What are the Centers for Disease Control and Prevention (CDC) guidelines for treating Leptospirosis?

Leptospirosis Treatment Guidelines

Treatment of Severe Leptospirosis

For severe leptospirosis, initiate intravenous antibiotics immediately upon recognition without waiting for laboratory confirmation, as early treatment within the first 4 days of symptoms is critical for reducing mortality. 1, 2

First-Line Antibiotic Regimens

Penicillin or cephalosporins (cefotaxime/ceftriaxone) are the preferred agents for severe disease:

• Penicillin G: 6 million units/day IV (1 million units every 4 hours) for 7 days 2
• Ceftriaxone or cefotaxime: Standard dosing for 7 days (may be preferred due to broader coverage and ease of administration) 3
• Doxycycline: 100 mg IV twice daily for 7 days is an acceptable alternative 4, 3

Critical Timing Considerations

• Antibiotics must be started within the first hour of recognizing septic shock or severe sepsis 1
• Treatment initiated after 4 days of symptoms may be significantly less effective, with one randomized trial showing no benefit and potentially higher mortality when penicillin was started late 2
• Extend treatment to 10 days if clinical response is slow 1

Supportive Care Requirements

Fluid resuscitation is essential:

• Target systolic blood pressure >90 mmHg in adults with adequate tissue perfusion 1
• Monitor closely for crepitations indicating fluid overload during resuscitation 1
• Patients with persistent hypoperfusion despite initial resuscitation require ICU admission 1

Treatment of Mild to Moderate Leptospirosis

For mild to moderate disease, oral antibiotics should be started as soon as possible:

• Doxycycline: 100 mg orally twice daily for 7 days 1, 3
• Penicillin: Oral formulations for 7 days 1
• Azithromycin: Shows promise for less severe disease, though data are limited 3

Prophylaxis After Flood Exposure

Doxycycline prophylaxis should be reserved for high-risk settings with attack rates exceeding 10 cases per 100 person-years:

• Single dose of 200 mg doxycycline orally provides 76.8% protective efficacy against infection and 86.3% against clinical disease 5
• Efficacy is increased for those with laceration wounds 5
• Mass prophylaxis campaigns can be implemented following severe flooding with documented high attack rates 5

Prophylaxis Contraindications

Do not use doxycycline in children under 8 years due to risk of permanent tooth discoloration and enamel hypoplasia 5

Prevention Strategies

Primary prevention is more effective than prophylaxis in most settings:

• Avoid contact with flood water, especially with open cuts or abrasions 5, 6
• Use protective equipment (boots, gloves) during high-risk agricultural or occupational activities 5
• Avoid swimming or wading in water potentially contaminated with animal urine 5, 6
• Implement rodent control measures in endemic areas 5

High-Risk Populations

Agricultural workers in rural areas, particularly those working in flooded rice fields, face the highest risk 6

Diagnostic Confirmation

Do not delay treatment while awaiting diagnostic confirmation in suspected severe cases:

• IgM titers >1:320 are suggestive of leptospirosis 1
• Blood cultures are most useful if obtained within the first 5 days before antibiotics 1
• Convalescent serology (>10 days after symptom onset) can confirm diagnosis retrospectively 1

Common Pitfalls to Avoid

• Never delay antibiotic initiation in severe disease waiting for laboratory confirmation - this increases mortality 1
• Do not discontinue antibiotics early - complete the full 7-day course even with clinical improvement 1
• Do not use doxycycline prophylaxis routinely - reserve for documented high-risk settings only 5
• Avoid misdiagnosing as viral hepatitis in patients presenting with fever and jaundice 1