What is the recommended treatment for leptospirosis in children?

Treatment of Leptospirosis in Children

For children with suspected or confirmed leptospirosis, initiate antibiotic therapy immediately upon clinical suspicion with either penicillin or tetracycline antibiotics (doxycycline for children >7 years), as early treatment during the bacteremic phase reduces morbidity even though severe disease may be immunologically mediated. 1

Antibiotic Selection by Disease Severity

Mild to Moderate Disease (Outpatient)

• Oral doxycycline is preferred for children >7 years old at 2-4 mg/kg/day divided into 2 doses 2
• Oral amoxicillin (90 mg/kg/day in 2 doses, maximum 4 g/day) is an acceptable alternative, particularly for younger children where tetracyclines are contraindicated 2
• Oral azithromycin (10 mg/kg on day 1, then 5 mg/kg/day for days 2-5) can be used as a macrolide alternative 3, 4

Severe Disease (Weil's Disease - Hospitalized Patients)

• Intravenous crystalline penicillin G is the drug of choice for severe leptospirosis in children, though specific pediatric dosing is not detailed in the guidelines 2
• Intravenous ceftriaxone (50-100 mg/kg/day every 12-24 hours) or cefotaxime (150 mg/kg/day every 8 hours) are acceptable alternatives for severe disease 1
• Intravenous ampicillin (150-200 mg/kg/day every 6 hours) can be used for hospitalized patients 1

Critical Clinical Considerations

When to Treat

• Do not wait for laboratory confirmation - treatment should begin upon clinical suspicion given the non-specific nature of initial investigations and the time delay for serologic confirmation (6-10 days for earliest positives) 1
• Look for the classic triad: fever, myalgia (especially calf muscles), and conjunctival suffusion following freshwater exposure 1
• Consider leptospirosis in any child with acute febrile illness during monsoon season or after contact with contaminated water (88% of cases) 5, 2

Disease Phases and Treatment Timing

• Leptospirosis follows a biphasic course: initial bacteremic phase (4-7 days) with flu-like symptoms, followed by an immune phase (1-3 days later) with hepatorenal syndrome and hemorrhage 1
• Antibiotics are most effective during the bacteremic phase (first 5 days), though treatment should continue even in late presentation 1, 5
• A systematic review showed no benefit for antibiotics in established severe disease, but most infectious disease specialists continue to recommend them as severe disease is likely immunologically mediated 1

Supportive Care Requirements

• Monitor for renal failure (occurs in 79% of pediatric cases), elevated transaminases (56%), thrombocytopenia (65%), and hemorrhagic manifestations (11.6%) 5
• Pulmonary hemorrhage with respiratory failure is a life-threatening complication requiring intensive care 5
• Antimicrobial therapy has been shown to reduce the extent of renal failure and thrombocytopenia in children 5
• Patients with Weil's disease (jaundice, hepatorenal failure) may require renal or liver support despite appropriate antibiotic therapy 1

Diagnostic Confirmation

• Serologic testing: IgM titer >1:320 is suggestive; 1:80 to 1:160 suggests early infection but may represent cross-reactions 1
• Blood cultures should be obtained within the first 5 days before antibiotics and kept at room temperature for reference laboratory dispatch 1
• Convalescent serology (>10 days after symptom onset) with IgM ELISA and microscopic agglutination test (MAT) confirms diagnosis 1
• Urine is not suitable for leptospira isolation 1

Treatment Duration and Monitoring

• Duration: Long-term therapy with large doses may be required from early disease stage until antibody appearance when using penicillins, cephalosporins, tetracyclines, or macrolides 4
• Streptomycin provides short-term eradication but is less commonly used 4
• Expected improvement: Clinical response should occur within 48-72 hours of appropriate therapy 5
• Mortality in severe pediatric leptospirosis is primarily from respiratory failure, emphasizing the need for aggressive supportive care 5

Common Pitfalls to Avoid

• Do not delay treatment waiting for serologic confirmation, as early antibiotics reduce complications 5, 2
• Do not dismiss the diagnosis in children without jaundice - 30% of pediatric cases are anicteric 5, 2
• Do not overlook epidemiologic clues: contact with flood waters, rodent exposure, or recreational water activities in endemic areas 3, 5, 2
• Do not use tetracyclines in children <7 years old due to dental staining concerns 2