Adult Mosquito Sample from Southeast Petaluma Tests Positive for West Nile Virus

Release date: 
Oct 25

Cotati, California- The Marin/Sonoma Mosquito & Vector Control District (District) announced today that an adult mosquito sample from the vicinity of the Ellis Creek Water Recycling Facility has tested positive for West Nile virus.

Adult mosquito control is scheduled to occur in the area this evening- weather permitting. In addition, larval mosquito control is scheduled for tomorrow (October 26, 2011), and District surveillance efforts will increase. Informational signs will be posted along the walking trails at the water recycling facility.
Residents are urged to protect themselves from mosquitoes by following these simple tips:

  • Be aware that mosquitoes are most active between dusk and dawn.
  • When outdoors, wear long-sleeved shirts, long pants, and apply insect repellent according to label instructions. Repellents containing the active ingredient DEET, Picaridin or Oil of lemon eucalyptus are most effective.
  • Screen all windows and make sure existing screens are in good repair.
  • Cover septic tanks and screen roof vent pipes.
  • Identify and eliminate all sources of standing water around your property.

For more information or to report mosquito problems visit the District’s website at
Recent West Nile virus activity in Marin and Sonoma counties
2011: 2 mosquito pools
2010: No West Nile virus activity
2009: No West Nile virus activity
2008: 2 mosquito pools and 12 dead birds
2007: 1 human, 2 horses, 23 dead birds, 1 mosquito pool
2006: 1 human, 2 horses, 29 dead birds, 5 mosquito pools, 3 sentinel chickens, 1 dead squirrel
2005: 1 human, 1 horse, 92 dead birds
2004: 1 horse, 67 dead birds, 1 mosquito pool
The Marin/Sonoma Mosquito & Vector Control District is an independent, special district committed to protecting public health from mosquitoes and mosquito-borne disease. All programs and services are funded through property taxes and provided to all residents in Marin and Sonoma counties. For more information about us please visit our website at