In the 16 index cases imported from abroad, the suspected sites where the infection was first contracted were Wuhan, China (11 cases, 68.3%), Singapore (2 cases, 12.5%), Zhuhai, China (1 case, 6.3%), Thailand (1 case, 6.3%), and Japan (1 case, 6.3%). The 10 patients with secondary infection for which the routes of transmission were known were either family members (7 cases, 70.0%) including relatives (2 cases), or acquaintances (3 cases, 30%) of the primary patients. The suspected sites of transmission were the home (7 cases, 70.0%), a restaurant (1 case, 10.0%), a church (1 case, 10.0%), and other locations (1 case, 10.0%).