The sample, imported from Russia, tested positive during a regular COVID-19 screening Friday and the result was confirmed by the municipal center for disease control and prevention Saturday.
Changchun's health authorities have traced people who had been exposed to the package and put them under medical observation. All the people tested negative for the virus.
An item of the product weighing 10 kg entered the city of Fuyu in the province, according to an announcement by the city's epidemic prevention and control authorities Sunday.
The city's health authorities have asked people who may have contacted the product to report to the local community or village and receive nucleic acid tests for COVID-19.