Severe Acute Respiratory Syndrome (SARS) is a respiratory illness belonging to a common class of viruses called coronaviruses. SARS was first reported in Asia in February 2003 and spread quickly to two dozen countries before being contained successfully. There have been no outbreaks since 2004. Symptoms usually begin with a high fever, and may include a headache, an overall feeling of discomfort, and body aches. Some people have mild respiratory symptoms at the outset, and 10-20% experience diarrhea. After 2-7 days, SARS patients may develop a dry cough. Most will develop pneumonia as a secondary infection. SARS is most easily spread by respiratory droplets released when an infected individual coughs or sneezes.