Ticks carry bacteria that can cause human disease. Ehrlichiosis, Rocky Mountain spotted fever, and Lyme disease are infectious
diseases transmitted by tick bites. The Lone Star tick carries Ehrlichia chaffeensis (named to honor bacteriologist Paul Ehrlich),
the bacteria that causes human monocytic ehrlichiosis.
Another type of tick, the deer tick, carries the bacteria responsible for
another type of ehrlichiosis, called human granulocytic
ehrlichiosis. Deer ticks also carry the organism that causes Lyme disease.
The November 10, 2004, issue of JAMA includes an
article about ehrlichiosis.
Nausea or vomiting
Malaise (feeling ill)
Although redness of the skin is common in ehrlichiosis, there is no
distinctive rash. In contrast, Lyme disease usually begins with a spreading
rash, called erythema migrans. If not treated, ehrlichiosis
can progress to a severe illness.
The symptoms of ehrlichiosis are similar to those of viral illnesses
and other bacterial infections. In addition to a careful medical history and
physical examination, testing for ehrlichiosis may include blood counts (looking
for a low white blood cell and low platelet count), and liver enzyme blood
tests. Special staining of a blood smear can show the actual Ehrlichia organisms. More sophisticated laboratory testing may be done
to confirm the diagnosis.
Antibiotic treatment, usually with doxycycline, is effective for ehrlichiosis.
If recognized and treated early, the infection responds quickly to doxycycline
therapy. Supportive care may be needed in advanced cases, including hospitalization
and possibly intensive care. Pregnant women should not take doxycycline, which
is a member of the tetracycline family of antibiotics. Other types of antibiotics
may be used to treat pregnant women or individuals allergic to tetracycline.
All tick-borne diseases can be prevented using the same measures. Wearing
long pants and long sleeves, tucking pants into boots or socks, wearing light-colored
clothing, and using hats and gloves are all ways to protect yourself against
ticks. If you are outdoors in a known tick-infested area, check yourself for
ticks and remove them as soon as you see them. Because there is a delay between
the time of a tick bite and transmission of the disease-causing bacteria from
the tick, removing ticks quickly may help prevent infection. Using an insect
repellent containing DEET (diethyl-meta-toluamide) is an effective way to
repel ticks. It is important to follow the instructions on the label of any
Centers for Disease Control and Prevention 800/232-2522 http://www.cdc.gov
American Lyme Disease Foundation 914/277-6970 http://www.aldf.com
To find this and previous JAMA Patient Pages, go to the Patient Page
link on JAMA's Web site at http://www.jama.com. Many are available in English and Spanish. A Patient Page on Lyme
disease was published in the February 2, 2000, issue.
Sources: Centers for Disease Control and Prevention, American Lyme Disease
Foundation, National Institute of Allergy and Infectious Diseases
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate
in most instances, but they are not a substitute for medical diagnosis. For
specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied
noncommercially by physicians and other health care professionals to share
with patients. Any other print or online reproduction is subject to AMA approval.
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TOPIC: INFECTIOUS DISEASES
Torpy JM, Glass TJ, Glass RM. Ehrlichiosis. JAMA. 2004;292(18):2302. doi:10.1001/jama.292.18.2302