Severe acute respiratory syndrome (SARS) case definition

This document contains the case definitions for Severe acute respiratory syndrome which is nationally notifiable within Australia. This definition should be used to determine whether a case should be notified.

Page last updated: 12 March 2004

Australian national notifiable diseases case definitions - Severe acute respiratory syndrome (SARS)


Only confirmed cases should be notified. (Note: A surveillance case definition for probable cases is currently in preparation)

Confirmed case

A confirmed case requires Laboratory definitive evidence AND clinical evidence.

Laboratory definitive evidence

1. Detection of Severe acute respiratory syndrome-coronavirus (SARS-CoV) by nucleic acid testing using a validated method from at least two different clinical specimens (eg nasopharyngeal and stool)


the same clinical specimen collected on two or more occasions during the course of the illness (eg sequential nasopharyngeal aspirates)


two different assays or repeat PCR using a new RNA extract from the original clinical sample on each occasion of testing


2. Seroconversion or significant increase in antibody level or fourfold or greater rise in titre to SARS-CoV tested in parallel by enzyme-linked immunosorbent assay or immunofluorescent assay


3. Isolation of SARS-CoV


detection of SARS-CoV by nucleic acid testing using a validated method.

Clinical evidence

A person with a history of:

• Fever (38 C), AND

• One or more symptoms of lower respiratory tract illness (cough, difficulty breathing), AND

• Radiographic evidence of lung infiltrates consistent with pneumonia or Acute Respiratory Distress Syndrome (ARDS) OR autopsy findings consistent with the pathology of pneumonia or ARDS.


The NNDSS definition is based on that provided by WHO for use in the inter-outbreak period. It should be recognised that the case definition provided by WHO may be modified in the event of a second global alert.

Until the epidemiology of SARS has been further defined, 'alert cases' (see below) should be reported to State and Territory Health Departments, and informally reported to the Australian Government Department of Health and Ageing. The aim of the alert cases is to provide early warning of the potential recurrence of SARS to:

• rapidly implement appropriate infection control measures

• expedite diagnosis

• activate the public health response.

Alert case

In the absence of an alternate diagnosis:

1. Two or more health care workers in the same health care unit fulfilling the clinical case definition of SARS and with onset of illness in the same 10-day period.


2. Hospital acquired illness in three or more persons (health care workers and/or other hospital staff and/or patients and/or visitors) in the same health care unit fulfilling the clinical case definition of SARS and with onset of illness in the same 10-day period.

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