JINAN -- Linyi City in east China's Shandong province on Sunday reported one imported asymptomatic COVID-19 case, the municipal health commission said on Nov 2.

The asymptomatic patient is a local resident of Linyi, who returned from the United States to Shanghai on Oct 14. During her 14 days of customs entry quarantine in Shanghai, her two nucleic acid test results were negative for COVID-19.

She took a flight to Linyi on Oct 29. Two of her nucleic acid tests were negative during the quarantine. Her serum antibody test, however, showed positive on Oct 30, when another nucleic acid test on her also showed positive.

The asymptomatic patient is being treated in a designated medical institution, and all close contacts have been tracked.