- Doxycycline is the treatment of choice for anaplasmosis, and all other tickborne rickettsial diseases. Presumptive treatment with doxycycline is recommended in patients of all ages, including children <8 years.
- Doxycycline is most effective at preventing severe complications from developing if it is started early in the course of disease.
- When treated with doxycycline, fever generally subsides within 24–48 hours.
- Lack of a clinical response to doxycycline suggests that the patient’s condition might not be due to anaplasmosis, or might be caused by other infections not responsive to doxycycline (see coinfections).
- Resistance to doxycycline or relapses in symptoms after the completion of the recommended course have not been documented.
Recommended Treatment and Dosage for Anaplasmosis
Doxycycline is the first-line treatment for adults and children of all ages:
- Adults: 100 mg every 12 hours
- Children under 45 kg (100 lbs): 2.2 mg/kg body weight given twice a day
Patients with suspected anaplasmosis should be treated with doxycycline for 10–14 days to provide appropriate length of therapy for possible concurrent Lyme disease infection.
Treating Children and Pregnant Women
- The use of doxycycline to treat suspected rickettsial disease in children is standard practice recommended by both CDC and the American Academy of Pediatrics Committee on Infectious Diseases.
- A recent study found that short courses of doxycycline (5–10 days) did not result in staining of permanent teeth or enamel hypoplasia. Use doxycycline as the first-line treatment for suspected anaplasmosis in patients of all ages.
- Use of antibiotics other than doxycycline increases the risk of severe illness and patient death.
- In cases of life-threatening allergies to doxycycline, severe doxycycline intolerance, and in some pregnant patients for whom the clinical course of anaplasmosis appears mild, physicians should consider alternate antibiotics.
- Rifampin has been used successfully in several pregnant women with anaplasmosis, and studies suggest that this drug appears effective against A. phagocytophilum.
- Small numbers of children <8 years of age have also been treated successfully for anaplasmosis with rifampin following a 7–10 day course.
- However, rifampin is not effective in treating RMSF, a disease that might be confused with anaplasmosis, nor is it an effective treatment for potential coinfection with Lyme disease.
- Healthcare providers should be cautious when exploring treatments other than doxycycline, which is highly effective in treating multiple tickborne diseases including anaplasmosis, ehrlichiosis, Lyme disease, and RMSF.
Antibiotics as Prophylaxis
- Post-tick bite antibiotic prophylaxis is not recommended to prevent anaplasmosis.
- People who have been bitten by a tick should watch for signs and symptoms. They should see their healthcare provider if fever, rash, or other symptoms develop within two weeks of tick bite.
- Asymptomatic treatment for tick bites is not currently recommended.
For more in-depth information about the recommended treatment for anaplasmosis, see: Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States: A Practical Guide for Health Care and Public Health Professionals (2016) Cdc-pdf[PDF – 48 pages]