Ticks & Lyme Disease
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) |
Important Links
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- 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
- 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
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.
Lyme disease can be treated with antibiotics. |
Symptoms can vary from person to person but can include:
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Other symptoms that may develop if the disease is not diagnosed and treated:
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Rocky Mountain Spotted Fever
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.
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Symptoms of RMSF include:
For more information about ticks, Lyme disease, Rocky Mountain Spotted Fever, and ehrlichiosis visit the following websites: |
Crawford County Soon to be Listed as a Suspected County for Presence of Deer Ticks
Curt Colwell, Ph.D. with IDPH has received 3 blacklegged / “deer” ticks (Ixodes scapularis) from Crawford County over the years. This indicates that the species may be present in the county. For it to be “established” by CDC criteria, we would have to have seen 6 specimens or 2 life stages.
However, because the deer tick / blacklegged tick is established in Clark and Lawrence counties and in nearby Indiana it is likely that the species will be transported by deer into Crawford County. Blacklegged/ "deer ticks" are the main vector for transmitting lyme disease.
See the map of the “known” distribution of Ixodes scapularis here
For more information concerning the deer / blacklegged tick see the Department’s fact sheet “Common Ticks” here
For more information about lyme disease and how to avoid tick bites, please visit the following websites from the
Centers for Disease Control
http://www.cdc.gov/lyme/Transmission/
http://www.cdc.gov/lyme/signs_symptoms/
http://www.cdc.gov/Features/LymeDisease/
http://www.cdc.gov/niosh/topics/lyme/
However, because the deer tick / blacklegged tick is established in Clark and Lawrence counties and in nearby Indiana it is likely that the species will be transported by deer into Crawford County. Blacklegged/ "deer ticks" are the main vector for transmitting lyme disease.
See the map of the “known” distribution of Ixodes scapularis here
For more information concerning the deer / blacklegged tick see the Department’s fact sheet “Common Ticks” here
For more information about lyme disease and how to avoid tick bites, please visit the following websites from the
Centers for Disease Control
http://www.cdc.gov/lyme/Transmission/
http://www.cdc.gov/lyme/signs_symptoms/
http://www.cdc.gov/Features/LymeDisease/
http://www.cdc.gov/niosh/topics/lyme/
