HONG KONG - Leading microbiologist Yuen Kwok-yung said there is no need for Hong Kong to ban trading and shut down the SAR, and the pressing task for the city now is to sever the transmission chain.

Speaking at a local radio program on Thursday morning, Yuen said this could be achieved by avoiding more imported cases from the Chinese mainland and taking measures to prevent human-to-human contacts locally.

Yuen's comments came a day after the government announced it will tighten the border by requiring those who enter the city from the Chinese mainland after Saturday to be quarantined at home for two weeks.

The University of Hong Kong microbiology professor said Hong Kong, with an export-oriented economy, would not survive if it were to ban all business activities and lock down the city. Instead, the city should contain the virus and avoid a local outbreak so that Hong Kong itself would not be restricted by other regions, Yuen said.

Currently, Hong Kong recorded 21 confirmed infections. Among them, five contracted the virus locally and another three very likely did the same. According to the Department of Health, as of Thursday, a total of 78 buildings in the city house confinees who are under the 14-day house quarantine.

For those under house quarantine, Yuen advised that they should minimize interaction with roommates and family members. If the apartment is too small to do this, he suggested each family member eat in a separate room to lower the exposure to the coronavirus.