Much has been learned about SARS since its recognition in southern China in February 2003. The etiologic agent has been identified as a novel coronavirus, new diagnostic tests have been developed, and the viral genome has been sequenced (1). Recently, an almost identical virus, although with 29 extra nucleotides, was isolated from palm civet cats bought in a food market in the city of Shenzhen (2). The civets are nocturnal members of the mongoose family, distantly related to feline cats, and considered a culinary delicacy in southern China. Unconfirmed reports suggest that the virus has also been isolated from several other exotic animals (3). Chinese food handlers, caterers, and chefs were overrepresented fivefold among the virus's first victims, another clue suggesting that SARS is a zoonosis. Having crossed species from animals to people, SARS then spread from person to person.