Covid-19 lockdown lessons from Hong Kong: Surprise area testing yields results

Hong Kong has so far managed to stave off a fourth wave of the pandemic. PHOTO: AFP

HONG KONG - Six months after Hong Kong's leader announced a target of zero Covid-19 infections, the city on Thursday finally hit the seemingly ambitious goal even as the pandemic flares up in other places like Singapore and Taiwan.

Hong Kong has so far managed to stave off a fourth wave of the pandemic - what the Food and Health Bureau said was mainly caused by importation of cases - and bring local outbreaks under control.

The city continues to keep its daily infections low, at between zero and eight in the past month, despite a sluggish vaccination take-up rate. About 20 per cent of the 7.5 million population is inoculated, even though the city has been offering easy access to vaccines since late February.

To complement existing social distancing measures such as mandatory testing and border controls, the government also conceived temporary surprise lockdowns that are smaller in scale. Known as restriction-testing declarations, these night operations typically wrap up the next morning and will have anyone who is in the lockdown area tested for the virus - a move that has ruffled some feathers and drawn complaints about the inconvenience.

Since Jan 23, the government has carried out 47 such "ambush lockdowns" islandwide, involving 200 buildings and 40,000 residents. In all, 22 cases were detected.

Epidemiologist Ben Cowling, a professor at the University of Hong Kong, estimated that for every 10,000 people tested in these lockdowns, "it would probably be possible to identify a handful of unlinked cases". "It is very expensive and time-consuming to test large numbers of people who are very unlikely to be infected, as opposed to more traditional contact tracing," he said.

The operational goal is to have all relevant residents tested before the formation of transmission chains in the buildings, said the Food and Health Bureau, which expects "that some operations would yield zero cases".

Asked about the cost, the bureau said every operation typically involves a few hundred colleagues from various government departments and law enforcement agencies. "Expenses for the restriction-testing declarations operations are absorbed within the government's overall provision and we do not have a separate breakdown on the actual expenses or the relevant manpower," it added.

Dr Leung Chi Chiu of the Hong Kong Medical Association noted that the city does not have the community infrastructure or testing capacity to adopt a wide-scale lockdown seen in the mainland.

A key part of anti-epidemic efforts, he said, hinges on resident-initiated social distancing such as mask-wearing and hand hygiene to slow transmission. "It is not what measures the government has introduced that matter, but rather, the actual social mixing behavioural pattern of residents that decides how infection would spread."

He added that, ultimately, self-initiated social distancing measures are easier to comply with than "draconian lockdowns or curfews".

Lockdowns and curfews need to be in place "for a sufficiently long period of time to allow other control measures such as testing, contact tracing and mass vaccination, to contain transmissions".

Hong Kong has recorded more than 11,800 cases and 210 deaths since the pandemic swept its shores, numbers that are far below that of many other places.

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