Ticks & Lyme Disease

Image source: Centers for Disease Control & Prevention

 

Ticks are a common pest that are encountered in the outdoors. Ticks are very efficient carriers of disease because once attached, they may go unnoticed for a period of time while they feed on their host. Ticks are commonly found on grass, weeds, and shrubs and will wait until a host moves by, when they will let go and climb onto the host. Ticks become more active when ground temperatures reach 40 degrees F, with peak activity occurring in the late spring and early summer months. There have been reports of ticks attaching themselves to a host in winter months.

Ticks are found in two groups: "hard" ticks and "soft" ticks. As their name implies, hard ticks have a hard shield and are shaped like a flat seed when unfed. Soft ticks lack the hard shield and are shaped like a large raisin. The soft ticks generally feed on birds and bats.

Of the at least 15 species of ticks found in Illinois, only a few are likely to be encountered by people. Those species include: American dog tick, lone star tick, blacklegged (deer) tick, brown dog tick, and winter tick. A printable tick identification card can be found by clicking the following link. Tick identification card (PDF format)

• American dog tick (wood tick) (Dermacentor variabilis) - one of the most frequently encountered ticks; feed on humans and mammals such as raccoons and dogs; reddish-brown color and ~1/4 inch long when unfed; can transmit Rocky Mountain spotted fever, tularemia, and possibly ehrlichiosis

• Lone Star tick (Amblyomma americanum) - will feed on various mammals, including humans; brown colored and ~1/8 inch long, female has a white spot in middle of back; can transmit Rocky Mountain spotted fever and may transmit tularemia and ehrlichiosis

• Blacklegged (deer) tick (Ixodes scapularis) - feeds on a variety of hosts including people; reddish-brown color and ~1/8 inch long, found in wooded areas near trails, can transmit Lyme disease and ehrlichiosis

From left to right: deer tick female, male, nymph, larva

Image source: Centers for Disease Control & Prevention

• Brown dog tick (kennel tick) (Rhipicephalus sanguineus) - feeds primarily on dogs; generally found in kennels or homes with dogs; reddish-brown color and ~1/8 inch long, female may grow to 1/2 inch long after feeding; not an important carrier of human disease

• Winter tick - feeds on large mammals; attaches to host as larva and remains there throughout life; may be found on deer carcasses by hunters; not known to transmit disease to humans

Preventing Tick Bites

• Wear protective clothing: long sleeves, long pants, hats, tuck pant legs into your socks
• Apply insect repellents containing DEET to clothing; another repellent, permethrin, can be applied to clothing, but should not be applied to skin
• Walk in areas where weeds will not brush against you
• Check yourself and others for ticks frequently
• Promptly remove ticks that are crawling on clothes with something like tape that the tick will stick to. Do not touch the tick with bare hands.
• If a tick has become embedded, use tweezers to grasp it as close to the skin as possible and then gently pull it straight out. Discard tick in a container of alcohol or soapy water, sticking them to tape, or by flushing down the toilet.
• Wash the bitten area thoroughly with soap and water and use an antiseptic on the area
• Keep your grass mowed and weeds cut to help prevent ticks from inhabiting your property

If you would like a tick identified, place it in a leak-proof container with rubbing alcohol with the date and location the tick where the tick was encountered and contact your local health department.

After a tick bite, if you begin to experience a "bull's-eye" like rash, other rash, or unexplainable illness accompanied by fever, consult with your doctor.

 

Lyme Disease

Lyme disease is a bacterial disease caused by the bacterium Borrelia burgdorferi. The disease is transmitted by an infected blacklegged (deer) tick (Ixodes scapularis) that bites its host. It's important to note that not all deer ticks carry the bacterium that causes Lyme disease.

Symptoms can vary from person to person but can include:

• "bull's-eye" like rash that could begin up to one month after the bite
• fatigue
• chills & fever
• headache
• swollen lymph nodes
• joint & muscle pain

Other symptoms that may develop if the disease is not diagnosed and treated:

• fever
• severe headache
• stiff neck
• heart irregularities
• temporary paralysis of facial muscles
• pain with numbness or weakness in arms & legs
• loss of concentration or memory problems
• Lyme arthritis

Lyme disease can be treated with antibiotics.

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever is another disease spread by infected ticks, either the American dog tick or the lone star tick. The bacteria that causes RMSF is Rickettsia rickettsii. Not all ticks will carry the infection. In recent years, the number of probable cases has increased in Illinois.

Symptoms of RMSF include:

• moderate to high fever that could appear suddenly and last for up to 3 weeks
• fatigue
• muscle pains
• headache
• chills
• rash on extremeties that may spread to other parts of body

Rocky Mountain Spotted Fever can be treated with antibiotics, and with early diagnosis, treatment is more successful.

 

For more information about ticks, Lyme disease, Rocky Mountain Spotted Fever, and ehrlichiosis visit the following websites:

IDPH Tick webpage

IDPH Lyme disease Healthbeat

CDC Lyme disease webpage

IDPH Rocky Mountain spotted fever Healthbeat

IDPH Ehrlichiosis Healthbeat

IDPH Tularemia Healthbeat

 

Updated 1/12/10