What Is SARS?

Medically Reviewed by Zilpah Sheikh, MD on February 08, 2024
5 min read

Severe acute respiratory syndrome, or SARS, is a potentially deadly illness that started in China and quickly spread around the world in 2003. It's caused by a virus called SARS-associated coronavirus (SARS-CoV) which gives you flu-like symptoms. SARS was the first serious and easily transmitted new disease of the 21st century, but not the last.



SARS first sprang to the world’s attention in early 2003, though the first cases were reported in China in late 2002. 

Its origins were linked to horseshoe bats living in caves in mainland China. These bats harbor a coronavirus similar to that of SARS. The theory is that the bats infected civet cats, which were sold for food at live animal markets in the country. People were infected not from eating the civets but from touching the animals as they raised or killed them.

Over the first half of 2003, more than 8,000 people got sick in an outbreak that spread to 26 countries. Nearly 800 people died. Doctors and scientists tracked the disease to southeastern China, near Hong Kong. From there, travelers carried SARS to other countries in Asia, such as Vietnam and Singapore, as well as to Europe and Canada.

Public health officials around the world scrambled to contain the outbreak, and there've been no reported cases since 2004.

SARS is caused by a virus that takes over your body’s cells and uses them to make copies of itself. The SARS virus is from a group of viruses known as coronaviruses, which also cause the common cold.

SARS spreads when people who have it cough or sneeze, spraying tiny droplets of liquid containing the virus to other people within 2-3 feet. Some may get the virus by touching something those droplets hit, then touching their nose, eyes, or mouth. Someone with SARS isn't contagious before symptoms appear.

If you live with or are in close contact with someone who has SARS, you're more likely to get it than if you're just passing by or sitting in a waiting room across from them. "Close contact" means hugging or kissing someone, talking with them less than 3 feet away, or sharing a knife, fork, or spoon with them.

The symptoms of SARS start off similar to those of the flu. They may include:

  • A fever over 100.4 F (38 C)
  • Chills
  • Muscle aches
  • Shortness of breath

About 1 in 5 people with SARS may also get diarrhea.

But the symptoms can get worse fast. SARS causes a dry cough that shows up anywhere from 2 to 7 days into the illness. This cough can keep your body from getting enough oxygen, and more than 1 in 10 people with SARS need a machine to help them breathe.

SARS can lead to other health problems, including pneumonia, heart failure, and liver failure. People who are over 60 and have ongoing illnesses like diabetes or hepatitis are most likely to have these problems.

At the time of the SARS outbreak, there weren't any ways to test for it. Usually, a diagnosis was made from looking at your symptoms and asking whether you'd traveled to certain parts of Asia or been in close contact with someone suspected of having SARS.

 Now we can check for SARS with:

  • Blood tests
  • Stool tests
  • Nasal swab tests

SARS-related pneumonia can be diagnosed with CT scans or X-rays of the chest. 


At the time of the original outbreak, there were no targeted treatments available for SARS. Antiviral drugs like ribavirin and lopinavir/ritonavir were used. So were corticosteroids (commonly known as steroids). The best treatment strategy for SARS remains unknown. 

People with SARS were mostly given supportive care, such as antibiotics to fight off other infections while they recovered, or steroids to reduce swelling in the lungs. In serious cases, they could be given blood plasma from someone who already recovered from SARS and whose plasma would have antibodies.

If their symptoms were mild, they recovered at home, taking over-the-counter medications for a fever or muscle aches. But if the symptoms got worse, they may have gone to a hospital for more treatment, like getting fluids or oxygen.


There’s no cure for SARS. You can lower your chances of getting it with some simple steps:

  • Wash your hands often with soap and water, or use an alcohol-based hand sanitizer.
  • Don’t touch your eyes, nose, or mouth with dirty hands.
  • Wear disposable gloves if you have contact with someone’s pee, poop, saliva, or other body fluids.
  • Wipe surfaces like countertops with disinfectants, and wash personal items with soap and hot water.
  • If you’re around someone with SARS, wear a surgical mask to cover your nose and mouth.
  • Don't share eating and drinking utensils, towels, or bedding with someone who has SARS, unless you've washed the items first with soap and hot water.
  • If you're talking to someone with SARS, stay at least 3 feet away.
  • Keep children home from school if they get a fever or breathing problems.

Take all these precautions for 10 days after the SARS patient's symptoms have disappeared.


The SARS virus is spread by people who have SARS coughing and sneezing on you. The best way to prevent it is to practice good hygiene and wear a mask when you're around someone who has it. There's no known cure for it.

Are COVID and SARS related?

Yes. Both originated in China, are believed to have come from bats, and are caused by coronaviruses. The SARS virus is called SARS-CoV-1 or SARS-CoV, and the COVID-19 virus is called SARS-CoV-2. Both infections are spread the same way (via droplets from coughing or sneezing). One big difference is that SARS infected fewer people (8,096 cases, mostly in Asia) but was more severe, while COVID infected far more people (119,512,530 worldwide), but most of the cases had mild to moderate symptoms.