There is no evidence to suggest that SARS (severe acute
respiratory syndrome) is an airborne virus, the World Health
Organization (WHO) said Monday in a report.
The report, summarizing international research on SARS,
concluded that at all outbreak sites, the main route of
transmission was direct contact, via the eyes, nose and mouth, with
infectious respiratory droplets, the WHO regional office for the
Western Pacific said in a statement.
"The finding that each patient infected on average three others
is consistent with a disease spread by direct contact with
virus-laden droplets rather than with airborne particles," the WHO
said, noting that in airborne diseases such as influenza or
measles, one person can infect an entire room by coughing.
The report, which found health workers at special risk of SARS
and children rarely affected, said health workers accounted for
21percent of all cases. In some cases, transmission occurred even
though they were wearing masks, eye protection, gowns and
gloves.
The report said children were rarely affected, with only two
reported cases of transmission from children to adults and no
reports of transmission from children to other children. No
evidence has been found to show SARS transmission in schools, or in
infants whose mothers were infected during pregnancy.
On the other hand, research found no evidence that patients
transmit the infection 10 days after fever has subsided.
The risk of a person transmitting the disease is greatest at
around day 10 of the illness, when a maximum virus excretion from
the respiratory tract occurs, then declines, the report said.
Research also showed that five international flights were
associated with the transmission of the disease, but found no
evidence of transmission on flights after the March 27 travel
advisory in which the WHO recommended exit screening and other
measures.
The report was released at the start of four consecutive SARS
meetings being hosted in Geneva by the WHO starting Monday through
Nov. 1, which will address priorities for scientific research,
laboratory issues, clinical treatment protocols, and prospects
forvaccine development.
More than 8,000 SARS cases and over 800 deaths in nearly 30
countries were reported between February and July, when the disease
was brought under control. Over 95 percent of these cases occurred
in the Western Pacific Region.
(Xinhua News Agency October 21, 2003)