Wuhan has the highest number of deaths and mortality from COVID-19 in China to date, but the reason remains unknown. Here we compared patients with COVID-19 with a history of traveling in Wuhan with those who did not travel in Wuhan in the early stage of pandemic with respect to a series of clinical characteristics and laboratory parameters. We observed that patients who had traveled in Wuhan had an increased rate of severe disease and longer viral duration along with fewer CD4+ and CD8+ T cells, although there was no significant difference in viral load between the two groups.