Abstract
Severe acute respiratory syndrome (SARS) was diagnosed in more than 1800 patients in 17 countries (including the United States and Canada) between February 1 and March 31, 2003. During this two-month period, the World Health Organization (WHO) coordinated an international investigation that has produced unprecedented scientific and epidemiologic discoveries with unprecedented speed. On March 12, the WHO issued a global alert about SARS. On March 14, the Centers for Disease Control and Prevention (CDC) activated its emergency operations center to support the response of the WHO to this global threat. Within 24 hours of the official invitations, CDC investigators joined WHO field teams in several affected Asian countries, supported by the full complement of laboratory, epidemiologic, communications, and logistic capabilities of the CDC and the Department of Health and Human Services (DHHS).