Questions About Severe Acute Respiratory Syndrome (SARS)
Revised April 23, 2003
A respiratory illness has emerged in recent months in Canada,
China, Hong Kong Special Administrative Region of China, Indonesia, Philippines, Singapore, Thailand, and Vietnam, presenting a worldwide public health concern. This atypical
pneumonia has been named Severe Acute Respiratory Syndrome (SARS) by World Health Organization (WHO).
SARS is an infectious disease of the respiratory system characterized by atypical inflammation of the lungs
(pneumonia). Scientists at CDC and other laboratories have detected a previously unrecognized coronavirus in patients with SARS. This new coronavirus is the leading hypothesis for
the cause of SARS, however, other viruses are still under investigation as potential causes.
SARS appears to be primarily spread from person-to-person through droplet transmission when in direct close contact
with a person with SARS. Medical personnel have been encouraged to implement airborne and contact infection control precautions until all routes of transmission have been
identified. SARS is an emerging disease. Knowledge about its clinical behavior, response to treatment, and modes and risks of transmission are continually evolving.
Early symptoms in patients with this SARS have included fever (>100°F), muscle aches, dry cough, shortness of
breath, or difficulty breathing. In some cases these symptoms may progress to insufficient blood to the brain, requiring the use of a respirator.
No specific treatment recommendations can be made at this time; however, medical personnel are instructed to treat
general clinical signs. The virus suspected to be the cause of SARS (coronavirus) is being tested against various antiviral drugs to see if an effective treatment can be found.
As of April 22, 2003, WHO has received reports of more than
4288 new suspected cases of Severe Acute Respiratory Syndrome (SARS) with 251 deaths. Reports to date have been received from 25 countries and include—Canada, China,
Hong Kong Special Administrative Region of China, Indonesia, Philippines, Singapore, Thailand, and Vietnam. In the United States, as of April 22, 2003, there are currently 239 cases
under investigation representing 202 suspect cases and 37 probable cases.
The outbreaks appear to primarily involve health-care workers and direct, close family contacts to suspect cases.
*It is anticipated that the geographic distribution information can change. For the most up-to-date disease surveillance,
please check case information at:
For information on US cases see:
QUESTIONS & ANSWERS
Q. Where did Severe Acute Respiratory Syndrome (SARS) come from?
A. SARS is an infectious disease of the respiratory system characterized by an atypical inflammation of the lungs (pneumonia). Scientists at CDC and other
laboratories have detected a previously unrecognized coronavirus in patients with SARS. This new coronavirus is the leading hypothesis for the cause of SARS,
however, other viruses are still under investigation as potential causes.
Q. What is atypical pneumonia?
A. Pneumonia is an infection of one or both lungs which is usually caused by a
bacteria, virus, or fungus. Atypical pneumonias appear different from 'classic' presentations of this infection and may be more viral in nature. Pneumonia is the sixth leading cause of death in the United States.
Q. What is coronavirus?
A. Coronaviruses are a group of viruses that are a common cause of mild to
moderate upper-respiratory illness in humans. They are associated with respiratory, gastrointestinal, liver and neurologic disease in animals. These viruses have a halo
or crown-like (corona) appearance when viewed under a microscope.
Q. How is SARS transmitted?
A. The disease appears to be primarily spread from person to person through
droplet transmission when in direct close contact with a person with SARS. Direct close contact in this case is defined as having cared for, having lived with, or
having had direct contact with respiratory secretions and body fluids of a person with SARS. For example, when someone sick with SARS coughs or sneezes they
disperse droplets into the air and someone else breathes them in.
It is possible that SARS can be transmitted more broadly through the air or from
objects that have become contaminated. Potential ways in which infections can be transmitted by close contact include touching the skin of other persons or objects
that become contaminated with infectious droplets and then touching your eyes, nose or mouth. This can happen when someone who is sick with SARS coughs or
sneezes droplets onto themselves, other people, or nearby surfaces.
