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Medical Author:

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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In this Article

• Severe acute respiratory syndrome (SARS) facts
• What is severe acute respiratory syndrome (SARS)?
• What causes SARS? How is SARS transmitted?
• What are risk factors for SARS?
• What are SARS symptoms and signs?
• How is SARS diagnosed?
• What is the treatment for SARS?
• What is the prognosis of SARS?
• Can SARS be prevented?
• Where can people get more information about SARS?
• Severe Acute Respiratory Syndrome (SARS) Index

SARS is an infectious respiratory illness caused by a virus. The first cases of SARS occurred in late 2002 in the Guangdong Province of the People's Republic of China. Because of the contagious nature of the disease and the delayed public-health response, the epidemic spread rapidly around the globe. Final statistics from the World Health Organization showed 8,096 reported illnesses and 774 deaths.

The rapid transmission and high mortality rate (about 10%) of SARS drew international attention and concern. Fortunately, efforts to identify and quarantine infected people proved highly effective. By July 2003, sustained human-to-human transmission of SARS had been eliminated. This was a public-health triumph that is often underappreciated. Although illnesses such as anthrax, bird flu, or West Nile virus are potential threats, SARS was a very real problem. Unfortunately, future outbreaks of SARS are still possible because the virus lives in some wild bats and civets in China and also exists in laboratory cultures. In fact, there were a few human cases of SARS in 2004 as a result of laboratory accidents in the People's Republic of China.

SARS is caused by a virus referred to as "SARS-CoV" from the coronavirus genus; SARS-CoV means severe acute respiratory syndrome-associated coronavirus. The genus coronavirus includes viruses that infect animals and a few that cause the common cold in humans. However, the SARS-CoV virus is different than other coronaviruses and had never been identified before 2002. This was not entirely surprising because there are many types of coronaviruses and they are known to mutate easily.

Although scientists are not certain, it has been suggested that the SARS virus originated in wild bats and then spread to palm civets or similar mammals. The virus then gradually mutated until it could infect humans. There was ample opportunity for the virus to come into contact with humans. Bats serve as a food source in parts of Asia, and their feces are sometimes used in folk medicines. Civets are catlike mammals that live in the tropics of Africa and Asia and produce musk from their scent glands, which is used in perfumes. Civets are also hunted for meat in some parts of the world.

SARS-CoV is spread from person to person through respiratory secretions. SARS often affected people caring for a sick individual and spread readily through health-care facilities until infection-control measures were established. During the outbreak, one in about every 20 infected people was a health-care worker who cared for a patient with SARS.