A worker arranges boxes of imported frozen meat at a cold storage at Dalian port in Dalian, northeast China's Liaoning Province, April 8, 2020. (Xinhua/Yao Jianfeng)

Four asymptomatic COVID-19 patients working as loaders in an import cold-chain company have been found in Dalian, Northeast China's Liaoning Province, signaling a possible recurrence of the epidemic in the coastal city this winter.

The four were found to be infected with the virus during a routine test on Tuesday. They work as loaders in Dalian Yidu cold-chain company, the local government announced late Tuesday.

The local government has sealed off related cold-chain foods, and none of the products have reached the market.

This is the first time that Dalian has seen domestic infections since its previous wave in July 22, in which a total of 118 positive cases were reported. The outbreak ended on August 30, and no local cases had been reported since then.

Wu Zunyou, chief epidemiologist at the China Centers for Disease Control and Prevention, said on Tuesday night that the probability of recurrence in winter is high in places where there have been outbreaks previously.

"Generally speaking, places where an outbreak has occurred are more likely to have an epidemic in winter than in other places," Wu said.

Global Times