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Leptospirosis A054

Document
Last amended 
28 April 2020
Current RMA Instruments
Reasonable Hypothesis SOP
94 of 2014
Balance of Probabilities SOP
95 of 2014
Changes from previous Instruments

SOP Bulletin 178

ICD Coding
  • ICD-9-CM Codes: 100, 100.0, 100.8, 100.81, 100.89, 100.9
  • ICD-10-AM Codes: A27
Brief description

This is a clinical illness caused by infection with spirochaetes (a type of bacteria) of the genus Leptospira.  There are at least 10 pathogenic species in the genus.  Leptospirosis is mostly a disease of the tropics.  It results from contact with host animals or contaminated environmental sources.  The illness is typically flu-like, mild and self-limiting.  More severe and potentially fatal cases may occur, with involvement of the liver, kidney, nerves and  muscles, severe pulmonary manifestations and vasculitis.

Confirming the diagnosis

This diagnosis is usually made on a combination of clinical grounds and serology.  Molecular tests (PCR and LAMP) are becoming increasingly available. The causative organism may also be cultured (grown) from blood and urine.

The relevant medical specialist is an infectious disease physician.

Additional diagnoses covered by SOP
  • Weil’s disease / syndrome

  • Weil-Vasiliev disease

Other labels that may be covered by SOP (more information required)
  • Cane-cutter fever, canicola fever, mud fever, nanukayami fever, rice-field fever, swamp fever, swineherd's disease, waterborne fever
Conditions excluded from SOP
  • Asymptomatic leptospiral infection
Clinical onset

The usual presentation is with an abrupt onset of fever, rigors, myalgia and headache, an average of 10 days after exposure to the organism.

Clinical worsening

Many cases resolve without specific treatment.  More severe cases may require hospitalisation and intravenous antibiotics.  i