Cluster of pneumonia cases caused by a novel coronavirus, Wuhan, China, 2020

Summary:

A novel coronavirus (2019-nCoV) has been isolated and considered the causative agent of the cluster of 41 pneumonia cases in the area of Wuhan, Hubei province in China, and three travel-related cases in Thailand and Japan, arriving from Wuhan. As of 16 January 2020, there is no clear indication of sustained human-to-human transmission. The report of two small family clusters in Wuhan and the exposure history of the imported Japanese case (history of contact with a person with an acute, not laboratory confirmed, respiratory infection in Wuhan) suggest that person-to-person transmission may have occurred. In the absence of detailed information from the ongoing studies in China, it is impossible to quantify the potential of the 2019-nCoV for human-to-human transmission.

The majority of detected pneumonia cases reported having visited the Wuhan Huanan Seafood Wholesale Market recently before disease onset. Some cases did not report any exposure to this specific market, but to other food markets in Wuhan. For a few cases there was no direct connection with a food market. The occurrence of a few cases having no history of contact with the implicated market or other any similar market suggests the possibility of the infection source being even more widely distributed.

The likelihood of importation of cases of novel coronavirus (2019-nCoV) to the European Union (EU) is considered to be low, but cannot be excluded in the current situation. This document presents disease background, risk assessment and options for response.

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