Figure 3.

Severe Acute Respiratory Syndrome (SARS) was caused by a coronavirus thought to have spilled over from bats to palm civets then on to humans as a result of trading wild and farmed species at markets, which achieved pandemic spread (including outbreaks in China, Singapore, Taiwan and Toronto, among others) in 2002 and 2003. Pale arrows depict interspecific (spillover) transmission; dark arrows show amplification by intraspecific transmission (including transmission between humans). Genome sequence analyses of the virus suggest it adapted rapidly to each of its novel hosts; sequences from early human cases showed strong homology to virus from civets and bats, but sequences from later cases had diverged (reviewed in Wang & Eaton 2007). Adapted from Hatcher & Dunn (2011).