What is Leptospirosis?

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From the Guidelines

Leptospirosis is a bacterial infection that requires prompt antibiotic treatment, with oral doxycycline or intravenous penicillin G being the recommended therapies, as suggested by 1.

Key Considerations

  • The infection is typically contracted through contact with water or soil contaminated with urine from infected animals, particularly rodents, as noted in 1.
  • Leptospirosis can range from mild flu-like illness to severe disease with multi-organ failure (Weil's disease), making early recognition and treatment crucial for preventing serious complications, as described in 1 and 1.
  • Treatment should begin as soon as leptospirosis is suspected, without waiting for laboratory confirmation, as early intervention improves outcomes, as recommended in 1.

Treatment Options

  • For mild cases, oral doxycycline 100mg twice daily for 7 days is the recommended first-line therapy.
  • For severe cases requiring hospitalization, intravenous penicillin G (1.5 million units every 6 hours) or ceftriaxone (1g daily) for 7 days is preferred.

Supportive Care

  • Supportive care including hydration, fever management, and monitoring for complications like kidney failure or respiratory distress is essential.
  • Prevention involves avoiding potentially contaminated water, wearing protective clothing when in high-risk environments, and controlling rodent populations.

Clinical Presentation

  • The clinical presentation of leptospirosis varies from mild flu-like symptoms to a severe illness characterized by haemorrhage, jaundice, and hepatorenal failure (Weil’s disease), as described in 1.
  • Conjunctival suffusion is suggestive of leptospirosis, as noted in 1.

From the Research

Overview of Leptospirosis

  • Leptospirosis is a zoonotic disease that can cause significant morbidity and mortality 2
  • The disease is primarily transmitted through contact with animals or through exposure to contaminated water or soil 3

Treatment of Leptospirosis

  • The optimal antimicrobial treatment for leptospirosis has not been established 2
  • Commonly used antibiotics for treating leptospirosis include penicillin, doxycycline, cefotaxime, ceftriaxone, and azithromycin 2, 4
  • A meta-analysis found no effect of penicillin treatment on mortality compared to placebo, and no differences between penicillin and cephalosporins or doxycycline 4
  • A case report found that combined doxycycline and ceftriaxone therapy was effective in treating leptospirosis 3

Efficacy of Antibiotics

  • The evidence is very uncertain about the effect of antibiotics on all-cause mortality, serious adverse events, or adverse events considered non-serious 5
  • A systematic review found that antibiotics may be useful in treating leptospirosis, but the evidence is insufficient to provide clear guidelines for practice 6, 5
  • The certainty of evidence is very low, and there is a lack of definitive rigorous data from randomized trials to support the use of antibiotics for treating leptospirosis infection 5

Chemoprophylaxis

  • A weekly dose of 200 mg of doxycycline does not show benefit versus placebo regarding the number of new cases of symptomatic leptospirosis 4
  • A single dose of doxycycline at exposure to flood water could have a beneficial effect 4
  • None of the other chemoprophylaxis regimens tested have shown a statistically significant effect on the number of new symptomatic cases 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Antimicrobial therapy of leptospirosis.

Current opinion in infectious diseases, 2006

Research

Antibiotics for treatment of leptospirosis.

The Cochrane database of systematic reviews, 2024

Research

Antibiotics for treating leptospirosis.

The Cochrane database of systematic reviews, 2000

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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