Ehrlichiosis

Ehrlichiosis is the general name used to describe several bacterial diseases that affect animals and humans. These diseases are caused by the organisms in the genus Ehrlichia. Worldwide, there are currently four ehrlichial species that are known to cause disease in humans.

In the United State, there were about 1200 reported cases of ehrlichiosis to CDC during 1986 to 1997.

Symptoms

The symptoms of ehrlichiosis may resemble symptoms of various other infectious and non-infectious diseases. These clinical features generally include fever, headache, fatigue, and muscle aches. Other signs and symptoms may include nausea, vomiting, diarrhea, cough, joint pains, confusion, and occasionally rash. Symptoms typically appear after an incubation period of 5-10 days following the tick bite. It is possible that many individuals who become infected with ehrlichiae do not become ill or they develop only very mild symptoms.

Transmission

In the United States, ehrlichiae are transmitted by the bite of an infected tick. The lone star tick (Amblyomma americanum), the blacklegged tick (Ixodes scapularis), and the western blacklegged tick (Ixodes pacificus) are known vectors of ehrlichiosis in the United States. Ixodes ricinus is the primary vector in Europe.

Treatment

Ehrlichiosis is treated with a tetracycline antibiotic, usually doxycycline.

References:

Centers for Disease Control and Prevention, USA.