Dozens of police officers descend upon the street, hauling metal barricades and police tape behind them. Within minutes, hundreds of residents, shopkeepers, and bystanders find themselves trapped inside a police cordon. They will be unable to leave for at least 12 hours.
Scenes like these are becoming a regular occurrence in Hong Kong, as the government has imposed strict ‘ambush’ lockdowns on parts of the city to find unidentified cases of COVID-19 and reduce the spread of the virus.
The lockdown measures, which were first introduced in late-January, have happened almost daily. Lockdowns are unannounced, with various blocks and buildings being sealed off without warning.
The ambush lockdowns restrict people’s movement and allow for mandatory COVID-19 tests to be conducted for all people inside the lockdown area. The lockdowns typically begin in the evening, with tests being conducted for all residents throughout the night, and are lifted once all test results are confirmed by the next morning.
But with only a handful of cases being identified, the effectiveness of the Hong Kong government’s ambush lockdowns has come under scrutiny.
As of 5pm on Thursday, a total of 14 lockdowns have been implemented across Hong Kong, during which over 14,600 tests have been conducted. In all, just 15 positive cases of COVID-19 were found through this method of testing. This means the lockdowns have a positive-test rate of around 0.1 percent. The majority of ambush lockdowns have not seen the identification of any cases whatsoever.
“If the ambush lockdowns are finding zero cases, I don’t think they contribute much to bringing the fourth wave to the end,” said Benjamin Cowling, head of epidemiology and biostatistics at the University of Hong Kong. “If the lockdowns have identified lots of cases that we did not know about, then maybe it would help. But, with zero cases being found, I do not think it has much impact on the control of the fourth wave,” he explained.
Cowling added that, apart from older buildings with plumbing issues and household clusters, there has not been a clustering of infections within residential buildings. Instead, most transmission has been linked to social activities and workplaces like construction sites.
“You might have as much chance of winning the lottery as you’d have of finding a lot of cases in a single building in Hong Kong, because [cases] are spread out across the whole city,” he said.
Compliance with the lockdown orders have also become an issue. Around 16 percent of households under lockdown did not answer the door when visited by government officials. The government has threatened to take drastic measures against non-compliance, including breaking into units to enforce mandatory lockdown testing orders.
The government has also defended their use of ambush lockdowns. Speaking to the media on Tuesday, Chief Executive Carrie Lam said the objective of the lockdowns was to eliminate the transmission of COVID-19 in the community.
“To have zero transmission and zero infection is the best-ever public health achievement that could be made,” she said. “We will continue to do this type of compulsory testing in order to identify any remaining silent transmission cases in the community.”
Cowling, meanwhile, argues that there is always a trade-off between effectively tackling COVID-19 transmission and disrupting people’s lives.
“There is a balance to be found and I think if we have measures that are too disruptive, but not very effective, maybe we should tend not to use those measures,” he said.