The SARS Outbreak: 100 Days Later
Worst of the SARS Outbreak Is over, But What's Next?
3 Critical Steps in Containing SARS Remain continued...
As officials have learned over and over again, it only takes
one missed case to set off a cascade of new SARS cases or to export the disease
to a new region. According to the WHO, a single, highly infectious person has
been known to set off a chain of transmission that has led to nearly 100
additional SARS infections.
Before an infectious disease can be considered eradicated,
officials at the SARS conference said, three prerequisites must be met:
- An effective way to stop transmission of the infection, ideally a vaccine,
must be developed.
- An easy-to-use diagnostic test must be created to screen for
- Infection of humans must be shown as the only way the virus can survive. If
the virus can live in animals as well, eradication may be much more
Although the virus that causes SARS has been identified and
sequenced genetically, health officials say the development of an effective
vaccine against the SARS virus will take at least a year.
Several diagnostic tests for SARS are currently being
investigated, but none are able to produce fast, accurate results yet.
CDC Director Julie Gerberding, MD, says they have the
technological understanding to create screening tests for the SARS virus, but
the biology of the virus has made knowing when to test for the virus
problematic. For example, some people with SARS do not show evidence of the
SARS virus until they develop pneumonia, while the virus can be seen in others
before they show symptoms, which makes knowing when to take a sample
"Our expectations are so high these days, but the fact that
we have several tests already at this very early stage, just months after
detecting the pathogen, and that we can use them to confirm that people have
this infection is a very optimistic perspective," says Gerberding.
"Ultimately I think we will be successful in developing a bedside
diagnostic test for this coronavirus, and that will be a tremendous help to us
here and also globally."
Harbored in Animals?
Researchers at the conference said too little is known about
the origins of the SARS virus to know for sure if animals play any role in
transmission. Some studies have found traces of the SARS virus in animals sold
at an exotic animal market in Guangdong, where the SARS outbreak originated,
but more studies are needed to confirm these results.
Meanwhile, health officials say the biggest legacy of the SARS
outbreak is a heightened state of alert and awareness of the ever-present
threat of infectious diseases.
"Our level of alertness for emerging infectious diseases,
particularly those of a respiratory nature, needs to become the new normal for
us all," says Gerberding.