Photo: IC

The outer packaging of a batch of domestically-produced chicken drumsticks returned positive nucleic acid test results, Lai'an county in Chuzhou of East China's Anhui Province confirmed on Wednesday. The incident marks the first time that COVID-19 was reported on local cold chain food products from local sources in China. 

The case was found in Wuxi of East China's Jiangsu Province, instead of Chuzhou, a staff from Chuzhou's epidemic control team told the Global Times on Wednesday. Wuxi's epidemic control team issued a letter asking Chuzhou to help with the investigation, he said.

On Tuesday, Wuxi's epidemic control team announced that a batch of frozen pigs' ears from the US company Premium Iowa Pork tested positive for coronavirus. The products have not entered the market. 

A staff member of Chuzhou's epidemic team said the letter from the Wuxi authority didn't mention the pig's ear case or if there is any relation between the two cases. "It said that the Chuzhou case was detected when local authority in Wuxi carried out a regular sampling on cold chain products," he said.

It didn't state whether the sampling was carried out during transportation or in the warehouse.

So far, it remains unknown how the package was contaminated. There is no evidence the coronavirus contaminated packaging of chicken drumsticks is related to the pig ear packaging. A final conclusion by relevant authorities is expected.

It is likely to have been contaminated by the packaging of imported food products during cold chain transportation, an immunology expert, who asked not to be named, told the Global Times on Wednesday.

Incomplete disinfection in the process, contamination after disinfection or via an infected cold chain worker are also possible, he said.

"If it is proved so, we need to strengthen disinfection in cold chain logistics and separate the transportation of domestic products and imported ones," the expert said.

The Global Times learned that Anhui's Center for Disease Control and Prevention has sent experts to Lai'an to join the investigation.

The drumsticks were purchased from a protein company in Laian county of Chuzhou, the Lai'an epidemic control team said. The company is owned by US food giant Cargill, the staff confirmed.

The local authority has started conducting nucleic acid testing among all company staff members as well as in relevant places. So far, 2,712 samples of nucleic acid testing have been collected, among which 2,313 returned negative; 399 are awaiting their results.

Besides, no positive test results were found in all 267 samples taken from cold chain transport vehicles, office spaces, cold storage, production lines and food.