The Chinese Center for Disease Control and Prevention (CDC) on Saturday confirmed the detection and isolation of living novel coronavirus on the outer packaging of imported frozen cod in the eastern coastal city of Qingdao.

The finding was made during an investigation to trace the source of recent infections reported in the city. It has proved that contact with packaging contaminated by living novel coronavirus could lead to infection, the China CDC announced on its website.

It is the first time in the world that living novel coronavirus has been isolated from the outer packaging of cold-chain food, the China CDC said.

The isolation of living novel coronavirus in Qingdao confirmed outside the laboratory that the virus can survive on the outer packaging of items for a long time under the special conditions of cold-chain transportation, suggesting that the virus has the possibility of long-distance cross-border transmission using cold-chain items as carriers.

Under certain environmental conditions, the virus on the surface of the items may cause infections in susceptible contacts without effective protection, and people at risk of infection are mainly practitioners of cold-chain items.

The relevant departments in China have recently carried out nucleic acid testing on cold-chain foods. A total of 2.98 million samples had been tested across the country's 24 provincial-level regions by Sept. 15, including 670,000 taken from cold-chain food or food packaging, 1.24 million from working staff and 1.07 million from the environment.

Only 22 samples from cold-chain food or food packaging tested positive for the virus, the China CDC said.

Existing research and practices in epidemic prevention and control show that COVID-19 is not a food-borne disease. No infection caused by food intake has been found.

So far, no cases of consumer infection due to contact with contaminated cold-chain seafood have been found, indicating that the risk of infection among Chinese consumers is extremely low. Therefore, the main route of the virus infection is still through respiratory droplets and close contacts.

Meanwhile, relevant departments have strengthened COVID-19 testing and disinfection of imported cold-chain food.