SARS: responding to an unknown virus.
The severe acute respiratory syndrome (SARS) is an emerging infection caused by a novel coronavirus which first appeared in southern China at the end of 2002. In early 2003, through a single incident, it spread to Hong Kong, Singapore, Canada and Vietnam. For busy clinicians in large public hospitals, the response to the virus was initially based on ensuring a high level of protection for staff. However, as the epidemic progressed and more information became available about the virus, procedures were rationalized and the virus is currently under control worldwide. There are, however, numerous unanswered questions concerning super-spreading events, the modes of transmission of the virus and, perhaps most importantly, the rapid detection of the virus early in the course of disease. These issues need to be addressed in case the virus becomes more widespread in the near future.