ities. RESULTS Some of the epidemiological characteristics of 2019-nCoV have been identified. However, there remain considerable uncertainties, which should be considered when providing guidance to public health authorities on control measures. CONCLUSIONS Additional studies incorporating more detailed information from confirmed cases would be valuable. INTRODUCTION Several clusters of patients with pneumonia of unknown etiology in Wuhan, Hubei Province, China were reported to the Chinese health authorities starting on December 8, 2019, and most of these cases were epidemiologically linked to a local fish and animal market [1,2]. The pathogenic agent responsible for these clusters of pneumonia was identified as a 2019 novel coronavirus (2019-nCoV) [1]. At the very beginning of the 2019-nCoV outbreak in China, much remained unknown, except for the fact that it was transmitted by direct exposure at the market [3]. However, person-to-person transmission of 2019-nCoV has been confirmed [4], and asymptomatic individuals have been identified as potential sources of infection [5]. The numb