Noting that the vast majority of SARS cases thus far reported have occurred in hospitals, the Singapore investigators characterized their study as the first to demonstrate the infection in health care workers with normal chest X-rays. They pointed out that both clinical SARS and milder illness developed in those who were exposed to but not in direct contact with infected patients, suggesting that infection can occur regardless of the intensity of exposure. On the other hand, there was no disease transmission involving health care workers who were in other areas of the hospital. Moreover, no secondary transmission involving the two subjects with mild disease was seen. The investigators cautioned that although mildly symptomatic cases may reflect transmission of low viral loads that are unlikely to spark epidemics, such cases may remain "below the radar" if not actively sought with sensitive assays.

'"/>

Contact: Diana Olson
dolson@idsociety.org
703-299-0201
Infectious Diseases Society of America
2-Feb-2004