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Severe Acute Respiratory Syndrome (SARS)

What Is Severe Acute Respiratory Syndrome (SARS)?

Severe acute respiratory syndrome (SARS) has been a life-threatening viral respiratory illness caused by a coronavirus known as SARS-associated coronavirus (SARS-CoV) but usually shortened to SARS or SARS virus). SARS was associated with a flu-like syndrome, which progressed into pneumonia, respiratory failure, and sometimes death in some patients. The SARS virus is believed to have originated in the Guangdong Province in Southern China and had subsequently spread around the world in small outbreaks that have ceased since 2004. China and its surrounding countries have witnessed the greatest numbers of SARS-related cases and death.

The history of SARS is short. The SARS virus was first reported in 2002 in Asia and cases were reported until mid-year 2003. According to the World Health Organization (WHO), as of July 2003, a total of 8,437 people worldwide became ill with SARS and 813 died during the outbreak or epidemic. Illness was reported in more than 30 countries and on five continents. Only eight people in the United States acquired SARS infection, and all of these people had traveled outside of the U.S. No deaths due to SARS occurred in the U.S. The good news about SARS was that no outbreaks or epidemics have occurred since 2004.

Because of the rapid and unexpected spread of SARS, and because little is known about the virus, the U.S. Centers for Disease Control and Prevention (CDC) and the WHO have continued to closely monitor any outbreaks that result in a SARS-like illness. Guidelines and medical information about SARS can be found at the CDC and WHO web sites.

What Is the Cause of SARS?

The SARS virus spreads by close person-to-person contact. Transmission likely occurs by droplets produced when an infected person sneezes or coughs. Droplet spread can occur when airborne droplets, produced by a cough or sneeze, are deposited on the mucous membranes of the mouth, nose, or eyes of a person up to 3 feet away. The virus can also be spread when a person touches a surface contaminated with the droplets, as was found on many hospital surfaces, including elevator buttons. Oral-fecal transmission of SARS may also occur. Unprotected health-care workers were at significant risk of acquiring the infection during the outbreaks.

SARS virus replicates in both the lungs and gastrointestinal tract tissues. However, tissue samples show the most damage occus in the lung alveoli (air sacs) where lung function is compromised, producing a severe breathing disorder often termed acute respiratory distress syndrome (ARDS).

Medically Reviewed by a Doctor on 12/21/2016

SARS Complications


Pneumonia is an infection or inflammation of the lungs. It can be in just one part of the lungs, or it can involve many parts. Pneumonia is caused by bacteria, viruses, fungi, and other microorganisms. The severity of pneumonia depends on which organism is causing the infection and the immune response of the individual to that infection. Viral pneumonias are usually not very serious, but they can be life-threatening in very old and very young patients and in people whose immune systems are weak.

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Severe Acute Respiratory Syndrome (SARS) »

Severe acute respiratory syndrome (SARS) is a serious, potentially life-threatening viral infection caused by a previously unrecognized virus from the Coronaviridae family.

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