Severe acute respiratory syndrome (SARS) is a viral respiratory
illness caused by a coronavirus, called SARS-associated Coronavirus
(SARS-CoV). SARS was first reported in Asia in February 2003. Over the
next few months, the illness spread to more than two dozen countries in
North America, South America, Europe, and Asia before the SARS global
outbreak of 2003 was contained. Apparently civets, maintained in China
as a source of exotic food, are the primary reservoir for the
coronavirus associated with SARS.
The
Coronavirus associated with SARS
Unlike other coronaviruses, which are an important cause of
colds,
SARS-CoV causes infections with a significant morbidity and mortality.
According to the World Health Organization (WHO), a total of 8,098
people worldwide became sick with SARS during the 2003 outbreak. Of
these, 774 died (nearly 10% mortality). In persons over 65 years of
age, the mortality rate approached 50%. Furthermore, about 20% of the
cases occurred in health care workers, which demonstrates the high
infectivity of the virus and its ability to spread in spite of standard
containment and infection control measures which may be enforced.
In general, SARS begins with a high fever (temperature greater than
100.4°F ). Other symptoms may include headache, an overall
feeling of discomfort, and body aches. Some people also have mild
respiratory symptoms at the outset. About 10-20% of
patients have diarrhea. After 2 to 7 days, SARS patients may develop a
dry cough. Most patients develop pneumonia.
The main way that SARS seems to spread is by close person-to-person
contact. The virus is transmitted most
readily by respiratory droplets produced when an
infected person coughs or sneeze and droplets are propelled a
short distance (generally up to 3 feet) through the air and deposited
on the mucous membranes of the mouth, nose, or eyes of persons who are
nearby. The virus also can spread when a person touches a surface or
object contaminated with infectious droplets and then touches his or
her mouth, nose, or eye(s).
Because of its high mortality and ease of spread, SARS-CoV containment
is a critical to its control during an outbreak. Patients with the
disease must
be isolated in negative pressure rooms, and health care providers
must wear respirators when tending to SARS patients or
dealing with SARS-CoV-contaminated materials.
Caring
for a patient with SARS
SARS-CoV infection can be diagnosed by detection of antibody or rise
rise in antibody titer, or by isolation, cultivation and identification
of
the virus, or by use of nucleic acid probes. Rapid identification of
SARS cases, initiation of intantaneous worldwide notification
procedures, and understanding of the biology and genetics of
SARS-CoV,
have so far allowed containment of this emerging disease.
