook.  

West Nile virus is a mosquito-borne disease that is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the disease to humans and other animals.


Click here to learn more about West Nile virus activity in Marin and Sonoma counties for 2014.


Less than 1% of people (1 in 150) infected with WNV develop serious illness. These cases may last for extended periods of time, result in permanent neurological damage and may be fatal. Approximately 20% of people (about 1 in 5) infected with WNV experience mild symptoms that may include fever, headache, body aches, nausea, rashes, swollen lymph nodes and vomiting. Approximately 80% of people (about 4 out of 5) infected with WNV do not show any symptoms.