2,353 worldwide

  84 deaths

 SOURCE: World Health Organization, April 4, 2003.

April 1, 2003 -- Severe acute respiratory syndrome (SARS) is spread when someone sick with SARS coughs or sneezes 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.

To control the spread of the disease among close contacts and healthcare workers of recovering SARS patients, the CDC recommends the following safety precautions for at least 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 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 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 people. If the patient is unable to wear a surgical mask, others in the home should wear masks 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 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.
  
   
• Other members of the household need not restrict their outside activities unless they develop symptoms of SARS such as a fever or respiratory illness.
  
   
• A CDC travel advisory recommends that people who are planning nonessential travel to mainland China, Hong Kong, Hanoi, Vietnam, or Singapore postpone their trip until further notice.

SOURCE: CDC.

If you have plans to travel internationally and are concerned about SARS, the CDC provides the following advice.

Before you travel

• Don't go to mainland China, Hong Kong, Singapore, and Hanoi, unless you really have to. You can still go to Canada. SARS doesn't seem to spread there right now.
• Be sure you are current on all your shots. See your health care provider at least 4 to 6 weeks before travel to get the latest shots and facts you need.
• Check your health insurance. You may want to get more coverage for medical evacuation in case you get sick abroad.
• Ask the U.S. Department of State (DOS) about health care services in the country where you're going. DOS has a list of foreign health care providers and health care facilities at www.travel.state.gov/acs.html#medical.

If you get sick while traveling in an area affected by SARS

• See a health care provider and say that you're worried about being exposed to SARS.
• Don't travel while sick. Limit your contact with others as much as you can to help prevent the spread of any contagious disease you may have.
• If you don't know of any provider in the foreign country, call the U.S. embassy or consulate to get the name of a provider.
• As with all contagious diseases, the best way to not get sick is to wash your hands often with soap and water. If you don't have soap and water, use alcohol-based hand rubs.

When you come back home from areas affected by SARS

• If you were sick on your trip or return home sick, see your health care provider right away. Mention your symptoms and the countries you visited. You may be asked to fill out a form about your disease and give your name and address to public health authorities.
• If you leave an area affected by SARS, a screener may ask you about your health before you board the plane.
• If you come back from areas affected by SARS, you will get a travel alert card when you land. If you're not sick and didn't get sick abroad but may have been in touch with someone with SARS, check your health for the next 10 days.

Published April 4, 2003.

Medically reviewed by Michael W. Smith, MD.

See where SARS cases have been reported and find out how to protect yourself.

A New Disease Called SARS

The Centers for Disease Control and Prevention (CDC) is investigating a new disease called severe acute respiratory syndrome (SARS). The disease was first reported among people in Guangdong Province (China), Hanoi (Vietnam), and Hong Kong. It has since spread to other countries. As of April 1, more than 70 cases of SARS had been reported in the United States. This fact sheet describes the disease and important guidelines for preventing the spread of SARS.

Symptoms of SARS

In general, SARS begins with a fever greater than 100.4°F [>38.0°C]. Other symptoms may include headache, an overall feeling of discomfort, and body aches. Some people also experience mild respiratory symptoms. After 2 to 7 days, SARS patients may develop a dry cough and have trouble breathing.

How SARS Spreads

Public health experts think that SARS is spread by close contact between people. SARS is most likely spread when someone sick with the disease coughs droplets into the air and someone else breathes them in. It is possible that SARS also can spread more broadly through the air or from touching objects that have become contaminated.

Who Is at Risk For SARS

Cases of SARS continue to be reported mainly among people who have had direct close contact with an infected person, such as those sharing a household with a SARS patient and health care workers who did not use infection control procedures while taking care of a SARS patient. In the United States, there is no indication of community spread at this time. CDC continues to monitor this situation very closely.

What You Should Do to Protect Yourself

CDC has issued interim guidelines for patients with suspected SARS in the healthcare setting and in households. These guidelines may change as we learn more about SARS. If you get sick with the symptoms described above and have been in close contact with someone who might have SARS, see your health care provider and follow the guidelines below.

Guidelines

If you think you (or someone in your family) might have SARS, you should:

• Consult a health care provider as soon as possible.
• Cover your mouth and nose with tissue when coughing or sneezing. If you have a surgical mask, wear it during close contact with other people. A mask can reduce the number of droplets coughed into the air.

