Tick Bite Prophylaxis

The Infectious Disease Society of America (IDSA) does not generally recommend antimicrobial prophylaxis for prevention of Lyme disease after a recognized tick bite. However, in areas that are highly endemic for Lyme disease, a single dose of doxycycline may be offered to adult patients (200 mg) who are not pregnant and to children older than 8 years of age (4 mg/kg up to a maximum dose of 200 mg) when all of the following circumstances exist:

1. Doxycycline is not contraindicated.
2. The attached tick can be identified as an adult or nymphal I. scapularis tick.
3. The estimated time of attachment is ≥36 h based on the degree of engorgement of the tick with blood or likely time of exposure to the tick.
4. Prophylaxis can be started within 72 h of tick removal.
5. Lyme disease is common in the county or state where the patient lives or has recently traveled, (i.e., CT, DE, MA, MD, ME, MN, NH, NJ, NY, PA, RI, VA, VT, WI).

Antibiotic treatment following a tick bite is not recommended as a means to prevent anaplasmosis, babesiosis, ehrlichiosis, or Rocky Mountain spotted fever. There is no evidence this practice is effective, and it may simply delay onset of disease. Instead, persons who experience a tick bite should be alert for symptoms suggestive of tickborne illness and consult a physician if fever, rash, or other symptoms of concern develop.

Tularemia prophylaxis is recommended only in cases of laboratory exposure to infectious materials:

• Doxycycline (100 mg orally BID X 14 days) is generally recommended for prophylaxis in adults.
• Ciprofloxacin (500 mg orally BID) is not FDA-approved for prophylaxis of tularemia but has demonstrated efficacy in various studies, and may be an alternative for patients unable to take doxycycline.