What is the treatment for leptospirosis?

Treatment of Leptospirosis

Start antibiotics immediately for leptospirosis—penicillin or doxycycline for both mild and severe disease—with treatment initiated as soon as possible without waiting for laboratory confirmation, as early therapy is critical for reducing mortality. 1

Antibiotic Selection and Timing

Mild to Moderate Leptospirosis

• Penicillin or tetracyclines (doxycycline) are effective first-line antibiotics that should be started as soon as the diagnosis is suspected clinically 1
• Hospitalization is recommended even for moderate disease with systemic signs of infection, even without criteria for severe disease 1
• Leptospires are sensitive to multiple antimicrobial agents including penicillin, cephalosporins, aminoglycosides, tetracyclines, and macrolides 2

Severe Leptospirosis (Weil's Disease)

• Antibiotics must be started within the first hour of recognizing severe sepsis or septic shock to minimize mortality, as each hour of delay increases death risk 1
• Treatment should not be delayed while waiting for laboratory confirmation 1
• The standard antibiotic course is 7 days, but may need extension to 10 days in patients with slow clinical response 1
• Blood cultures should be obtained before antibiotics if this causes no significant delay (<45 minutes), ideally within the first 5 days of illness 1

Clinical Context for Treatment Decisions

Disease Classification

• Leptospirosis presents in two forms: mild to moderate (flu-like symptoms) occurring most commonly, and severe form (Weil's disease) characterized by hemorrhage, jaundice, and hepato-renal failure occurring in approximately 5-10% of cases 1
• The septicemic phase lasts 4-7 days and is characterized by high fever (≥39°C), diffuse myalgias especially in the calves, headache, and conjunctival suffusion 1, 3

Treatment Effectiveness Considerations

• Early antibiotic administration is critical—treatment initiated after 4 days of symptoms may be less effective 1
• Even in severe cases, antibiotic therapy is effective when treatment is delayed, though earlier is always better 3
• Reassess the antimicrobial regimen daily for potential de-escalation 1

Supportive Care for Severe Disease

Fluid Resuscitation

• Fluid resuscitation with adequate tissue perfusion as the principal endpoint, targeting systolic blood pressure >90 mmHg in adults 1
• Monitor for development of crepitations indicating fluid overload or impaired cardiac function during resuscitation 1
• Continuous observation and frequent clinical examinations are necessary for septic patients 1

ICU Admission Criteria

• Patients with severe leptospirosis require ICU admission if they have persistent or worsening tissue hypoperfusion despite initial fluid resuscitation 1
• Consider source control measures within 12 hours if applicable 1

Critical Pitfalls to Avoid

• Do not discontinue antibiotics too early—complete the full 7-10 day course even with clinical improvement 1
• Do not misdiagnose as viral hepatitis in patients presenting with fever and jaundice; always consider leptospirosis in the differential diagnosis 1
• Do not wait for serologic confirmation before starting treatment in suspected severe cases, as this increases mortality 1
• Avoid leaving septic patients alone—they require continuous observation 1