How do you treat anaplasmosis?

Treatment of Anaplasmosis

Doxycycline is the first-line treatment for anaplasmosis in patients of all ages, including children under 8 years, and should be initiated promptly when anaplasmosis is suspected. 1

First-Line Treatment

• Doxycycline is the only recommended first-line antimicrobial agent for anaplasmosis treatment 2
• Treatment should be initiated empirically based on clinical suspicion, without waiting for laboratory confirmation 1
• Delayed treatment is associated with increased disease severity and poorer outcomes, particularly in high-risk groups 2

Dosing Recommendations

• Adults: 100 mg twice daily orally or intravenously 2
• Children: 2.2 mg/kg per dose twice daily (not to exceed 100 mg per dose) 2
• Duration: Typically 10-14 days, or at least 3 days after fever subsides 1

Special Populations

Children Under 8 Years

• Doxycycline is the treatment of choice despite historical concerns about dental staining 2
• Short courses of doxycycline (≤14 days) do not cause visible dental staining in children 2
• Withholding doxycycline from young children with suspected anaplasmosis contributes to higher mortality rates 2

Pregnant Women

• Rifampin may be considered as an alternative for pregnant women with mild anaplasmosis 2
• Dosing: 300 mg orally twice daily 2
• However, rifampin should only be used after careful consideration, as it does not treat potential coinfections with Borrelia burgdorferi 2

Patients with Tetracycline Allergy

• Rifampin is the only documented alternative for patients with documented tetracycline allergy 2
• Before using rifampin, clinicians must ensure Rocky Mountain Spotted Fever (RMSF) is ruled out, as rifampin is not effective against RMSF 2

Ineffective Treatments to Avoid

• Chloramphenicol: Not effective for anaplasmosis based on in vitro evidence 2
• Beta-lactams, macrolides, aminoglycosides, and sulfonamides: Not effective against tickborne rickettsial diseases 2
• Fluoroquinolones: Despite in vitro activity against A. phagocytophilum, clinical failures have been reported, and they are not recommended 2
• Sulfonamides: May worsen tickborne rickettsial diseases and should be avoided 2

Monitoring and Response to Treatment

• Patients typically show clinical improvement within 24-48 hours after starting doxycycline 3
• Monitor for resolution of fever, headache, and myalgia 2
• Follow laboratory abnormalities: thrombocytopenia, leukopenia, elevated hepatic transaminases, and anemia 2, 3
• Delayed response to treatment may suggest coinfection with other tickborne pathogens, particularly in endemic areas 2

Complications and Considerations

• Approximately 7% of hospitalized patients require intensive care 2
• Risk factors for severe disease include advanced age, immunosuppression, comorbidities like diabetes, and delayed treatment 2, 3
• Be vigilant for opportunistic viral and fungal infections during anaplasmosis treatment, especially in immunocompromised patients 2, 3
• Consider potential coinfections with Borrelia burgdorferi or Babesia microti in endemic areas 2

Common Pitfalls

• Delaying treatment while waiting for laboratory confirmation increases mortality risk 1
• Misdiagnosing rash in RMSF as a drug reaction when treating with sulfonamides or beta-lactams 2
• Using alternative antibiotics when doxycycline is the clear first-line agent, especially in children under 8 years 2
• Failing to recognize potential coinfections when response to treatment is suboptimal 2