If you have SARS and are being cared for at home, you should:

• Follow the instructions given by your health care provider.
• Limit your activities outside the home during this 10-day period. For example, do not go to work, school, or public areas.
• Wash your hands often and well, especially after you have blown your nose.
• Cover your mouth and nose with tissue when you sneeze or cough.
• If possible, wear a surgical mask when around other people in your home. If you can't wear a mask, the members of your household should wear one when they are around you.
• Don't share silverware, towels, or bedding with anyone in your home until these items have been washed with soap and hot water.
• Clean surfaces (counter or tabletops, door knobs, bathroom fixtures, etc.) that have been contaminated by body fluids (sweat, saliva, mucous, or even vomit or urine) from the SARS patient with a household disinfectant used according to the manufacturer's instructions. Wear disposable gloves during all cleaning activities. Throw these out when you are done. Do not reuse them.
• Follow these instructions for 10 days after your fever and respiratory symptoms have gone away.

If you are caring for someone at home who has SARS, you should:

• Be sure that the person with SARS has seen a health care provider and is following instructions for medication and care.
• Be sure that all members of your household are washing their hands frequently with soap and hot water or using alcohol-based hand wash.
• Wear disposable gloves if you have direct contact with body fluids of a SARS patient. However, the wearing of gloves is not a substitute for good hand hygiene. After contact with body fluids of a SARS patient, remove the gloves, throw them out, and wash your hands. Do not wash or reuse the gloves.
• Encourage the person with SARS to cover their mouth and nose with a tissue when coughing or sneezing. If possible, the person with SARS should wear a surgical mask during close contact with other people in the home. If the person with SARS cannot wear a surgical mask, other members of the household should wear one when in the room with that person.
• Do not use silverware, towels, bedding, clothing, or other items that have been used by the person with SARS until these items have been washed with soap and hot water.
• Clean surfaces (counter or tabletops, door knobs, bathroom fixtures, etc.) that have been contaminated by body fluids (sweat, saliva, mucous, or even vomit or urine) with a household disinfectant used according to the manufacturer's instructions. Wear disposable gloves during all cleaning activities. Throw these out when done. Do not reuse them.
• Follow these instructions for 10 days after the sick person's fever and respiratory symptoms have gone away.
• If you develop a fever or respiratory symptoms, contact your health care provider immediately and tell him or her that you have had close contact with a SARS patient.

For more information, call the CDC public response hotline at (888) 246-2675 (English), (888) 246-2857 (Español), or (866) 874-2646 (TTY)

Published April 2, 2003.
Medically reviewed by Michael W. Smith, MD.

March 20, 2003 -- As word of a mysterious pneumonia spreads across the globe, healthcare providers are seeing growing numbers of "worried well" in their emergency rooms and offices who fear they may have contracted SARS (severe acute respiratory syndrome).

Officials say symptoms like cough, difficulty breathing, and fever are very common during the current cold and flu season. But it's extremely unlikely that you have SARS unless you have recently traveled to Southeast Asia or had close, personal contact with someone who has.

Until a cause is identified, the World Health Organization broadly defines a case of severe acute respiratory syndrome as someone with:

• A fever of greater than 100.4 degrees
• One or more of the following respiratory symptoms: cough, shortness of breath or difficulty breathing
• And either close contact with a known SARS case or a history of travel to one of the affected areas within the last 10 days before the emergence of symptoms.

Officials urge anyone who develops these pneumonia symptoms after recent travel or contact with affected individuals to contact a healthcare provider and provide complete details of this travel and type of contact.

If your healthcare provider believes you might have been exposed to severe acute respiratory syndrome, he or she will conduct further tests to eliminate other potential causes for the illness. And until more is known about the cause of this mysterious pneumonia, officials recommend that doctors treat SARS as they would treat any form of unknown pneumonia.

Following the recommendations of the CDC and WHO, people thought to have SARS should be hospitalized and isolated from other patients, according to standard infectious disease treatment guidelines.

SOURCE: World Health Organization, CDC.

See where SARS cases have been reported and find out how to protect yourself.

What is SARS?

SARS is a respiratory illness that has recently been reported in Asia, North America, and Europe. For additional information, check the World Health Organization's (WHO) SARS Web site or visit other pages on CDC's SARS Web site.

