On 31 December 2019, a cluster of pneumonia of unknown etiology was reported in Wuhan City, Hubei Province of China. On 9 January Chinese authorities reported in the media that the cause of this viral pneumonia was initially identified as a new type of coronavirus, which is different from any other human coronaviruses discovered so far . Coronaviruses are a large family of respiratory viruses that can cause diseases ranging from the common cold to the Middle-East Respiratory Syndrome and the Severe Acute Respiratory Syndrome (SARS).
The clinical signs and symptoms of the patients reported in this cluster are mainly fever, with a few patients having difficulty in breathing, and chest radiographs showing bilateral lung infiltrates. Some cases were operating dealers or vendors in Huanan Seafood Market. From the currently available information, preliminary investigation suggests that there is no significant human-to-human transmission, and no infections among health care workers have occurred. More information is required to better understand the mode of transmission and clinical manifestation of this new virus. The source of this new virus is not yet known.