- SARS Basics
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- Origins. The SARS epidemic spread rapidly because people
had little immunity to the newly emerged coronavirus that causes the disease.
Close contact with sick individuals appears to be the primary means of
virus transmission, although research indicates that SARS does not transmit
as easily from person-to-person as more common diseases like the cold or
flu. The disease spread most rapidly among healthcare workers and family
members of infected individuals. Evidence indicates that the virus also
is spread through contact with inanimate objects contaminated with virus-containing
secretions. Recent detection of a related coronavirus in wildcat species
in China raises concerns that SARS may continue to have an animal reservoir,
which would complicate control efforts.
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- Symptoms. SARS can progress rapidly from fever and cough
to serious pneumonia after an average four-to-six-day incubation period,
with up to 20 percent of patients needing mechanical ventilation to survive.
In some patients, progression to pneumonia may be delayed. Death may occur
several weeks to months after initial symptoms.
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- Diagnosis. Accurate, rapid screening diagnostic tests
for SARS are being developed but are not yet licensed in the United States.
During the epidemic healthcare workers generally relied on clinical symptoms
for detection. WHO defines a suspected SARS case as someone with a temperature
over 38 degrees Celsius, a cough or difficulty breathing, and one or more
of the following exposures: close contact with a person who is a suspect
or probable SARS case, or someone who has lived in or visited a region
with SARS transmissions. A "probable case" is a suspected case
with radiographic evidence of pneumonia or positive laboratory tests that
may take days to weeks to complete.
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- Treatment. No proven therapy is available for severe
SARS pneumonia cases. Most clinicians employ respiratory support, antibiotics,
fever reduction, and hydration. Some Chinese doctors have used steroids
and the antiviral drug ribavirin with varying degrees of success.
- Fatalities. Although the overall lethality of SARS is
higher than initially believed, most deaths continue to be among older
patients and those with underlying health problems, such as diabetes or
hepatitis B. The WHO reported in May 2003 that death rates vary substantially
by age:
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- Less than 1 percent in persons 24 years or younger.
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- Up to 6 percent in persons 25 to 44 years old.
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- Up to 15 percent in persons 44 to 64 years old.
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- Greater than 55 percent in persons aged 65 or older.
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- Preliminary reports on nonfatal cases showed SARS patients
required longer hospital stays-an average of three weeks for those under
60 years of age-than patients with other typical respiratory viruses, raising
the economic costs of the SARS outbreak. Moreover, preliminary evidence
suggests that some people who survive SARS could suffer long-term respiratory
damage that increases health complications and costs.
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- <http://www.cia.gov/nic/pubs/other_products/SARS/763959.jpg>
- The World Health Organization: Playing Fairly Well with
a Weak Hand
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- The World Health Organization (WHO) issued an international
health warning on SARS in March 2003 and travel advisories regarding particular
regions hit by the disease. The WHO, in collaboration with the US Centers
for Disease Control and Prevention (CDC) and other organizations, worked
to identify the cause of the disease, assisted local investigators, and
provided guidance on control measures.
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- The SARS experience highlights the bureaucratic and technical
limitations WHO faces in trying to identify and control the international
spread of infectious diseases. Under existing international health regulations,
countries are only required to report to WHO outbreaks of yellow fever,
cholera, and plague. With these diseases, WHO, the United Nations, and
domestic officials have the authority to intervene and prevent the movement
of people and goods to avert cross-border transmission. With other diseases,
WHO plays an advisory role, including issuing travel advisories and offering
advice to member governments on screening procedures. Unless a country
invites in WHO investigators, WHO has a limited ability to respond to outbreaks.
Moreover, WHO has limited capability to investigate suspicious outbreaks
before a country officially reports them.
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- The World Health Assembly, the body that oversees the
WHO, recommended expanding the list of reportable diseases by 2005 to include
notification for public health emergencies of international concern.
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- In 2000, WHO, with assistance from the Canadian Government,
set up the Global Outbreak Alert and Response Network to enhance global
surveillance, detection, and response to emerging infectious diseases.
