Severe acute respiratory syndrome is a viral infection that causes flu-like symptoms.

Severe acute respiratory syndrome (SARS) was first detected in China in late 2002. A worldwide outbreak occurred, resulting in almost 8,500 cases in 29 countries, including Canada and the United States, by mid 2003. As of mid 2006, no cases had been reported worldwide since 2004.

Symptoms and Diagnosis

Symptoms begin about 2 to 10 days after contact with the virus. The first symptoms resemble those of other more common infections and include fever, headache, chills, and muscle aches. Runny nose and sore throat are unusual. About 3 to 7 days later, a dry cough and difficulty breathing may develop. Most people recover within 1 to 2 weeks. However, about 10 to 20% develop severe difficulty breathing, resulting in insufficient oxygen in the blood. About half of these people need assistance with breathing. However, few people in the United States have had symptoms this severe.

About 10% of infected people die. Death is due to extreme difficulty breathing.

SARS is suspected only if people who may have been exposed to an infected person have a fever plus a cough or difficulty breathing. If a doctor suspects SARS, a chest x-ray is usually taken. The doctor may take a swab of secretions from the person's nose and throat to try to identify the virus. A sample of sputum may also be examined.

Prevention and Treatment

Travel advice from the Centers for Disease Control and Prevention (CDC) should be heeded. Wearing a mask is not recommended except for people who are in close contact with someone who may have SARS. People exposed to someone who may have SARS (such as family members, airline personnel, or health care workers) should be alert for symptoms of the infection. If they have no symptoms, they may attend work, school, and other activities as usual. If they develop fever, headache, chills, muscle aches, cough, or difficulty breathing, they should avoid face-to-face contact with other people and see a doctor.

If doctors think a person may have SARS, the person is isolated in a room with a ventilation system that limits the spread of microorganisms in the air.

Doctors may try treating SARS with antiviral drugs, such as oseltamivir and ribavirin, and corticosteroids. However, there is no evidence that these or any other drugs are effective. The virus eventually disappears. People with mild symptoms need no specific treatment. Those with moderate difficulty breathing may need to be given oxygen through plastic nasal prongs or a face mask. Those with severe difficulty breathing may need mechanical ventilation to aid breathing.

Last full review/revision November 2009 by Marguerite A. Urban, MD