What are the symptoms and signs of Severe Acute Respiratory Syndrome (SARS)?

The illness usually begins with a fever (measured temperature greater than 100.4°F [>38.0°C]). The fever is sometimes associated with chills or other symptoms, including headache, general feeling of discomfort, and body aches. Some people also experience mild respiratory symptoms at the outset.

After 2 to 7 days, SARS patients may develop a dry, nonproductive cough that might be accompanied by or progress to the point where insufficient oxygen is getting to the blood. In 10% to 20% of cases, patients will require mechanical ventilation.

If I were exposed to SARS, how long would it take for me to become sick?

The incubation period for SARS is typically 2-7 days; however, isolated reports have suggested an incubation period as long as 10 days. The illness usually begins with a fever (>100.4°F [>38.0°C]) (see signs and symptoms, above).

What medical treatment is recommended for patients with SARS?

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. Several treatment regimens have been used for patients with SARS, but there is insufficient information at this time to determine if they have had a beneficial effect. Reported therapeutic regimens have included antibiotics to presumptively treat known bacterial agents of atypical pneumonia. Therapy also has included antiviral agents such as oseltamivir or ribavirin. Steroids also have been administered orally or intravenously to patients in combination with ribavirin and other antimicrobials.

Spread of SARS

How is SARS spread?

The principal way SARS appears to be spread is through droplet transmission; namely, when someone sick with SARS coughs or sneezes 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.

How long is a person with SARS infectious to others?

Information to date suggests that people are most likely to be infectious when they have symptoms, such as fever or cough. However, it is not known how long before or after their symptoms begin that patients with SARS might be able to transmit the disease to others.

Who is most at risk of contracting SARS?

Cases of SARS continue to be reported primarily among people who have had direct close contact with an infected person, such as those sharing a household with a SARS patient and health care workers who did not use infection control procedures while caring for a SARS patient. In the United States, there is no indication of community transmission at this time. CDC continues to monitor this situation very closely.

Cause of SARS

What is the cause of SARS?

Scientists at CDC and other laboratories have detected a previously unrecognized coronavirus in patients with SARS. While the new coronavirus is still the leading hypothesis for the cause of SARS, other viruses are still under investigation as potential causes.

What are coronaviruses?

Coronaviruses are a group of viruses that have a halo or crown-like (corona) appearance when viewed under a microscope. These viruses are a common cause of mild to moderate upper-respiratory illness in humans and are associated with respiratory, gastrointestinal, liver and neurologic disease in animals. Coronaviruses can survive in the environment for as long as three hours.

What evidence is there to suggest that coronaviruses may be linked with SARS?

CDC scientists were able to isolate a virus from the tissues of two patients who had SARS and then used several laboratory methods to characterize the agent. Examination by electron microscopy revealed that the virus had the distinctive shape and appearance of coronaviruses. Tests of serum specimens from patients with SARS showed that the patients appeared to have recently been infected with this coronavirus. Other tests demonstrated that coronavirus was present in a variety of clinical specimens from patients, including nose and throat swabs. In addition, genetic analysis suggests that this new virus belongs to the family of coronaviruses but differs from previously identified coronaviruses. These laboratory results do not provide conclusive evidence that the new coronavirus is the cause of SARS. Additional specimens are being tested to learn more about this coronavirus and its link with SARS.

If coronaviruses usually cause mild illness in humans, how could this new coronavirus be responsible for a potentially life-threatening disease such as SARS?

There is not enough information about the new virus to determine the full range of illness that it might cause. Coronaviruses have occasionally been linked to pneumonia in humans, especially people with weakened immune systems. The viruses can also cause severe disease in animals, including cats, dogs, pigs, mice, and birds.

Has new information about coronavirus changed the recommendations for medical treatment for patients with SARS?

The possibility that coronavirus is the cause of SARS has not changed treatment recommendations. The new coronavirus is being tested against various antiviral drugs to see if an effective treatment can be found.

Is there a test for SARS?

No "test" is available yet for SARS; however, 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. CDC is working to refine and share this testing capability as soon as possible with laboratories across the United States and internationally.

What about reports from other laboratories suggesting that the cause of SARS may be a paramyxovirus?

Researchers from several laboratories participating in the WHO network have reported the identification of a paramyxovirus in clinical specimens from SARS patients. These laboratories are still investigating the possibility that a paramyxovirus is a cause of SARS.

