What is the recommended treatment for a patient suspected of having leptospirosis?

Leptospirosis Management

Immediate Treatment Approach

Start antibiotics immediately upon clinical suspicion of leptospirosis without waiting for laboratory confirmation, as each hour of delay increases mortality. 1

The treatment strategy depends on disease severity:

Mild to Moderate Disease

Doxycycline 100 mg orally twice daily for 7 days is the treatment of choice for mild to moderate leptospirosis. 1, 2

• This regimen reduces illness duration by approximately 2 days and favorably affects fever, malaise, headache, and myalgias 2
• Alternative oral antibiotics include amoxicillin if doxycycline is unavailable 1
• Treatment should be initiated as soon as possible, ideally within the first 4 days of symptoms, as later initiation may be less effective 1

Severe Disease (Weil's Disease)

For severe leptospirosis with jaundice, hemorrhage, renal failure, or respiratory complications, use ceftriaxone 2g IV daily for 7 days. 1, 3

• Ceftriaxone demonstrated superior convenience and adverse effect profile compared to penicillin regimens, with 21 of 22 patients recovering in one study 3
• Penicillin G 1.5 million units IV every 6 hours is an alternative for severe disease 1
• The standard course is 7 days but may be extended to 10 days in patients with slow clinical response 1

Critical Supportive Care Measures

Aggressive IV fluid resuscitation is essential for severe disease, with isotonic crystalloid or colloid solution up to 60 mL/kg administered as three boluses of 20 mL/kg, reassessing after each bolus. 1

• Monitor closely for development of crepitations indicating fluid overload or impaired cardiac function during resuscitation 1
• Target systolic blood pressure >90 mmHg in adults with normal heart rate 1
• ICU admission is indicated for patients with persistent tissue hypoperfusion despite initial fluid resuscitation, repeated fluid bolus requirements, or signs of circulatory failure 1
• Methylprednisolone 0.5-1.0 mg/kg IV daily for 1-2 weeks may be used for respiratory complications 1

Diagnostic Workup

While treatment should not be delayed, obtain the following for diagnostic confirmation:

• Blood cultures (ideally within first 5 days before antibiotics if this causes no significant delay <45 minutes) 1
• Complete blood count, comprehensive metabolic panel, urinalysis 1
• IgM ELISA serology (titer >1:320 is diagnostic, though often negative in first week) 1
• Convalescent serology with microscopic agglutination test (MAT) repeated >10 days after symptom onset 1

Key Clinical Features to Assess

Exposure history within the past 2-20 days is critical, including contact with flood water, contaminated fresh water, or animals (rats, dogs, cattle). 1, 4

Physical examination findings that strongly suggest leptospirosis:

• Conjunctival suffusion (highly suggestive) 1
• Jaundice (indicates severe disease) 1
• Signs of hemorrhage 1
• Hepatomegaly 1
• Respiratory distress or hypoxemia 1

The characteristic biphasic course includes an initial bacteremic phase (4-7 days) with high fever (≥39°C), severe myalgias especially in calves, and headache 1, 5

Special Populations

In children <8 years, avoid doxycycline due to risk of permanent tooth discoloration; use penicillin or ceftriaxone instead. 1

In pregnant women, avoid tetracyclines and use penicillin or ceftriaxone. 1

Common Pitfalls to Avoid

• Do not wait for serological confirmation before starting antibiotics, as serology is often negative in the first week and delay increases mortality 1
• Do not mistake leptospirosis for viral hepatitis in patients presenting with fever and jaundice 1
• Do not discontinue antibiotics early despite clinical improvement; complete the full 7-day course 1
• Do not use urine for culture, as it is not suitable for leptospira isolation 1
• Expect clinical effect within 3 days of antibiotic initiation; if no improvement, reassess and consider complications 1

Follow-up

• Seriously ill patients should be followed up 2 days after initial visit to assess treatment response 1
• Patients should return if symptoms persist longer than 3 weeks 1

Prophylaxis Consideration

For high-risk post-flood exposure settings, doxycycline 200 mg single dose orally provides 76.8% protection, though this should be reserved for high-risk situations 1