Fig. 2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission chain from contaminated cold chain foods in warehouse to human in Dalian between December 15, 2020 and January 2, 2021. Four stevedores and one worker were found to be SARS-CoV-2 positive and were identified as asymptomatic infection in Dalian port on December 15, 2020. The extensive epidemiological investigation and molecular epidemiological analysis identified the virus transmission chain across Dalian City. The epidemic in Dalian was mainly caused by the personal activities of a dockworker (stevedore) who was infected through close contact with the above four stevedores infected with SARS-CoV-2 virus. In 18 days, there were 83 cases of infection in Dalian