A McDonald's restaurant in Yichang, Central China's Hubei Province Photo: CFP

US food corporation Cargill's major clients in China, including fast-food chain McDonald's, said that their supplies have not been affected by a positive coronavirus case involving chicken, adding that they did not source products from batches where the locally produced chicken drumsticks tested positive for COVID-19. 

Industry insiders said that the positive test may be a result of cross-contamination from imported cold-chain products. 

The drumsticks from Cargill's plant in Chuzhou, East China's Anhui Province were the first case in China of a domestically produced product testing positive. The company is also a provider to several international fast-food chain companies, including McDonald's and KFC. 

A representative from McDonald's told the Global Times that the Cargill plant did not produce any items related to McDonald's on the same day that the drumsticks in question were produced, and that McDonald's overall supply has not been affected. 

Cargill's clients, including McDonald's, declined to disclose the exact amount of chicken that they source from the company, but according to media reports, Cargill's Chuzhou plant - which opened in 2009 - has the capacity to butcher up to 40 million chickens every year. All chicken products are made from broilers from its own farm. 

Fan Xubing, president of Beijing Seabridge Marketing, a cold-chain food importer, told the Global Times that the contamination may well have come from staff moving different products from the containers to the warehouse, but companies and the government "must be cautious" in regulating the purchases and sales of its products. 

"The impact on the big companies' supply is limited, because they usually have very diverse suppliers," Fan said. "The contamination may have taken place because staff who moved the products had touched imported products as well."

On Thursday, the local epidemic control team in Anhui said that after the positive case was found, it tested 423 samples taken from raw materials, production lines, cold-chain transfer vehicles in the factory, and 2,712 staffs from the company, all of which came back negative. 

The statement said that the product was possibly contaminated in cold-chain logistics or from other links outside the province.