[The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China].

An outbreak of 2019 novel coronavirus diseases (COVID-19) in Wuhan, China has spread quickly nationwide. Here, we report results of a descriptive, exploratory analysis of all cases diagnosed as of February 11, 2020. All COVID-19 cases reported through February 11, 2020 were extracted from China's Infectious Disease Information System. Analyses included: 1) summary of patient characteristics; 2) examination of age distributions and sex ratios; 3) calculation of case fatality and mortality rates; 4) geo-temporal analysis of viral spread; 5) epidemiological curve construction; and 6) subgroup analysis. A total of 72 314 patient records-44 672 (61.8) confirmed cases, 16 186 (22.4) suspected cases, 10567 (14.6) clinical diagnosed cases (Hubei only), and 889 asymptomatic cases (1.2)-contributed data for the analysis. Among confirmed cases, most were aged 30-79 years (86.6), diagnosed in Hubei (74.7), and considered mild/mild pneumonia (80.9). A total of 1 023 deaths occurred among confirmed cases for an overall case-fatality rate of 2.3. The COVID-19 spread outward from Hubei sometime after December 2019 and by February 11, 2020, 1 386 counties across all 31 provinces were affected. The epidemic curve of onset of symptoms peaked in January 23-26, then began to decline leading up to February 11. A total of 1 716 health workers have become infected and 5 have died (0.3). The COVID-19 epidemic has spread very quickly. It only took 30 days to expand from Hubei to the rest of Mainland China. With many people returning from a long holiday, China needs to prepare for the possible rebound of the epidemic.