Early in 2003, an outbreak of the until then unknown severe acute respiratory syndrome (SARS) was reported in southeastern People’s Republic of China. The outbreak was thought to have first emerged in the Guangdong province in November 2002. Subsequently, the infections spread to Hong Kong (February 2003) and other countries of Southeast Asia, including Vietnam, Taiwan, and Singapore, as well as to Canada and the United States (http://www.fda.gov/oc/opacom/hottopics/sars/).