Bad Ventilation May Have Caused TST Outbreak: Expert

Hong Kong University microbiologist Yuen Kwok-yung said bad ventilation at a restaurant in Tsim Sha Tsui might have caused a coronavirus cluster there.

Forty-eight cases -- including 22 customers and nine staff at Mr Ming's Chinese Dining, along with their close contacts -- have been confirmed with the virus, and there was also a preliminary positive case.

Speaking after inspecting the restaurant on Monday, Yuen said ventilation pipes were not supplying enough fresh air to the restaurant, and there was “an area of stagnation” so there might have been airborne transmission within a short distance.

“We find that the pipes carrying the air are very narrow. And then, when the [Electrical and Mechanical Services Department] staff measured the fresh air being supplied, it is only one-third of the expected amount,” Yuen explained.

“That, in an indoor situation, with such a low degree of ventilation, will definitely be predisposing to an outbreak,” he said.

Yuen said he also saw that dirty dishes were put in the same area where tea was being prepared. As clean and dirty items were not separated, he could not rule out cross-infection.

The expert said he'd also inspected other parts of the K11 MUSEA shopping mall where the restaurant is located, and has found the mall to be generally safe as ventilation is good. Authorities have earlier ordered mandatory testing for everyone working at the mall.

The mall has announced that it will be closed until Friday to make sure all staff get tested.

Speaking alongside Yuen, the Centre for Health Protection’s Dr Ronald Lam said what happened at the restaurant is “a little worrying” as a second generation of infections has emerged.

He said authorities are still tracing 15 more customers who ate at the restaurant after February 18 so they can be tested and quarantined.

Lam said since some patients had sought treatment at the clinic of private practitioner Wong Chung-yan, health officials are ordering people who have been to the clinic in Tai Kok Tsui since February 22 to get tested.