The SAR government has decided from today to put all visitors and returnees entering Hong Kong from outside the city under quarantine for at least 14 days. It is a sensible step in containing the spread of the novel coronavirus, as the pandemic is now raging in most if not all foreign countries; imported cases have accounted for over 90 percent of new infections recently. This is particularly necessary for people from the United States, United Kingdom and many other developed Western economies because their governments gave the pandemic a comfortable head start by doing little to prevent it from spreading. Testing is conducted only on a very small scale in many of these countries.

Conceivably, the real challenge and risk will be posed by the influx of returning students in such a short period of time

Some quarters of society have pressed for a complete lockdown of the city, banning all nonresidents from entering the city for a certain period of time. But this is unrealistic and impracticable if Hong Kong is to retain its status as an international financial, commercial and logistics hub. The mandatory 14-day quarantine requirement is arguably enough to stop overseas visitors from making unnecessary trips to Hong Kong. Mainland visitors to Hong Kong have dropped drastically to just a few thousands from hundreds of thousands a day after the SAR government on Feb 8 required all those entering the city from the mainland to be quarantined for 14 days.

Conceivably, the real challenge and risk will be posed by the influx of returning students in such a short period of time. Hong Kong is notoriously short of well-ventilated indoor spaces that can be used as temporary quarantine facilities. The government therefore has to require those who have permanent residence here — specifically, student returnees — to self-quarantine for at least two weeks at home. Tens of thousands of Hong Kong youth are expected to rush back from the US, the UK and mainland European countries as universities there shut down their campuses to stop the spread of the coronavirus.

The key to preventing another community outbreak or clustered transmission lies in effective quarantine measures. The SAR government has done its best to mobilize thousands of civil servants and volunteers to help ensure those under self-quarantine follow these instructions faithfully. But they can be overwhelmed by the task of ensuring tens of thousands of people follow the quarantine rules. Arguably, whether Hong Kong people are spared a second community outbreak depends on the returnees’ ability to exercise self-discipline while self-quarantined.