Q. What is the difference between droplet and airborne transmission of viruses?
A. Droplet transmission refers to the spread of viruses contained in relatively large
respiratory droplets that people project when they cough or sneeze. Because of their large size, droplets travel only a short distance (usually 3 feet or less) before
they settle. Droplet transmission can occur either directly when droplets are inhaled by another person, or indirectly when droplets land on an object or surface (such
as a doorknob or telephone) which is then touched by another individual. Common-cold viruses (like rhinovirus) are typically spread by droplets.
Airborne transmission means that the virus is spread by very small respiratory
aerosol (fine mist) particles or dust, which can be breathed in by another person. Small aerosol particles can remain in the air and travel over a greater distance than
larger respiratory droplets. Examples of viruses spread by the airborne route are influenza and measles viruses.
Q. How long do coronaviruses survive in the environment?
A. In general viruses like coronaviruses do not survive a long time in the environment. Scientist are unsure how long this newly discovered coronavirus can
live in the environment; however some preliminary studies by researchers in Hong Kong have indicated both dried and liquid samples of the new coronavirus survived
as long as 24 hours in the environment. Additional studies are under way to examine this important question.
Q. Can SARS be spread from touching contaminated objects or surfaces?
A. It is possible that SARS could be spread when a person touches a contaminated
object or surface; however, how often this might happen, or if it happens at all, is not known at this time. Previously identified coronaviruses (scientists have reported that a new cororavirus may be the cause of SARS) have been shown to survive in
the environment for as long as 3 hours and some preliminary studies by researchers in Hong Kong have indicated both dried and liquid samples of the new coronavirus survived as long as 24 hours in the environment.
To reduce the overall risk for infection by touching contaminated objects and
surfaces, CDC recommends that people wash their hands thoroughly and often with soap and water.
Q. What are the symptoms of SARS?
A. Main symptoms and signs include high fever (>100.4°F/38°C), dry cough, muscle
aches, shortness of breath or breathing difficulties. SARS may be associated with other symptoms, including headache, muscle stiffness, loss of appetite, tiredness (malaise).
Q. What is the incubation period (i.e., time from infection to onset of disease symptoms) for SARS?
A. Usually 2 to 7 days with 3-5 days being more common. Some isolated cases have experienced incubation periods of as long as 10 days.
Q. Is there a test for SARS?
A. No "test" is available yet for SARS. And while coronavirus has not been
definitively proven to be the cause of SARS, CDC, in collaboration with WHO and other laboratories, has developed 2 research tests that appear to be very promising in detecting antibodies to the new coronavirus.
Q. What should I do if I think I have symptoms of SARS?
A. If you are ill with a fever of over 100.4 °F (>38.0°C) that is accompanied by a
cough or difficulty breathing, or that progresses to a cough and/or difficulty breathing, you should consult a health care provider. To help your health care
provider make a diagnosis, tell them about any recent travel to regions where cases of SARS have been reported and whether you were in contact with someone who had these symptoms.
Q. What should I do if I have recently traveled to a country where cases of SARS have been reported?
A. You should monitor your own health for 7 to 10 days following your return. If you
become ill with a fever of over 100.4 °F (>38.0°C) that is accompanied by a cough or difficulty breathing, or that progresses to a cough and/or difficulty breathing,
you should consult a health care provider. To help your health care provider make a diagnosis, tell them about any recent travel to regions where cases of SARS have
been reported and whether you were in contact with someone who had these symptoms.
Q. What has CDC recommended to prevent transmission of SARS in households?
A. CDC has developed interim infection control recommendations for patients with
suspected SARS in the household. The basic precautions include the following:
- Infection control precautions should be continued for SARS patients for 10
days after respiratory symptoms and fever are gone. SARS patients should limit interactions outside the home and should not go to work, school,
out-of-home day care, or other public areas during the 10-day period.
- During this 10-day period, all members of the household with a SARS patient
should carefully follow recommendations for hand hygiene, such as frequent hand washing or the use of alcohol-based hand rubs.
- Each patient with SARS should cover his or her mouth and nose with a tissue
before sneezing or coughing. If possible, a person recovering from SARS should wear a surgical mask during close contact with uninfected persons. If
the patient is unable to wear a surgical mask, other people in the home should wear one when in close contact with the patient.
