While most coronaviruses cause mild respiratory illness consistent with the common cold, two lethal coronaviruses have been previously identified, including the acute respiratory syndrome coronavirus (SARS-CoV) in 2002 demonstrating 10% mortality and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 producing 37% mortality. In December 2019, a novel coronavirus (2019-nCoV) was isolated from a cluster of patients with pneumonia in Wuhan, China. As reported in the Lancet last week, two thirds of the affected patients in a case series had a history of exposure to the Huanan seafood market.