Emerging and re-emerging pathogens are great challenges to the public health (1). A cluster of cases of viral pneumonia of unknown etiology (VPUE), now known as novel coronavirus-infected pneumonia (NCIP), occurred in Wuhan, Hubei Province and was reported to health authorities on December 29, 2019 (2). A national, provincial, and municipal joint investigation team has been assembled to conduct field investigations and implement disease control and prevention measures. This report shows interim results of the investigation and makes recommendations for response measures.