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Lyme Disease

Though Orange County has not had any confirmed locally acquired human cases of Lyme disease, the District routinely tests for the presence of the Lyme disease in local tick populations. Lyme disease is caused by a spirochete (a corkscrew- shaped bacteria) called Borrelia burgdorferi and is transmitted by the western black-legged tick in California. Lyme disease was first described in North America in the 1970s in Lyme, Connecticut, the town for which it was then named. This disease has since been reported from many areas of the country, including most counties in California. The Orange County Mosquito and Vector Control District (District) has tested nearly 3,000 black-legged ticks since 1988 and only one was positive for Lyme spirochaetes.

Ticks are arachnids related to spiders and mites. They attach to wild animals, pets, and people using complex mouthparts resembling a "harpoon". While they are attached, they suck blood for several days, dropping off once engorged.

General Information


Picture of different ticks

How Ticks Find Their Hosts

They are found near the ground waiting for a host. They often climb onto tall grass or plants to snag onto passing animals or humans. They have sensory organs in their legs that detect carbon dioxide, odors, and heat given off by warm blooded animals. When an animal is detected, ticks crawl to the tips of vegetation and use their barbed front legs to snag onto the animal. This behavior is called "questing". Ticks cannot jump or fly.

Tick Removal

Ticks feed by inserting their mouthparts into the skin and taking a blood meal. Removing ticks promptly can prevent transmission of Lyme disease and other tick-borne diseases. If ticks are removed less than 24 hours after becoming attached, then the chance of getting Lyme disease is very low.

To remove an attached tick:

  • Use tweezers to grab the tick as close to your skin as possible.
  • Pull the tick straight out, using a firm, steady motion; do not jerk the tick.
  • Do not twist, smother, or burn an attached tick; these are not effective methods for tick removal.
  • Do not crush an attached tick.
  • If fingers must be used, protect your fingers with a tissue or plastic bag, grasp the tick as close to the skin as possible, and pull straight out.
  • Wash your hands and the bite site with soap and water after the tick is removed. Apply an antiseptic to the bite site.
  • A localized reaction or infection can occur where the tick was attached. If redness or pain develops at the tick bite site, consult your physician.

How Can I Obtain Additional Information?

More information is available from:
Centers for Disease Control,

California Department of Public Health

Orange County Health Department

Orange County Health Care Agency Animal Care Services