Eight imported coronavirus patients, including two who had been seriouslyill, were discharged on Sunday upon recovery, the Shanghai Health Commission has announced.

Since March, Shanghai has had nine severe cases in all, includingtwo critical cases. All were imported cases, and all nine cases have been released by Sunday, the commission said.

Both of the two newly released serious patients were expatriates, who have underlying diseases. They arrived in Shanghai from their own countries for work in mid-September and were transferred to the Shanghai Public Health Clinical Center, a designated hospital for coronavirus patients, from quarantine sites after being confirmed with the infection.

Doctors believed their cases could become serious based on previous experience.

Doctors gave treatment in line with the patients' conditions and prevented further deterioration. They successfully controlled theconditions within two weeks.

Local health authorities have grasped scientific methods for the early alert of serious cases and effective treatment to control deterioration.

Facing the continuous pressure of imported cases and the upcoming China International Import Expo, the local health industry has made proper preparations to further improve health capability for coronavirus prevention and control.