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
How
many cases of SARS have been reported so far?
Visit WHO's
SARS page for daily updates on case reports in the United States and other
countries. To date, most of the cases have been reported from China.
How
many people have died from SARS?
Visit WHO's
SARS page for a daily update of SARS cases and deaths.
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 (http://www.cdc.gov/ncidod/sars/travel_alert.htm)
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 (http://www.who.int/csr/sars/travel/en/)
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 SAR
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.
CDC
RECOMMENDATIONS
Personal
and Household
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.
CDC
RECOMMENDATIONS
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. Visit http://www.cdc.gov/ncidod/sars/exposureguidance.htm
to read these recommendations.
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.
CDC
RECOMMENDATIONS
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 (available at http://www.cdc.gov/ncidod/sars/airtransport-sarspatients.htm)
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://wwwlink.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.
This information provided by the Centers for Disease Control
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