Case Definition for Severe Acute Respiratory Syndrome (SARS)

Print Friendly, PDF & Email

Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus, called SARS-associated coronavirus (SARS-CoV).

Clinical Criteria

Early illness

  • Presence of two or more of the following features: fever (might be subjective), chills, rigors, myalgia, headache, diarrhea, sore throat, rhinorrhea

Mild-to-moderate respiratory illness

  • Temperature of >100.4º F (>38º C) and
  • One or more clinical findings of lower respiratory illness (e.g., cough, shortness of breath, difficulty breathing)

Severe respiratory illness

  • Meets clinical criteria of mild-to-moderate respiratory illness, and
  • One or more of the following findings:
    • Radiographic evidence of pneumonia, or
    • Acute respiratory distress syndrome, or
    • Autopsy findings consistent with pneumonia or acute respiratory distress syndrome without an identifiable cause

Epidemiologic Criteria

Possible exposure to SARS-associated coronavirus (SARS-CoV)
One or more of the following exposures in the 10 days before onset of symptoms:

  • Travel to a foreign or domestic location with documented or suspected recent transmission of SARS-CoV or
  • Close contact with a person with mild-to-moderate or severe respiratory illness and with history of travel in the 10 days before onset of symptoms to a foreign or domestic location with documented or suspected recent transmission of SARS-CoV

Likely exposure to SARS-CoV
One or more of the following exposures in the 10 days before onset of symptoms:

  • Close contact with a confirmed case of SARS-CoV disease or
    Close contact with a person with mild-moderate or severe respiratory illness for whom a chain of transmission can be linked to a confirmed case of SARS-CoV disease in the 10 days before onset of symptoms

Laboratory Criteria
Tests to detect SARS-CoV are being refined, and their performance characteristics assessed; therefore, criteria for laboratory diagnosis of SARS-CoV are changing. The following are the general criteria for laboratory confirmation of SARS-CoV:

  • Detection of serum antibody to SARS-CoV by a test validated by CDC (e.g., enzyme immunoassay [EIA]), or
  • Isolation in cell culture of SARS-CoV from a clinical specimen, or
  • Detection of SARS-CoV RNA by a reverse-transcription-polymerase chain reaction (RT-PCR) test validated by CDC and with subsequent confirmation in a reference laboratory.

Exclusion Criteria
A person may be excluded as a SARS report under investigation (SARS RUI), including as a CDC-defined probable SARS-CoV case, if any of the following applies:

  • An alternative diagnosis can explain the illness fully
  • Antibody to SARS-CoV is undetectable in a serum specimen obtained > 28 days after onset of illness
  • The case was reported on the basis of contact with a person who was excluded subsequently as a case of SARS-CoV disease; then the reported case also is excluded, provided other epidemiologic or laboratory criteria are not present

 

References:

  1. Hui DSC, Zumla A. Severe Acute Respiratory Syndrome: Historical, Epidemiologic, and Clinical Features. Infect Dis Clin North Am. 2019;33(4):869–889. [Medline]
  2. Wang Y, Wang Y, Chen Y, Qin Q. Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures. J Med Virol. 2020;10.1002/jmv.25748. [Medline]
  3. CDC. Severe Acute Respiratory Syndrome (SARS). Acceded Mar 2020 [Website]

Created Mar 26, 2020.