- Disposable gloves should be considered for any contact with body fluids from
a SARS patient. However, immediately after activities involving contact with body fluids, gloves should be removed and discarded, and hands should be
washed. Gloves should not be washed or reused, and are not intended to replace proper hand hygiene.
- SARS patients should avoid sharing eating utensils, towels, and bedding with
other members of the household, although these items can be used by others after routine cleaning, such as washing or laundering with soap and hot
water. Coronaviruses can survive in the environment for as long as three hours.
- Common household cleaners are sufficient for disinfecting toilets, sinks, and
other surfaces touched by patients with SARS, but the cleaners must be used frequently.
- Other members of the household need not restrict their outside activities
unless they develop symptoms of SARS, such as a fever or respiratory illness.
Q. How should SARS be managed in the workplace?
A. Workers, who in the last 10 days have traveled to a known SARS area, or have
had close contact with a co-worker or family member with suspected or probable SARS could be at increased risk of developing SARS and should be on the alert for
the development of fever (greater than 100.4° F) or respiratory symptoms (e.g., cough or difficulty breathing). If these symptoms develop, do not go to work,
school, or other public areas and seek evaluation by a health-care provider and practice infection control precautions recommended for the home or residential
setting; be sure to contact your health-care provider beforehand to let them know you may have been exposed to SARS.
Q. What is the treatment for SARS?
A. CDC currently recommends that patients with SARS receive the same treatment
that would be used for any patient with serious community-acquired atypical pneumonia of unknown cause. Symptoms should be treated by adequately
protected health professionals. The coronavirus is being tested against various antiviral drugs to see if an effective treatment can be found.
Q. What is the status of the SARS outbreak in the United States?
A. In the United States, cases of SARS continue to be reported primarily among
people who traveled to affected areas; a small number of other people have gotten sick after being in close contact with (that is, having cared for or lived with) a
SARS patient while in the United States. Currently, there is no evidence that SARS is spreading more widely in the community in the United States.
To minimize the risk for SARS among U.S. residents, the public health system is
taking careful and thorough precautions to stop the spread of SARS. People who are suspected of having SARS are being isolated from others and getting care.
People arriving from affected parts of the world (who might have been exposed to SARS) are receiving information about SARS and instructions on what they should
do if they become ill. SARS patients and their contacts are being monitored to help prevent spread of the disease.
Q. How many cases of SARS have occurred in the U.S.?
A. No cases have been confirmed to date in the United States; however, as of April
22, 2003, there were 239 cases, representing 202 suspect cases and 37 probable cases. For information on US cases see:
Q. What is the difference between a "probable" SARS case and a "suspect" SARS case?
A. Suspect SARS cases have fever, respiratory illness, and recent travel to an
affected area with community transmission of SARS and/or contact with a suspect SARS patient. Probable cases meet the criteria for a suspect case and also have
evidence (e.g., chest X-ray) of pneumonia or respiratory failure.
Q Are there any travel restrictions related to SARS?
A. A CDC travel advisory recommends individuals who are planning nonessential or
elective travel to mainland China, Hong Kong, Hanoi, Vietnam, or Singapore consider postponing their trip until further notice. CDC also has issued a travel alert for
Toronto, Canada, to recommend that U.S. travelers to Toronto observe precautions to safeguard their health. For additional information about travel advisories, check www.cdc.gov/travel, which will be updated as necessary. WHO recommends
screening of air passengers departing from a small number of affected areas on flights to another country.
Q. Is there any reason to think SARS is or is not related to bio-terrorism?
A. Information currently available about SARS indicates that people who appear to
be most at risk are either health care workers taking care of sick people or family members or household contacts of those who are infected with SARS. That pattern
of transmission is what would typically be expected in a contagious respiratory or flu-like illness. There is no indication that SARS is linked to bio-terrorism.
This information has been compiled from materials provided by several federal
agencies. For additional information or resource documentation, please reference the websites that follow.
The World Health Organization
Centers for Disease Control and Prevention
State of Rhode Island Department of Health