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 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.
Larvae and nymphs are about the size of a "." while adult ticks vary between a small "o" and a large "O".
|Black-Legged Tick (male)
|Black-Legged Tick (male)
|Black-Legged Tick (female)
|Black-Legged Tick (female)
|Black-Legged Tick "Questing"
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.
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
What Are The Symptoms?
Many body systems can be affected by Lyme disease. Symptoms vary from person to person and can come and go. Symptoms are generally classified into early or late. Early symptoms occur days to weeks after a person becomes infected. Early symptoms include:
- Flu-like symptoms such as muscle aches, joint pain, fatigue, headache, stiff neck, chills,
fever, or swollen lymph nodes
- Paralyzed muscles of the face
- Palpitations (common) or disturbances of heart rhythm (rare)
- An expanding rash called erythema migrans, or EM. The EM appears 1-30 days after the bite of an infected tick, expands over a one to two week period, and then disappears. More EMs, not necessarily at the site of the tick bite, can show up later. The EM is usually painless. The EM varies in shape and appearance. On dark skin the EM can look more like a bruise. The EM is not present in some people, or it may occur on a part of the body that is difficult to see
Painful redness that occurs less than 24 hours after a tick bite and does not expand is more likely to be a local allergic reaction to the tick's saliva. These symptoms can disappear without treatment but the infection may still be present. If early Lyme disease symptoms are not recognized and treated adequately, the disease may progress and be more difficult to treat.
Late symptoms occur weeks, months, or years after becoming infected. Late symptoms may be the first sign of Lyme disease in some people. Late symptoms include:
- Numbness, tingling, or burning feelings in arms and legs. Muscles of the face, arms, or legs may twitch or become weak or paralyzed. Sharp pain in the arms, legs, neck, and back, may occur. Increased sensitivity to light may be present
- Swelling and pain of one or a few joints, especially the knees. Joint swelling sometimes moves from one joint to another, and may come and go
- Difficulties with memory, concentration, learning, or speech in both children and adults
- Some Lyme disease patients also experience mood swings, depression, or abnormal thought processes
Diagnosis and Treatment
People with symptoms of Lyme disease should see their doctor as early as possible. Some tick-borne diseases in California (e.g., anaplasmosis, ehrlichiosis and babesiosis), as well as other diseases, can produce symptoms similar to Lyme disease. Thus, Lyme disease can be difficult to diagnose.
A physician diagnoses Lyme disease based on symptoms. Additional information useful to a physician in making a diagnosis of Lyme disease include:
- Patient had a tick bite or was in an area where ticks occur. Because ticks are small, some people do not notice that they have been bitten
- Blood tests, but these need to be interpreted carefully
Prompt treatment with antibiotics during early Lyme disease can cure the infection and prevent complications of late Lyme disease. If treatment is delayed, treatment can be difficult and recovery may take longer.
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
Orange County Vector Control District
13001 Garden Grove Blvd.
Garden Grove, CA 92843