Treatment of Suspected Leptospirosis
Start antibiotics immediately upon clinical suspicion without waiting for laboratory confirmation, as early treatment is critical for preventing life-threatening complications. 1, 2
Immediate Clinical Assessment
When evaluating a patient with suspected leptospirosis, look for these specific diagnostic features:
- Characteristic triad: Sudden onset fever with severe myalgias, conjunctival suffusion (a distinctive finding that should immediately raise suspicion), and exposure history to contaminated water or flooding 1, 2
- Exposure history: Recent contact with flood water, occupational animal exposure, recreational water sports, or travel to endemic tropical/subtropical regions 1, 2, 3
- Biphasic illness pattern: Initial bacteremic phase lasting 4-7 days with flu-like symptoms, potentially followed by an immune phase with fever, severe muscle pain, and organ failure 1, 4
Antibiotic Treatment Algorithm
For Mild-to-Moderate Disease (Early Phase)
- Doxycycline or penicillin or tetracycline started during the bacteremic phase 1, 2, 5
- Treatment must begin before day 4 of illness for optimal effectiveness 6
For Severe Disease (Weil's Disease)
- Immediate antibiotic therapy with penicillins, macrolides, or third-generation cephalosporins 7, 3
- Plus intensive supportive care including potential renal replacement therapy and liver support 1, 2
- Severe disease features include: jaundice with hepatorenal syndrome, hemorrhagic manifestations, and multi-organ dysfunction 2, 3
Critical Diagnostic Limitations
Laboratory testing should not delay treatment:
- Serology (IgM ELISA, MAT) only becomes positive 6-10 days after symptom onset—too late for early treatment decisions 1, 2
- Blood cultures are only useful if obtained within the first 5 days before antibiotics 1
- Initial laboratory findings are non-specific: proteinuria, hematuria, leukocytosis, high bilirubin with mild transaminase elevation 2
Prophylaxis Considerations (Post-Exposure)
When to Consider Prophylaxis
- Reserve for high-risk settings where attack rates exceed 10 cases per 100 person-years 1, 8
- Mass outbreak situations with documented high attack rates following severe flooding 1, 8
- Doxycycline 200 mg single dose provides 76.8% protective efficacy against infection 8
Prophylaxis Contraindications
- Never use doxycycline in children under 8 years—causes permanent tooth discoloration and enamel hypoplasia with no established alternative 1, 8
Critical Pitfalls to Avoid
- Delaying treatment while awaiting laboratory confirmation leads to preventable deaths 1, 2
- Assuming mild symptoms will remain mild—even with treatment, patients can rapidly progress to critical illness 1
- Underestimating severity based on modest transaminase elevations—bilirubin elevation with hepatorenal syndrome indicates severe disease 2
- Ignoring exposure history—occupational or recreational water contact in endemic areas is essential for clinical suspicion 1
Mandatory Public Health Notification
Leptospirosis is a notifiable disease requiring statutory notification to local health protection units for outbreak investigation and prevention 9