ROSEVILLE, Calif. – Four additional mosquito samples in Placer County have tested positive for West Nile virus (WNV) in the past two weeks, most occurring on the western border of the county.

“This increase of activity is not unexpected. It serves as a reminder that West Nile virus is still a threat and that we must take precautions to reduce our risk for exposure,” stated Joel Buettner, General Manager of the Placer Mosquito and Vector Control District.

Due to these test results, the District has scheduled a truck fogging for the early morning of August 5th in the following localized areas where the mosquito traps have turned up WNV-positive mosquitoes:

  • Elverta area – area north of Rio Linda Blvd to Jackson Road, between Brewer Road and Locust Road, and between Pleasant Grove Rd. and El Modena Ave.
  • West of Roseville – area between Fiddyment Rd. and Brewer Rd., north of Sunset Blvd to Catlett Rd.

Total mosquito numbers are still low according to Buettner, due to a combination of milder than usual temperatures and the District’s aggressive larval mosquito control program. Not seeing many mosquitoes may lead the general public to become more relaxed about practicing prevention strategies, but even with low mosquito numbers, the District warns that WNV transmission can still happen.

The Placer Mosquito and Vector Control 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

2011 Placer County West Nile virus activity update: 0 dead birds, 0 sentinel chickens, 5 mosquito samples, and 0 humans have tested positive for West Nile Virus to date.

Contact: Ada Barros, Public Information Officer (916) 380-5480.