The emergence of severe acute respiratory syndrome (SARS) in late 2002 and 2003challenged the global public health community to confront a novel epidemic thatspread rapidly from its origins in southern China until it had reached more than 25other countries within a matter of months. In addition to the number of patientsinfected with the SARS virus, the disease had profound economic and political repercussionsin many of the affected regions. Recent reports of isolated new SARS casesand a fear that the disease could reemerge and spread have put public health officialson high alert for any indications of possible new outbreaks. This report examinesthe response to SARS by public health systems in individual countries, the biologyof the SARS coronavirus and related coronaviruses in animals, the economic andpolitical fallout of the SARS epidemic, quarantine law and other public health measuresthat apply to combating infectious diseases, and the role of international organizationsand scientific cooperation in halting the spread of SARS. The report providesan illuminating survey of findings from the epidemic, along with an assessment ofwhat might be needed in order to contain any future outbreaks of SARS or otheremerging infections.