Table 3.

WHO case definitions for severe acute respiratory syndrome.

Clinical definition of SARS

A person with a history of:

Fever (≥38 °C)

AND

One or more symptoms of lower respiratory tract illness (cough, difficulty breathing, shortness of breath)

AND

Radiographic evidence of lung infiltrates consistent with pneumonia or RDS OR autopsy findings consistent with the pathology of pneumonia or RDS without an identifiable cause

AND

No alternative diagnosis can fully explain the illness

Laboratory definition of SARS

A person with symptoms and signs that are clinically suggestive of SARS AND with positive laboratory findings for SARS-CoV based on one or more of the following diagnostic criteria:

(a) PCR positive for SARS-CoV using a validated method from:

•At least two different clinical specimens (e.g. nasopharyngeal and stool) OR

•The same clinical specimen collected on two or more occasions during the course of the illness (e.g. sequential nasopharyngeal aspirates) OR

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

(b) Seroconversion by ELISA or IFA

•Negative antibody test on acute serum followed by positive antibody test on convalescent phase serum tested in parallel OR

•Four-fold or greater rise in antibody titre between acute and convalescent phase sera tested in parallel

(c) Virus isolation

•Isolation in cell culture of SARS-CoV from any specimen AND PCR confirmation using a validated method