Nanjing, East China's Jiangsu province, reported one case who tested positive for COVID-19 on Tuesday, according to the local health commission.

The patient, who works under a closed-loop management for the Nanjing section of the Yangtze River Pilotage Center, has been sent to a designated hospital for treatment.

The case was initially detected during a routine 1:5 mixed sample nucleic acid testing for port workers at high risk of infection, and subsequently verified.

The remaining four individuals in the mixed sample and some close contacts have been quarantined, and the local government has carried out origin tracing, disinfection and nucleic acid testing of contacts since it received the report around 3 am.