Teenagers stay for medical observation after the vaccination with their parents at a vaccination point in Shanghai, Aug 14, 2021. (Photo: Xinhua)

The Shanghai health authority confirmed two locally transmitted cases of COVID-19 on Friday, and more than 40,000 people with potential risk of exposure have been tested. One-fifth of the results were available by Friday evening — all negative.

Wu Jinglei, director of the Shanghai Municipal Health Commission, said at a news conference the two cases were service staff for an international cargo flight at the Pudong International Airport, whose regular nucleic acid tests gave positive results on Friday.

Experts at municipal and district centers for epidemic control confirmed the results with other clinical tests, and the two patients have been transported to the Shanghai Public Health Clinical Center for treatment.

The first case, 44, was a male Ethiopian mechanical engineer living in the Jielong Huayuan residential neighborhood; the second case, 45, was a male worker at the foreign cargo flight zone, residing in the Jinjiang Inn Hotel, Donghai township branch.

The patients' residential community and hotel were locked down, and elevated to medium-risk areas.