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
- For 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
- For children under 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 complications, long-term sequelae, or death 1, 2
Alternative Treatment Options
- Azithromycin: Single 500-mg dose has shown equivalent efficacy to doxycycline in mild scrub typhus cases 3
- Azithromycin is the preferred treatment for pregnant women and has been associated with favorable pregnancy outcomes 4
- Chloramphenicol: Alternative when doxycycline cannot be used 4
- Rifampicin: Effective alternative, particularly in areas where doxycycline resistance has been reported 5, 6
- Other alternatives include tetracycline, ciprofloxacin, and roxithromycin 4
Treatment Response and Duration
- Patients typically respond to appropriate antibiotics within 24-48 hours; lack of response within this timeframe should prompt consideration of alternative diagnoses 1
- 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
- Early initiation of appropriate antibiotics significantly reduces complications and mortality 2
- In a study comparing rifampicin (600 mg once daily for 5 days) with doxycycline (100 mg twice daily for 5 days), both treatments showed equivalent efficacy and safety profiles 5
- The historical concern about dental staining in children under 8 years should not prevent the use of doxycycline for short courses of treatment 1
Complications and Prognosis
- If untreated, scrub typhus can lead to serious complications involving multiple organs 4
- Mortality rates of up to 4% have been reported 1
- Patients who receive early treatment with appropriate antibiotics have significantly better outcomes 2
- In one study, none of the patients who received early anti-scrub typhus antibiotics (doxycycline or azithromycin) died, while those who presented late (average 9.2 days of illness) with severe complications had higher mortality 2
Key Points for Treatment Success
- Initiate treatment based on clinical suspicion without waiting for laboratory confirmation 1, 2
- Monitor for clinical response within 24-48 hours of starting treatment 1
- Complete the full course of antibiotics even after symptoms resolve 1
- Consider alternative diagnoses if no improvement occurs within 48 hours 1