Wresting SARS from Uncertainty

Carlo Urbani, a World Health Organization (WHO) epidemiologist stationed in Vietnam, alerted the global health community to the high transmissibility and lethality associated with an apparently new respiratory disease. This disease, now called severe acute respiratory syndrome (SARS), is believed to have emerged in China in November 2002 and progressed to a global health threat by the spring of 2003 (1-3). On March 15, 2003, with clusters of SARS cases being reported from China, Hong Kong, Vietnam, Singapore, and Canada, WHO issued a global travel alert. At that point, the international health community faced a potential pandemic for which there were no identified causal agent, no diagnostic laboratory assays, no defined properties or risk factors for transmission, no infection-control practices of proven efficacy, and no known treatment or prevention measures. Given that setting, the declaration on July 5 that SARS had been contained (in less than 4 months after its initial recognition), represented a remarkable achievement for a truly extraordinary international public health effort.