SARS (severe acute respiratory syndrome) is caused by the SARS coronavirus, known as SARS CoV. Coronaviruses commonly cause infections in both humans and animals.

There have been 2 self-limiting SARS outbreaks, which resulted in a highly contagious and potentially life-threatening form of pneumonia. Both happened between 2002 and 2004.

Since 2004, there have not been any known cases of SARS reported anywhere in the world.

The World Health Organization (WHO) continues to monitor countries throughout the world for any unusual disease activity. If there was another SARS outbreak, it should be possible to limit the spread of infection.

The SARS pandemic

SARS originated in China in 2002. It is thought that a strain of the coronavirus usually only found in small mammals mutated, enabling it to infect humans.

The SARS infection quickly spread from China to other Asian countries. There were also a small number of cases in several other countries, including 4 in the UK, plus a significant outbreak in Toronto, Canada.

The SARS pandemic was eventually brought under control in July 2003, following a policy of isolating people suspected of having the condition and screening all passengers travelling by air from affected countries for signs of the infection.

During the period of infection, there were 8,098 reported cases of SARS and 774 deaths. This means the virus killed about 1 in 10 people who were infected. People over the age of 65 were particularly at risk, with over half of those who died from the infection being in this age group.

In 2004 there was another smaller SARS outbreak linked to a medical laboratory in China. It was thought to have been the result of someone coming into direct contact with a sample of the SARS virus, rather than being caused by animal-to-human or human-to-human transmission.

Key Facts

1. SARS is the febrile “severe acute respiratory syndrome” that first appeared in 2003 and spread rapidly to more than two dozen countries across the world, infecting over 8,000 people and killing 774 before it could be contained in 2004.
2. SARS is caused by a coronavirus (SARS-CoV) that exists in bats and palm civets in Southern China.
3. This infection can be spread easily from close person-to-person contact (such as living in the same household) via respiratory droplets that come in contact with skin or mucous membranes (eyes, mouth, or nose).
4. Infected people become ill within a week of exposure. During the first week, nonspecific symptoms of a flu-like illness begin. This period is followed by a syndrome of “atypical” pneumonia, including dry cough, and progressively worsening shortness of breath with poor oxygenation.
5. Since these are nonspecific symptoms and findings, the diagnosis of SARS is only considered if the individual has also had specific risk factors within 10 days prior to illness.
6. If there are grounds for suspicion, respiratory secretions are sent for testing at the CDC.
7. There is no medication that is known to treat SARS. Treatment is supportive.
8. During the 2003 outbreak, approximately 25% of people had severe respiratory failure and 10% died.
9. The SARS outbreak in 2002-2003 was controlled solely by using public-health measures, such as wearing surgical masks, washing hands well, and isolating infected patients.
10. Two other coronavirus types are related to SARS, MERS and Wuhan coronavirus. They can cause severe infections in humans.