Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus. SARS was first reported from the Guangdong Province in China in 2002. Labelled as the first pandemic of the 21st century, SARS spread to 29 countries with more than more than 8000 cases.
Since 2003, SARS has reappeared on four counts: Three times from lab accidents (Singapore and Chinese Taipei), and once in southern China where the source of infection remains undetermined although there is circumstantial evidence of animal-to-human transmission (WHO).
- SARS is caused by the SARS-associated coronavirus (SARS-CoV).
- Animals eaten as exotic foods in southern China, particularly the palm civet, may be intermediate hosts.
- Transmission: Humans acquire the infection from close person-to-person contact via droplet spread. The virus may also spread via contaminated surfaces or objects. Lack of or inadequate infection control precautions facilitate spread of the virus. Transmission mainly occurs during the 2nd week of illness, when the excretion of the virus in respiratory secretions and stool is at its peak.
- The incubation period for SARS is 2-7 days.
- Clinical presentation: A patient with SARS presents as a prodrome of high fever (>100.4°F), malaise, myalgia, headache, diarrhea, shivering followed by respiratory symptoms – cough (dry, nonproductive cough), shortness of breath. Chest x-ray may show lesion suggestive of pneumonia. Severe disease may progress to respiratory distress necessitating intensive care.
- Patients are most contagious during the 2nd week of illness
- Diagnosis: Polymerase chain reaction (PCR) and/or antibody detection (IgG and IgM) via ELISA (Enzyme-linked ImmunoSorbent Assay) or IFA (Immunofluorescence Assay) or virus isolation in cell cultures. Specimens include blood, stool, respiratory secretions or body tissues. A negative PCR does not exclude SARS. The samples may not have been collected at a time when the virus or its genetic material was present. PCR test must be done at the earliest and repeated if symptoms persist.
- Management: Supportive care with antipyretics, oxygen supplementation (mechanical ventilation when indicated), isolation of patient, strict barrier nursing and infection control practices including personal protective equipment when in close contact with the patient. Antiviral drugs or steroids are not recommended.
(Source: WHO, CDC, Uptodate)