Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A virus that perhaps created the most alarm in public in the last decade was the SARS coronavirus, the cause of the severe acute respiratory syndrome. Between November 2002 and July 2003, an outbreak of SARS in Hong Kong nearly became a pandemic, with 8,422 cases and 916 deaths worldwide (10.9% fatality) according to the World Health Organization. Within weeks, SARS spread from Hong Kong to infect individuals in 37 countries in early 2003. Though today, the spread of SARS has been fully contained, is not claimed to have been eradicated, as it may still be present in its natural host reservoirs (animal populations) and may potentially return into the human population in the future. Learn more about the severe acute respiratory syndrome, its symptoms and treatment, as well as the virus that causes it in the following pages.