Severe acute respiratory syndrome (SARS) is a contagious and sometimes fatal respiratory illness. SARS first appeared in China in November 2002. Within a few months, SARS spread worldwide, carried by unsuspecting travelers.
SARS showed how quickly infection can spread in a highly mobile and interconnected world. On the other hand, concerted international cooperation allowed health experts to quickly contain the spread of the disease. There has been no known transmission of SARS anywhere in the world since 2004.