It uses an electronic collection system to scan worldwide news reports,
websites, discussion groups, and other open source information networks
for rumors or reports of disease outbreaks. These notifications trigger
WHO staff to notify country representatives, who query national authorities
for more information about possible disease outbreaks, bypassing official
government notification channels.
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- Despite these advances, the system may not have picked
up early clues to the SARS outbreak. The electronic monitoring system
currently only searches in English and French, although WHO plans to add
search capabilities in Arabic, Chinese, Russian, and Spanish. In addition,
once WHO receives notification, country cooperation is essential to validate
the outbreak, something Chinese officials avoided until late in the outbreak.
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- Even though checks of passengers at airports were relatively
effective at keeping infected people off airplanes, some lapses did occur.
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- Japan installed infrared thermometers to monitor passengers
at Tokyo's international airport after voluntary testing proved ineffective,
but press reports indicate that the machines cannot keep up with all travelers
at peak times.
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- An Asian man suspected of having SARS boarded a flight
to the United States in May because his flight left before lab results
were received and he had no other symptoms.
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- Quarantines and Isolation.<>2 As SARS spread and
political and economic stakes rose, countries took tougher measures to
contain it. Some countries resorted to strong steps, such as closing schools
despite the low number of cases among children, probably to compensate
for weaknesses in their health-care infrastructure. Open societies seemed
to have trouble enforcing quarantine orders.
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- Some Chinese citizens fled cities and industrial hubs
in response to early government efforts to isolate suspected cases and
quarantine their contacts. Subsequently, Beijing forcibly locked both
patients and healthcare workers in hospitals during the peak of infections,
and the government instituted fines for people violating isolation orders
and employed citizens to keep outsiders out of various villages. Shanghai
officials announced in late May they had quarantined nearly 29,000 people
in the previous two months.
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- Canada threatened those who violated quarantines with
fines or court-ordered isolation after some people defied voluntary measures,
but news reports indicate that some people violated quarantines when the
SARS threat appeared to be fading.
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- Singapore's strict quarantines proved particularly effective
in bringing the disease under control.
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- Sometimes the most effective isolation and quarantine
policies raised concerns about political freedom and human rights. For
example, India and Thailand at one point isolated foreign visitors from
countries that had SARS outbreaks, even though they did not have symptoms
or known exposures.
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- North Korea, which has quarantined entire areas to deal
with epidemics in the past, imposed such tight restrictions for SARS that
it constrained some international aid flows.
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- The World's Quick Response to SARS
- Several factors appeared to facilitate a faster international
reaction to SARS in comparison to other diseases in recent decades.
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- Fear and Uncertainty. The rapid geographic spread of
the mysterious illness created a sense of urgency to respond to a disease
that seemed able to "go anywhere and hit anyone."
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- Stronger Leadership. The World Health Organization took
a more public, activist stance in sounding the alarm and mobilizing the
global response.
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- Scientific Advances. New tools and techniques allowed
researchers better and faster ways to study everything from patterns of
lung damage to the genetic sequence of the coronavirus.
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- Heightened Awareness of BW Threat. Concerns about the
threat posed by biological weapons enhanced the ability and speed of many
countries to identify new infectious diseases.
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- Concern About Missing "Another" AIDS. Some
health officials acknowledge they reacted more quickly to SARS partly due
to fears that the world's slow response in the 1980s to the emergence of
HIV/AIDS allowed the disease to build up devastating momentum.
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- Political Leadership. A key variable in managing the
SARS epidemic was the willingness of political leaders to raise public
awareness of the disease, focus resources, and speed the government response.
As noted above, Vietnamese leaders promptly acknowledged the SARS threat
at an early stage in the outbreak and sought international help. In contrast,
China's political leaders clearly exacerbated the situation by initially
suppressing news of the disease.
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- Reasons to Stay on Guard
- Despite the downturn in cases, SARS has not been eradicated
and remains a significant potential threat. Senior WHO officials and many
other noted medical experts believe it highly likely that SARS will return.