The Outbreak

What is CDC doing to combat this health threat?

CDC is working closely with WHO and other partners as part of a global collaboration to address the SARS outbreak. For its part in this international effort, CDC has taken the following actions:

• Activated its Emergency Operations Center to provide round-the-clock coordination and response.
  
   
• Committed more than 160 infectious disease experts and support staff to work on the SARS response.
  
   
• Deployed medical officers, epidemiologists, and other specialists to assist with on-site investigations around the world.
  
   
• Provided ongoing assistance to state and local health departments in investigating possible cases of SARS in the United States.
  
   
• Issued multiple notices providing guidance on ways to minimize the risk for SARS in health care facilities, in the household, when traveling, and in other settings.
  
   
• Conducted extensive laboratory testing of clinical specimens from SARS patients to identify the cause of the disease.
  
   
• Initiated a system for distributing health alert notices to travelers who may have been exposed to cases of SARS.

As always, CDC is committed to communicating regularly and effectively with public health professionals, elected leaders, clinicians, and the general public.

Travel and Quarantine

What are CDC's quarantine officials doing to prevent and control the spread of SARS?

CDC's quarantine inspectors or their designees are distributing health alert cards to air passengers returning in airplanes either directly or indirectly to the United States from China, Singapore, and Vietnam. The notices ask travelers to monitor their health for 10 days and to see a doctor if they get a fever with a cough or have difficulty breathing. CDC distributes approximately 15,000 health alert notices each day to air travelers returning from the affected regions at 23 ports of entry. Inspectors also are boarding airplanes if a traveler has been reported with symptoms matching the case definition of SARS.

The World Health Organization (WHO) has recommended procedures for pre-departure screening of airline passengers from some countries for respiratory illnesses or other symptoms of SARS.

What information about SARS is being provided to people traveling on ships?

SARS information contained on CDC's health alert cards is being provided by the major shipping associations and the International Council of Cruise Lines to people traveling on cargo ships and cruise ships at U.S. ports. Inspectors also are boarding ships if a passenger or crew member has been reported with symptoms matching the case definition of SARS.

What does a quarantine inspector do?

Quarantine inspectors serve as important guardians of health at borders and ports of entry into the United States. They routinely respond to illness in arriving passengers and ensure that the appropriate medical action is taken.

What is considered routine health inspections of airplanes or ships versus what is happening now?

Routine health inspections consist of working with airline, cargo ship, and cruise ship companies to protect passengers and crew from certain infectious diseases. Quarantine inspectors meet arriving aircraft and ships reporting ill passengers and/or crew (as defined in the foreign quarantine regulations [pdf]) and assist them in getting appropriate medical treatment.

What is the risk to individuals who may have shared a plane or boat trip with a suspected SARS patient?

Cases of SARS continue to be reported primarily among persons who have had direct close contact with an infected person, such as those sharing a household with a SARS patient and health care workers who did not use infection control procedures while attending to a SARS patient. SARS has also occurred among air travelers, primarily travelers to and from Hong Kong, Hanoi, Singapore, and mainland China.

CDC is requesting locating information from travelers who are on flights with people suspected of having SARS. CDC, with the help of state and local health authorities, is attempting to follow-up with these travelers for 14 days to make sure no one develops symptoms consistent with SARS.

Who actually notifies quarantine officials of potential SARS cases? Is it the crew of the airplane or ship? The passengers?

Under foreign quarantine regulations, the master of a ship or captain of an airplane coming into the United States from a foreign port is required by law to report certain illnesses among passengers. The illness must be reported to the nearest quarantine official. If possible, the crew of the airplane or ship will try to relocate the ill passenger or crew member away from others. If the passenger is only passing through a port of entry on his/her way to another destination, port health authorities may refer the passenger to a local health authority for assessment and care.

If I'm on board an airplane or ship with someone suspected of having SARS, will I be allowed to continue to my destination?

CDC does not currently recommend that the onward travel of healthy passengers be restricted in the event that a passenger or crew member suspected of having SARS is removed from the ship or airplane by port health authorities. All passengers and crew members may be advised by port health authorities to seek medical attention if they develop SARS symptoms.

What does a quarantine official do if a passenger is identified as meeting the case definition for suspected SARS?

