Severe Acute Respiratory Syndrome (SARS)

Last Updated 11/02/2020

Authors:Angel Coz, MD, FCCP; Margaret A. Disselkamp, MD

About Severe Acute Respiratory Syndrome (SARS)

Key facts about Severe Acute Respiratory Syndrome
  • Severe Acute Respiratory Syndrome (SARS) is caused by a coronavirus, the family of viruses that causes the common cold.
  • SARS is a respiratory illness that progresses rapidly and spreads from person to person.
  • An outbreak of SARS started in 2003 in China but spread worldwide before it was contained.
  • There have been no reported cases of SARS anywhere in the world since 2004.

SARS is an infectious virus that can cause serious respiratory illness or death. It can be spread from person to person. An outbreak of SARS occurred in 2002 to 2003 and started in China, but it spread worldwide and caused almost 1 out of every 10 people who were infected to die. SARS is highly contagious; it’s spread by respiratory droplets or contact with other bodily fluids.

How SARS affects your body

SARS infection initially causes a fever (above 100.4°F [38°C]), headache, and fatigue. Respiratory symptoms include a dry cough and shortness of breath that develop 2 to 7 days after the first symptoms. Most patients have a lung infection, or pneumonia, that can be seen on a chest X-ray by days 7 to 10. Some patients become very sick and need a breathing machine, or ventilator, to breathe for them.

How serious is Severe Acute Respiratory Syndrome?

Infection with SARS is life threatening, especially in adults older than 60 years of age. Overall, 1 out of 10 patients infected with SARS will die, and 1 out of 2 of patients over the age of 60 will die. Most people infected with the SARS virus develop a serious infection and will need to go to the hospital.

Symptoms of SARS

SARS symptoms range from almost nothing to severe infection and death. Overall, SARS causes symptoms that are similar to those of influenza (the flu). However, these symptoms may progress, and 70% of patients develop a serious respiratory illness.

The most common symptoms of SARS are:

Contact your health care provider if you have these symptoms.

What causes SARS?

SARS is caused by a coronavirus. Coronavirus is one of the most common types of virus that causes what we call the common cold.

What are risk factors for SARS?

You are at greater risk for infection if you have been exposed to someone who is infected with the virus or you have traveled to an area where the virus is spreading. People at greater risk for severe infection are usually older (older than 60 years of age); have unusual symptoms; are male; or have other medical conditions, including diabetes and chronic hepatitis B. Health care workers are at greater risk of infection because they are exposed to infected patients.

Diagnosing SARS

The Centers for Disease Control and Prevention (CDC) has published guidelines for when health care providers should suspect SARS.

Lab tests to detect the SARS virus include a blood test, a nasal swab, a stool or urine sample, or growing the virus in culture. Chest X-rays or computed tomography (CT) scans can show if patients have pneumonia with SARS. Your provider may order these tests if you have SARS-related symptoms, have had close contact within 10 days with a person suspected of having SARS, or have traveled within 10 days to an area known to have the SARS virus.

When should you see your health care provider?

See your health care provider if you have:

  • Been to an area where there is a SARS outbreak;
  • Been exposed to someone who has traveled to an area with SARS virus; or
  • A fever of above 100.5°F, a cough, chest pain, or difficulty breathing.

Try to avoid exposure to other people, and stay away from public areas until you know you don’t have SARS. Even if you only have mild symptoms, you should report a possible SARS virus infection to your health care provider to help control the spread of the infection.

Treating SARS

Currently, no medication can treat SARS. Many treatments have been studied, but because the infection spreads quickly and is not controlled, no definite treatment has been found.

If you have mild illness, you can stay at home and try not to spread the virus to other people. Ask your health care provider about any medicines you can take to manage symptoms, such as cough, fever, or a runny nose.

If you have more severe illness, you may need to go to the hospital, where you will be treated with fluids, oxygen therapy, and possibly antibiotics to treat any secondary bacterial infections. Patients in the hospital for SARS are isolated from other people to prevent the spread of the virus.

Managing SARS

SARS can be a rapidly progressing respiratory illness. There are only a few cases of SARS in patients with no or mild symptoms. Most patients (70%) develop persistent or recurrent fever and shortness of breath, but about 30% of people have significant improvement in 1 week.

About 25% of hospitalized patients will have severe illness and need to stay in an intensive care unit. However, most people fully recover from their illness.

Preventing SARS

The best way to prevent SARS is by washing your hands with soap and water, wearing a face mask, and avoiding contact with people infected with the virus. The virus can survive on surfaces for as long as 6 days. It can be killed by washing surfaces with bleach or other household cleaners.

If you are caring for someone at home with SARS, limit exposure to them as much as possible. Do not share silverware, bedding, or clothing unless they have been washed with hot water and soap.

If you have SARS, you are more likely to spread the virus to others after symptoms have started. You are most contagious between 7 and 10 days after symptoms begin, but you can be contagious for up to 2 weeks. Avoid contact with other people as much as possible until 10 days after your symptoms have stopped.


Patients with long-term effects from SARS infection will typically develop respiratory symptoms. There are many support groups online for patients with long-term respiratory problems. Check the American Lung Association website for more information.

Questions to ask your health care provider

Making notes before your visit and taking along a trusted family member or friend can help you through the first appointment with your provider.

Ask your provider questions such as the following:

  • What should I do if I think I have SARS?
  • What should I do if I think someone close to me has SARS?
  • How can I prevent SARS?