ROSEVILLE, Calif. – Eight additional mosquito samples in Placer County have tested positive for West Nile virus (WNV) this week, the highest number of positive samples in one week since the beginning of the 2011 mosquito season.

Since the positive mosquito samples came from several of the mosquito traps along the western Placer County border, all the way from Sheridan to the Elverta area just west of Roseville, the Placer Mosquito and Vector Control District is gearing up for a larger-scale response to these results, with mosquito treatments in the rural areas beginning early next week. “We are still working out the details on how we will be conducting treatments across this large area, as well as increasing surveillance,” stated Joel Buettner, General Manager of the District.

According to Buettner, some localized treatments in residential areas of western Placer County were conducted early this morning. The District asks Placer County residents to consider the threat of West Nile virus and protect themselves accordingly this weekend.

The Placer Mosquito and Vector Control District advises the public to implement the 3 Ds of protection:

  • Drain any standing water that may produce mosquitoes.
  • Defend yourself and your home by using an effective insect repellent and dressing protectively when outside, and making sure screens on doors and windows are in good condition.
  • Contact the District for any additional help controlling mosquitoes around your home.

For more information, contact the Placer Mosquito and Vector Control District at (888) 768-2343 or visit Residents who would like to receive notification on adult mosquito treatments scheduled in Placer County may email

2011 Placer County West Nile virus activity update: 1 dead bird, 0 sentinel chickens, 13 mosquito samples, and 0 humans have tested positive for West Nile Virus to date.

Contact: Ada Barros, Public Information Officer,  (916) 343-0009