Scientists
disagree on
SARS transmission
Last Updated Sat, 14 Jun 2003 13:46:37
ST. JOHN'S - The scientific community is divided over whether
SARS can be transmitted by people without symptoms.
Dick Thompson, spokesman for the World Health Organization, feels the
possibility is remote.
"We haven't seen that anywhere else and we don't know why it would be a
special circumstance in Canada," he said.
Tom Skinner of the U.S. Centers for Disease Control isn't so sure.
Severe acute respiratory syndrome has "only been recognized for a couple of
months and much still needs to be learned about this disease."
The current thinking about
SARS is that transmission requires close contact
with the nose or throat secretions of an infected, symptomatic person.
In Toronto, a Canadian and global SARS hot spot, virtually all transmission
of the disease has taken place in hospitals.
Research has shown the SARS virus can live on surfaces for several days and
can be carried in human feces.
If it turned out that SARS could be transmitted by people without symptoms,
it would be disastrous for control efforts.
However, it's a theoretical problem as doctors can't find out if someone is a
non-symptomatic carrier.
Right now, a SARS diagnose requires three things:
- lab tests on body fluids;
- symptoms (fever, severe headache);
- exposure to a source of infection.
The CDC isn't satisfied with the quality of current lab tests, Skinner said.
"We've got to fine-tune it before the information we gather, especially when
it comes to asymptomatic people, can be beneficial."
Another area of investigation is people who were exposed to the SARS virus
but didn't develop the disease, Skinner said.