Quarantine officials arrange for appropriate medical assistance to be available when the airplane lands or the ship docks, including medical isolation. Isolation is important not only for the sick passenger's comfort and care but also for the protection of members of the public. Isolation is recommended for travelers with suspected cases of SARS until appropriate medical treatment can be provided or until they are no longer infectious.

What does a quarantine official do if a passenger identified as meeting the case definition for suspected SARS refuses to be isolated?

Many levels of government (Federal, State, and local) have basic authority to compel isolation of sick persons to protect the public. In the event that it is necessary to compel isolation of a sick passenger, CDC will work with appropriate State and local officials to ensure that the passenger does not infect others.

Other

Is there any reason to think SARS is or is not related to terrorism?

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.

Personal and Household Recommendations

What should I do if I think I have SARS?

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 him or her 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.

What has CDC recommended to prevent transmission of SARS in households?

CDC has developed interim infection control recommendations available at http://www.cdc.gov/ncidod/sars/ic-closecontacts.htm for patients with suspected SARS in the household. The basic precautions outlined in this document 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.
  
   
• 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.

Healthcare Settings

What has CDC recommended to prevent transmission of SARS in the health care setting?
Transmission of SARS to health care workers appears to have occurred after close contact with symptomatic individuals before recommended appropriate infection control precautions were implemented. CDC has developed interim infection control recommendations for the management of exposures to SARS in the health care and other institutional settings.

Health care facilities should be vigilant in conducting active surveillance for fever or respiratory symptoms among care givers with unprotected exposure to SARS patients. Health care workers who develop fever or respiratory symptoms during the 10 days following an unprotected exposure to a SARS patient should not report for duty. Such workers should stay home and report symptoms to the appropriate facility point of contact (e.g., infection control or occupational health) immediately. Exclusion from duty should be continued for 10 days after the resolution of fever and respiratory symptoms. During this period, infected workers should avoid contact with people both in the facility and in the community.

Exclusion from duty is not recommended for an exposed health care worker if they do not have fever or respiratory symptoms; however, the worker should report any unprotected exposure to SARS patients to the appropriate facility point of contact immediately.

What precautions should health care facilities follow regarding visits by close contacts of SARS patients?

Close contacts (e.g., family members or other members of the household) of SARS patients are at risk for infection. Health care facilities should implement a system to screen for fever or respiratory symptoms among such contacts who visit the facility. Close contacts with fever or respiratory symptoms should not be allowed to enter the health care facility as visitors and should be educated about this policy. Health care facilities should educate all visitors about use of infection control precautions (www.cdc.gov/ncidod/sars/infectioncontrol.htm) when visiting SARS patients and should emphasize the importance of following these precautions.

Travel and Quarantine

Are there any travel restrictions related to SARS?

At this time there are no travel restrictions in place that are directly related to SARS. However, a CDC travel advisory recommends that individuals who are planning nonessential or elective travel to mainland China, Hong Kong, Hanoi, Vietnam, or Singapore may wish to postpone their trip until further notice. For additional information about travel advisories, check CDC's Travelers' Health site, which will be updated as necessary.

What should I do if I have recently traveled to a country where cases of SARS have been reported?

You should monitor your own health for 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 him or her 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.

CDC has recommended guidelines for medical aircraft that transport SARS patients. Should commercial airlines also follow these guidelines?

No. This guidance is intended specifically for air medical transport (AMT) service providers that use specialized aircraft to transport SARS patients. It should not be generalized to commercial passenger aircraft. These interim recommendations for AMT are based on standard infection control practices, AMT standards, and epidemiologic information from ongoing investigations of SARS, including experience from transport of 2 patients during this outbreak. Specific guidelines for airline crew and flight personnel of commercial aircrafts are available at http://www.cdc.gov/ncidod/sars/flight_crew_guidelines.htm. CDC also has developed interim guidance for cleaning of commercial passenger aircraft after a flight with a suspected SARS passenger http://www.cdc.gov/ncidod/sars/aircraftcleanup.htm.

Published April 1, 2003.

Medically reviewed by Michael W. Smith, MD.

Officials Say SARS is 'Fire Drill' for Bioterrorism, Disease Epidemics

April 4, 2003 -- International and local efforts to contain the spread of the mysterious illness known as SARS (severe acute respiratory syndrome) reached a new level of urgency today as President Bush authorized the quarantine of SARS patients in the U.S. The move comes as the number of suspected SARS cases in the U.S. rose to 115 today, spread across 29 states.

