Vector Control Officials Caution Residents About Ticks and Tick-Borne Disease Transmission During Winter Months

Release date: 
Dec 6

Cotati, CA. -The Marin/Sonoma Mosquito & Vector Control District (District) is reminding residents that while ticks are active year-round, the adult western black-legged tick (Ixodes pacificus) is most prevalent in winter. This tick, also known as the deer tick, is commonly found fall through early spring in grassy, brushy, or wooded areas, especially along sides of trails. While this tick is the primary vector of Lyme disease, it also has the ability to transmit other types of tick-borne diseases.

The District lab staff collects western black-legged ticks and tests them for the presence of Borrelia burgdorferi, the bacterium that causes Lyme disease. 
"Our surveillance data shows on average 3% of the adult ticks we’ve collected have tested positive for the bacterium that causes Lyme disease," stated Kristen Holt, a biologist for the Marin/Sonoma Mosquito and Vector Control District. "This infection rate has remained fairly consistent over the past several years."
District officials recommend that residents always employ personal protection measures against ticks when outdoors. Additionally, pet owners should consult their veterinarians to discuss preventative measures that can be taken to protect their animals from ticks and tick-borne diseases.
Personal protection measures that should be taken before, during, and after being in tick habitat include:
  • Wear light-colored clothing with long sleeves and long pants when hiking, walking or working in areas where ticks may be present.
  • Pre-treat clothing and equipment with a permethrin product to kill ticks.
  • Apply a CDC recommended tick repellent such as DEET (at least 20% concentration) on exposed skin.
  • Tumble dry clothes in a dryer on high heat for 10 minutes to kill ticks after you come indoors.
  • Shower after being in tick habitat to detect ticks.
  • Remove ticks promptly by using tweezers to grasp the head of the tick as close to the skin as possible, then pull straight out.
  • Contact your physician if you have concerns or become ill after being bitten by a tick.
  • Visit to learn more about ticks and tick-bite prevention.