SARS virus. Artwork of severe acute respiratory syndrome (SARS) virus particles on a world map, illustrating the possibility of a pandemic (worldwide) distribution. SARS is a fatal lung disease that first appeared in China in late 2002, and spread throughout the world through air travel. The disease is caused by the inhalation of virus particles, which are carried in tiny water droplets in the air. The SARS virus is a type of coronavirus. Like all viruses it cannot replicate by itself, instead it infects a cell and uses the machinery of the cell to produce more copies of the virus.