What is the recommended treatment for scrub typhus?

Treatment of Scrub Typhus

Doxycycline is the drug of choice for treatment of scrub typhus in patients of all ages, including children under 8 years, and should be initiated immediately when scrub typhus is suspected. 1

First-Line Treatment Regimens

• Adults: Doxycycline 100 mg twice daily (orally or intravenously) for at least 3 days after fever subsides and until evidence of clinical improvement is noted; minimum treatment course of 5-7 days 1
• Children <45 kg: Doxycycline 2.2 mg/kg body weight twice daily (orally or intravenously) 1
• Treatment should never be delayed while awaiting laboratory confirmation, as delay can lead to severe disease, long-term sequelae, or death 1
• Patients typically respond to appropriate antibiotics within 24-48 hours; lack of response within this timeframe should prompt consideration of alternative diagnoses 1

Alternative Treatment Options

• Azithromycin: A single 500-mg dose has been shown to be as effective as a 1-week course of doxycycline for mild scrub typhus 2

  • Particularly recommended for pregnant women and young children 3, 4
  • Has demonstrated effectiveness against doxycycline-resistant strains in vitro 5

• Rifampin: 600 mg once daily for 5 days has shown equivalent treatment effects to doxycycline 6

  • Particularly useful in areas where doxycycline resistance has been documented 4

• Other alternatives with varying levels of evidence:

  • Chloramphenicol 3
  • Tetracycline 3
  • Ciprofloxacin 3
  • Roxithromycin 3

Special Populations

• Pregnant women: Azithromycin is the preferred treatment, with documented successful outcomes without relapse 3, 4
• Children: While historically there were concerns about dental staining with doxycycline in children under 8 years, short courses are now considered safe and appropriate for treating scrub typhus 1

Treatment Response and Duration

• Most patients show clinical improvement within 24-48 hours of starting appropriate antibiotic therapy 1, 2
• Continue treatment for at least 3 days after fever subsides 1
• Minimum treatment course is typically 5-7 days 1
• Severe or complicated disease may require longer treatment courses 1

Clinical Considerations

• Scrub typhus can lead to serious complications if untreated, including disseminated vasculitis, vascular leakage, and end-organ injury 3
• Laboratory findings often include leukopenia, thrombocytopenia, and deranged hepatic and renal function 3
• The characteristic eschar (a flat black crust at the site of the mite bite) may be present and aids in diagnosis 3
• Doxycycline is indicated for treatment of rickettsial infections including tick fevers, which are similar to scrub typhus 7

Antibiotic Resistance Considerations

• Doxycycline-resistant strains have been reported, particularly in northern Thailand 4
• In areas with known resistance, rifampin or azithromycin should be considered as first-line therapy 6, 4, 5