County of Marin - News Releases - West Nile Virus

For Immediate Release
September 16, 2015

First 2015 Marin Case of West Nile Virus Confirmed

Novato man recovering at home from mosquito-borne illness

San Rafael, CA – A 57-year-old man from Novato is the first human West Nile virus case confirmed from Marin County for 2015, according to Marin County Health and Human Services. Public Health officials said the man is recovering at home.

A close-up view of a mosquito sitting on human flesh.It is unclear whether or not the man contracted the virus locally because of recent travel outside of the county. People 50 years of age and older have a higher chance of getting sick and are more likely to develop complications. Studies also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

According to the Centers for Disease Control and Prevention, West Nile virus is most commonly transmitted to humans by mosquitoes. There are no medications to treat or vaccines to prevent infection. Most people infected will have no symptoms. About 20 percent of those infected will develop a fever with other symptoms, and less than 1 percent develops a serious, sometimes fatal, neurologic illness.

As a part of the Marin Sonoma Mosquito and Vector Control District's (MSMVCD) Integrated Vector Management program, mosquito populations are closely monitored with control strategies implemented as necessary. Additional surveillance methods are being employed in the in the vicinity of the Novato resident’s home. MSMVCD officials are asking that residents report mosquito problems to the district immediately.

“West Nile Virus is endemic in Marin County, recurring every year during the summer and into the fall,” said Dr. Matt Willis, County Health Officer. "The best way to avoid West Nile Virus infection is to take precautionary measures to avoid mosquito bites.”

Vector Control and Marin HHS encourage residents to take the following safety precautions to protect against mosquito-borne diseases:

  • Report mosquito problems, neglected swimming pools, or any area that could be producing mosquitoes at or 1-800-231-3236.
  • Stock backyard ponds or other permanent water features with mosquitofish.
  • Be sure all window/door screens are in good repair.
  • 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.


Dr. Matthew Willis
Public Health Officer
Health and Human Services

3240 Kerner Blvd.
San Rafael, CA 94901
(415) 473-4163
Email: Dr. Matthew Willis
Marin HHS website