Human ehrlichiosis is an infection caused by two bacterial species, Ehrlichia chaffeensis and Ehrlichia ewingii. Ehrlichiosis is contracted from the bite of an infected tick. Typical symptoms include fever and chills, muscle and joint aches, cough, headache, nausea, vomiting and diarrhea. A rash affecting primarily the trunk and arms may also be present. The Centers for Disease Control and Prevention (CDC) recommends antibiotic therapy for symptomatic ehrlichiosis.
Doxycycline
The CDC states that the treatment of choice for ehrlichiosis is the antibiotic doxycycline. When doxycycline is administered within the first four to five days of the illness, the fever typically subsides within 24 to 48 hours of treatment. This therapeutic response is so predictable that if the fever fails to break within 48 hours, the diagnosis of ehrlichiosis may be called into question. A typical course of antibiotic therapy is seven to 14 days, depending on the severity of the illness and other factors.
Tetracycline
Tetracycline is in the same class of antibiotics as doxycycline and may be used as an alternative to doxycycline for the treatment of ehrlichiosis.
Chloramphenicol
Chloramphenicol is an alternative antibiotic therapy for ehrlichiosis, if doxycycline cannot be given due to allergy, pregnancy or another contraindication. Chloramphenicol is often the preferred treatment for pregnant women, especially in the first two trimesters of pregnancy. However, chloramphenicol may cause serious side effects; careful monitoring is important for patients receiving this medication. Overall, chloramphenicol is not considered as effective for ehrlichiosis as doxycycline.
Rifampin
The antibiotic rifampin may be used to treat ehrlichiosis in pregnant women or people who are allergic to tetracyclines, though its use for this condition has not been extensively studied.
Hospitalization
Ehrlichiosis can be a serious illness. The CDC reports that roughly 50% of ehrlichiosis patients require hospitalization. People with a compromised immune system often have severe disease with this infection. Advanced age and delayed diagnosis may also lead to a severe clinical course.
References
- Merck Manual: Ehrlichiosis
- Ohio State University: Human ehrlichiosis
- Centers for Disease Control and Prevention: MMWR, Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis
- Centers for Disease Control and Prevention: Ehrlichiosis questions and answers
- Journal of Vector Borne Diseases: Tick-borne ehrlichiosis infection in human beings
