Among the Korean patients, 15 were men (53.9%). It has been reported that 56%–73.2% of confirmed cases of COVID-19 in Wuhan, China are in men [4,5]. The estimated incubation period was 4.6 days to develop COVID-19, which was shorter than the period of 5.2 days reported in China [5]. The mean age of the Korean patients was 42.6 years, which was lower than the age reported in previous studies conducted in China (49 years, 55.5 years, and 59 years) [2,4,5].