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Last reviewed: 28 Oct 2023
Last updated: 09 Aug 2023



History and exam

Key diagnostic factors

  • high remittent fever
  • headache
  • myalgia
  • conjunctival suffusion
  • muscle tenderness
More key diagnostic factors

Other diagnostic factors

  • chills or rigors
  • abdominal pain
  • nausea or vomiting
  • diarrhea
  • asthenia
  • anorexia
  • photophobia
  • eye pain
  • neck stiffness
  • cough
  • dyspnea
  • chest pain
  • hemoptysis
  • oliguria or polyuria
  • cardiac arrhythmias
  • lymphadenopathy
  • splenomegaly
  • hepatomegaly
  • jaundice
  • adenopathy
  • mental status changes
  • morbilliform rash
Other diagnostic factors

Risk factors

  • contact (direct or indirect) with urine of infected animals
  • residence in or travel to an endemic area
  • residence in or travel to an area with recent flooding
  • involvement in water sports
  • poor living conditions/lack of sanitation
More risk factors

Diagnostic investigations

1st investigations to order

  • CBC and differential
  • urinalysis
  • microscopic agglutination test (MAT)
  • enzyme-linked immunosorbent assay (ELISA)
  • polymerase chain reaction (PCR)
  • darkfield examination
  • blood culture
  • cerebrospinal fluid (CSF) culture
  • ECG
  • chest x-ray
  • LFTs
  • conjugated bilirubin
  • metabolic profile
  • serum pancreatic enzymes
  • CSF analysis
More 1st investigations to order

Investigations to consider

  • urine culture
  • renal biopsy
  • lung biopsy
  • staining methods
  • latex agglutination
  • western blot
  • quantitative PCR
More investigations to consider

Emerging tests

  • lateral flow assays
  • cytokines

Treatment algorithm


mild disease

moderate to severe disease



John Fournier, MD

Clinical Fellow

Infectious Disease Section

Yale School of Medicine

New Haven



JF declares that he has no competing interests.

Albert I. Ko, MD

Professor of Epidemiology and Medicine

Department Chair

Epidemiology of Microbial Diseases

Yale School of Public Health

New Haven



AIK serves as an expert panel member for the Reckitt Global Hygiene Institute and a Board of Directors member for the American Society of Tropical Medicine. He has received grants from Zoetis and has patents which have been awarded and submitted for use in developing diagnostics and vaccines for leptospirosis.


Dr John Fournier and Dr Albert I. Ko would like to gratefully acknowledge Dr Nilmarie Guzman, a previous contributor to this topic.


NG declares that she has no competing interests.

Peer reviewers

Carmen Isache, MD

Assistant Professor of Medicine

Infectious Disease Division

University of Florida College of Medicine




CI declares that she has no competing interests.

Andreas Jansen, MD, DTM

Scientific Officer

Robert Koch Institute

Department for Infectious Disease Epidemiology

Gastrointestinal Infections

Zoonoses and Tropical Infections Unit




AJ declares that he has no competing interests.

Sean V. Shadomy, DVM, MPH


Bacterial Zoonoses Branch


Centers for Disease Control and Prevention




SVS declares that he has no competing interests.

  • Leptospirosis images
  • Differentials

    • Hantavirus cardiopulmonary syndrome
    • Dengue fever
    • Malaria infection
    More Differentials
  • Guidelines

    • CDC Yellow Book: health information for international travel - leptospirosis
    • Fever in returned travellers presenting in the United Kingdom: recommendations for investigation and initial management
    More Guidelines
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