Internationally, the number of people with SARS rose to more than 2,350 today, including more than 80 deaths. No deaths due to SARS have been reported in the U.S.

Bush's executive order authorizes the Health and Human Services Secretary to determine when quarantine is necessary to control the spread of SARS as well as other infectious diseases.

According to the CDC, a quarantine order applies to people who have been exposed and may be infected with a disease but are not yet ill. By identifying exposed persons and restricting their movements, officials say quarantine is a medically effective way to protect the public from disease.

The move will likely help CDC curb the influx of SARS into the U.S. among people who may have been exposed but have not yet developed symptoms. Symptoms of SARS, including fever, headache, cough, and shortness of breath, usually develop within two to seven days after exposure, but some cases have been reported in as little as 24 hours or as long as 10 days after exposure to SARS.

But international travel makes controlling SARS particularly troublesome. "The speed at which people can move is faster than the incubation period of the disease," says Marty Citron, MD, deputy director of global quarantine and isolation at the CDC. "The incubation period for SARS is a matter of days and the time it takes to circumnavigate the globe is a matter of hours."

Since the first mysterious pneumonia cases were reported in the Guangdong province of southern China in November, the disease now known as SARS has now spread to four continents. The first SARS case in South America was reported yesterday in Brazil. The majority of cases have been concentrated in China, Hong Kong, Singapore, Vietnam, and Canada.

China also apologized today for not doing a better job of informing the public and international health organizations about the SARS epidemic and pledged full cooperation with the World Health Organization's team currently investigating the outbreak in Guangdong. In addition, China's Ministry of Health finally began to release daily reports on the number of SARS cases and related deaths. As of April 2, China has reported 1,220 SARS cases and 49 deaths.

The WHO and CDC also took part in an unprecedented worldwide broadcast about preventing the spread of SARS to help educate healthcare providers about the newly emerging disease.

Overall, officials say about 4% of SARS patients have died as a result of the disease, and the majority of these people have been over 40 years old and had other illnesses.

"This is not easy, and we do not have all the answers," says Linda Chiarello, RN, MS, of the CDC. Chiarello recently returned from studying the outbreak in Asia and briefed the participants on strategies to prevent the spread of SARS in hospitals and at home.

The disease is believed to be spread through close contact with an infected person through contact with droplets released from sneezes or coughs. But the possibility of airborne transmission of SARS has not been ruled out.

Of the 115 suspected SARS cases in the U.S., 109 are in people who were exposed to SARS during recent travels to the affected areas in Asia. The remaining six cases include two healthcare workers who cared for an infected patient and four people who were family members or close contacts of SARS patients.

CDC officials say those facts show that SARS does not yet pose a threat to the general public in the U.S.

"If you haven't traveled to an affected area or been exposed to an ill family member or patient, there's no evidence that you're at risk at all," says James Hughes, MD, director of CDC National Center for Infectious Diseases.

But Hughes says it's always important to practice good hygiene, such as frequent hand washing, to reduce your risk of becoming sick from an infectious disease at any time.

The CDC has also published specific guidelines on reducing the risk of infection for people who have close contact with SARS patients. See how to protect yourself from SARS for more information on these recommendations.

Since the global outbreak began three weeks ago, health officials have been able to contain the spread of the disease in all but two areas, Hong Kong and the adjoining Guangdong province in southern China.

Earlier this week, WHO issued a travel warning advising people to postpone non-essential travel to Hong Kong and Guangdong due to the rapid spread and unusual nature of the SARS outbreak in these areas.

WHO has also requested that all passengers departing from all affected areas in Asia be screened for symptoms of SARS, such as fever and respiratory symptoms, before getting on outbound international flights.

The CDC is also continuing to meet arriving planes and ships from the affected areas and providing passengers with health alert notices to warn them that they may have been exposed to SARS and advise them to watch for symptoms. Since the CDC enacted this policy on March 17, officials have met more than 1,000 flights and distributed more than 250,000 health alert notices.

SOURCES: World Health Organization broadcast "Preventing the Spread of Severe Acute Respiratory Syndrome (SARS)," April 4, 2003. CDC telebriefing, April 4, 2003, News release, World Health Organization.