Dr. Owen Tsang Tak-yin, medical director of the authority’s Infectious Disease Centre at Princess Margaret Hospital in Kwai Chung, said that of about a dozen discharged patients examined, two or three were unable to function as they had previously.

“They gasp if they walk a bit more quickly,” Tsang told reporters Thursday, according to the news outlet. “Some patients might have around a drop of 20 to 30 percent in lung function [after recovery].”

Lung scans of nine infected patients at the hospital suggested they had suffered organ damage.

But Tsang said it had yet to be determined whether they would develop pulmonary fibrosis, a condition in which lung tissue hardened and the organ could not function correctly.