The Placer Mosquito and Vector Control District reported today that a sentinel chicken has tested positive for West Nile virus antibodies. This is the first sign of increased West Nile virus activity in Placer County.  The chicken is part of a flock located in Roseville.  The District has two sentinel chicken flocks of six chickens each, with one placed in Roseville and one in Auburn.   Blood samples of each chicken are collected and tested every two weeks.  “Sentinel chickens are a useful surveillance strategy for two reasons. First, when an infected mosquito bites a chicken, it will not get sick, but it will develop antibodies toward the virus, which is something that we can easily test for.  Secondly, chicken flocks are static. This tells us that West Nile virus activity is occurring specifically in that area,” said Joel Buettner, General Manager.

Due to this latest development, the District has increased surveillance of larval and adult mosquitoes in the area.  The Placer Mosquito and Vector Control also advises the public to implement the 3 Ds of protection:

  • Drain or dump 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.

The District also encourages Placer residents to report dead birds, which are another useful tool in determining West Nile virus activity in an area.

2015 Placer County West Nile virus activity update: 0 dead birds, 1 sentinel chicken, 0 mosquito samples, and 0 humans have tested positive for West Nile Virus to date