What caused SARS? Severe acute respiratory syndrome (SARS) is a serious form of pneumonia. It is caused by a virus that was first identified in 2003. Infection with the SARS virus causes acute respiratory distress (severe breathing difficulty) and sometimes death. Severe acute respiratory syndrome (SARS) is a rapidly spreading, potentially fatal infectious viral disease. According to the Centers for Disease Control and Prevention (CDC), SARS was recognized as a global threat in March 2003. The viral disease first appeared in Southern China in November 2002 and spread to more than 24 countries in Asia, Europe, North America, and South America. There have not been any new cases of SARS since 2004, and the risk is relatively low. Although they were dealing with a newly-discovered virus that behaved differently than other known viruses, world health officials were able to contain the SARS epidemic within a few short months. For another SARS outbreak to emerge, the SARS virus would need to be transmitted from an animal source, a lab accident, or humans who have not been rapidly diagnosed, isolated, and treated. China has reported a few cases of SARS since December 2003. Chinese healthcare professionals have heightened awareness of symptoms and are prepared to use proper infection control measures to prevent another outbreak.