What is the treatment for Leptospirosis?

Treatment of Leptospirosis

For mild to moderate leptospirosis, start doxycycline or penicillin as soon as possible; for severe leptospirosis (Weil's disease), initiate intravenous penicillin or doxycycline within 1 hour of recognition without waiting for laboratory confirmation. 1

Clinical Classification and Recognition

Leptospirosis presents in two distinct forms that guide treatment decisions:

• Mild to moderate form: Flu-like symptoms including high fever (≥39°C), diffuse myalgias (especially calves), headache, and conjunctival suffusion—this is the most common presentation 1
• Severe form (Weil's disease): Characterized by hemorrhage, jaundice, and hepato-renal failure, occurring in approximately 5-10% of cases 1

Key clinical indicators of progression to severe disease include jaundice and cardiac involvement (clinically or on ECG), which should trigger immediate escalation of care. 2

Treatment Approach by Severity

Mild to Moderate Leptospirosis

Start antibiotics as soon as possible, ideally before day 4 of symptoms, as delayed treatment reduces effectiveness. 1

Antibiotic options:

• Doxycycline (preferred oral agent) 1, 3
• Penicillin (alternative oral or parenteral agent) 1, 3

Duration: Standard 7-day course, extending to 10 days if clinical response is slow 1

Hospitalization criteria: Admit patients with moderate leptospirosis showing systemic signs of infection, even without meeting criteria for severe disease 1

Severe Leptospirosis (Weil's Disease)

Critical timing: Initiate antibiotics within the first hour of recognizing severe sepsis or septic shock—each hour of delay increases mortality 1

Antibiotic regimen:

• Intravenous penicillin or tetracyclines (doxycycline) 1
• Standard 7-day course, extending to 10 days with slow clinical response 1
• Reassess antimicrobial regimen daily for potential de-escalation 1

Do not wait for laboratory confirmation before starting treatment in suspected severe cases. 1

Supportive Care for Severe Disease

Fluid resuscitation priorities:

• Target systolic blood pressure >90 mmHg in adults with adequate tissue perfusion 1
• Monitor continuously for crepitations indicating fluid overload or cardiac dysfunction 1
• Never leave septic patients unattended; frequent clinical examinations are mandatory 1

ICU admission criteria: Persistent or worsening tissue hypoperfusion despite initial fluid resuscitation 1

Source control: Consider within 12 hours if applicable 1

Diagnostic Considerations During Treatment

Obtain blood cultures before antibiotics if this causes no significant delay (<45 minutes), ideally within the first 5 days of illness. 1

Laboratory findings supporting diagnosis:

• IgM titers >1:320 are highly suggestive 1
• IgM titers 1:80-1:160 suggest early infection 1
• Proteinuria, hematuria, leukocytosis, elevated bilirubin with mild transaminase elevation 1
• Thrombocytopenia (platelets <140 G/L) occurs in 65.5% of cases 2

Critical Pitfalls to Avoid

Do not discontinue antibiotics early—complete the full 7-10 day course even with clinical improvement 1

Do not delay treatment waiting for serologic confirmation—clinical diagnosis based on epidemiologic exposure and compatible symptoms should trigger immediate antibiotic initiation 1, 4

Do not misdiagnose as viral hepatitis—consider leptospirosis in any patient with fever and jaundice, especially with exposure history 1

Treatment initiated after 4 days of symptoms may be significantly less effective, emphasizing the critical importance of early recognition and prompt antibiotic administration 1

Antimicrobial Sensitivity

Leptospires are sensitive to multiple antimicrobial classes including penicillins, cephalosporins, aminoglycosides, tetracyclines, and macrolides 5. Short-term streptomycin treatment can eradicate leptospires, while penicillins, cephalosporins, tetracyclines, and macrolides may require longer therapy with larger doses from early disease until antibody appearance 5.