SARS, like other respiratory diseases such as influenza, may have subsided
in the northern hemisphere as summer temperatures rise, only to come back
in the fall.
- Most infectious diseases follow a similar epidemiological
curve, emerging, peaking, and declining over time to a steady state, but
the number of infections, the lethality, and length of time can vary enormously.
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- Even as WHO officials removed the last of its travel
advisories for SARS early this summer, officers repeatedly emphasized the
risk that the disease would be back.
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- Some experts caution that SARS might even lay low for
several years before reappearing, as diseases such as Ebola and Marburg
have done.
- The apparent reservoir of the coronavirus in animals,
Bejing's decision to lift the ban on sales of exotic animals, and lack
of a reliable diagnostic kit, vaccine, or antiviral drug are factors that
preclude eradication.
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- No Reliable Screening Tests. Diagnosis remains almost
as much an art as a science as long as no proven screening test has been
developed. Diagnostic kits currently under development can catch only
about 70 percent of SARS cases, and their utility for widespread deployment
is not yet known. SARS is difficult to detect, particularly in the early
stages, even for countries with the most modern medical capabilities, raising
the risk that healthcare workers will miss mild cases. Moreover, there
is little prospect of a vaccine in the short-term.
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- Various countries have different definitions of suspected
and probable cases and have changed the definitions over time.
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- SARS Could Mutate. Natural mutations in the coronavirus
which causes SARS could alter basic characteristics of the disease, but
whether a mutation would make SARS more or less dangerous is impossible
to predict. A significant increase in the transmissibility or lethality
of SARS obviously would pose greater health risks and raise fears around
the globe.
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- Mutations could be particularly problematic if they alter
the symptoms associated with SARS, making it harder to identify suspected
cases.
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- Researchers are studying a group of Canadians who tested
positive for the SARS virus last spring but never got sick in order to
see if they still might have infected others.
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- Mutations also would complicate the development of a
treatment or vaccine, which already probably is several years away.
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- Difficult to Maintain Vigilance. The willingness of
healthcare workers to serve in the face of significant infection risks
has been a key variable in the battle against SARS and other emerging diseases.
Most healthcare workers in countries hit by SARS toiled long hours under
dangerous conditions. The rate of infection among hospital workers was
much higher than among the general public, underscoring the difficulty
even professionals had in maintaining stringent infection control procedures.
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- At one point 20 percent of those infected in Hong Kong
were nurses, and over 300 healthcare workers were infected within a 17-day
period in China during April.
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- Some health workers refused to work in SARS wards. This
problem is likely to grow in both rich and poor countries if the disease
resurges.
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- In Taiwan, where over 90 percent of SARS infections occurred
in hospitals, over 160 health workers quit or refused to work on SARS wards.
The government threatened to revoke their professional licenses.
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- The Chinese government fired at least six doctors who
refused to treat SARS patients and barred them from practicing for life.
China also tried to encourage healthcare workers by launching public relations
campaigns hailing the work of the Angels in White, and Beijing offered
bonus pay and staffed SARS hospitals with Army medical staff.
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- Press reports in Canada indicate that some nurses refused
to work in SARS wards in Toronto despite a doubling of their wages and
lobbied for an official government inquiry on the handling of the epidemic.
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- Shortages in trained healthcare personnel were exacerbated
when many healthcare workers fell ill to SARS and were replaced by workers
with less training.
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- Taiwan appeared so eager to declare victory over SARS
that it relaxed its standards before the disease was brought under control.
Press reports suggest that some healthcare workers were so fatigued from
the crisis that they cut corners.
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- Canadian officials acknowledge that the second outbreak
in Toronto resulted from hospitals relaxing infection control regimes too
quickly.
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- For The Complete Report See: National Intelligence Council
report on SARS
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- <>http://www.cia.gov.nic/pubs/other_products/SAR/ICA03_09.htm
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- Astraea Kelly
- <mailto:wingsong@earthlink.net>wingsong@earthlink.net
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