ROSEVILLE, Calif. – More mosquito samples and an additional dead bird in residential areas of west and northwest Roseville have turned up positive for West Nile virus.

To date, Placer County has seen increased West Nile activity in the mosquito and bird populations, as well as a recent human case. “Although we are not yet at epidemic levels of the virus according to the California Department of Public Health criteria, there clearly continues to be significant WNV in western Placer County” stated Joel Buettner, General Manager of the Placer Mosquito and Vector Control District. In response to the high levels of viral activity this year, the District has done more adult mosquito treatments this year than any other year since its establishment.

“West Nile virus season is far from over, even with the change in weather. It is important that residents continue to employ preventive measures against West Nile and other mosquito-borne diseases until the threat has subsided,” adds Buettner.

Due to this latest development, the District has scheduled ground-based adulticide applications for the early morning of September 10 in the following area of Roseville:

  • Western City limit of Roseville, between Pleasant Grove Blvd north to Blue Oaks drive, east to Woodcreek Oaks Blvd.

Since several factors affect spraying activities, such as weather and wind conditions, the District encourages Placer residents to check the District website at for any changes to the spraying schedule.

With West Nile virus spreading to more populated areas of the county, 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, 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, or to report potential mosquito breeding sources, such as neglected swimming pools.

For more information, contact the Placer Mosquito and Vector Control District at (888) 768-2343 or

2010 Placer County West Nile virus activity update: 6 dead birds, 2 sentinel chickens, 33 mosquito samples, and 1 human have tested positive for West Nile Virus to date.

Contact: Ada Barros, Public Information Officer