What is Leptospirosis?

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From the Guidelines

Leptospirosis requires prompt antibiotic treatment as soon as it is suspected, without waiting for laboratory confirmation, to improve outcomes and prevent complications. For mild cases, oral doxycycline or penicillin antibiotics are thought to be effective during the bacteraemic phase 1. However, for severe cases requiring hospitalization, such as those presenting with classical symptoms and signs of Weil's disease like jaundice, intravenous penicillin G or ceftriaxone may be preferred, although the evidence for antibiotic effectiveness in established leptospirosis is limited 1.

Key Considerations

  • Leptospirosis can present with a wide range of symptoms, from mild flu-like illness to severe disease with organ failure, characterized by haemorrhage, jaundice, and hepatorenal failure (Weil’s disease) 1.
  • The disease classically follows a biphasic course, with an initial bacteraemic phase and a subsequent immune phase 1.
  • Conjunctival suffusion is a suggestive symptom, and patients may also experience fever, myalgia, hepatorenal syndrome, and haemorrhage 1.
  • Treatment should be initiated promptly, and supportive care including hydration, fever management, and monitoring for complications like kidney failure or respiratory distress is essential.

Prevention and Control

  • Prevention involves avoiding contact with potentially contaminated water or soil, especially after flooding, wearing protective clothing when exposed to animal urine, and controlling rodent populations.
  • Leptospirosis spreads through contact with water, soil, or food contaminated with the urine of infected animals, particularly rodents, and the bacteria enter the body through cuts, mucous membranes, or conjunctiva.

Evidence-Based Recommendation

The most effective approach to managing leptospirosis is prompt recognition and treatment with antibiotics, as well as supportive care to prevent complications. While the evidence for antibiotic effectiveness in established leptospirosis is limited, most infectious disease specialists continue to recommend antibiotics, especially for severe cases 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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