A single Covid-19 infection in any residential building, whether untraceable or linked, will trigger mandatory testing for everyone in the premises, as authorities take tougher action to bring Hong Kong’s health crisis under control before Lunar New Year. The new measure took effect immediately on Saturday, less than a week after the government lowered the previous compulsory testing threshold from two unlinked infections per block to one. Officials confirmed 19 new coronavirus infections citywide on Saturday, three of which were imported and six untraceable. This took the city’s overall tally to 10,608, with 186 related deaths. Around 20 people tested preliminary-positive for the virus. Authorities conducted their now-daily lockdown operations, this time at Wah Fat Building in To Kwa Wan at 8pm and Tower 9 of Hong Kong Gold Coast Phase II in Tuen Mun at 8.30pm, to enforce compulsory screening of residents overnight. Crowd control measures at Hong Kong’s flower markets, city logs 19 Covid-19 cases Lockdowns in Yuen Long and Ma On Shan uncovered no cases the previous night after 1,033 residents were screened, but two people were fined HK$5,000 for not getting a test within the set time. The Centre for Health Protection’s new chief , Dr Ronald Lam Man-kin, also announced that starting from Tuesday, anyone entering construction sites for the airport’s third runway must first present a negative test result, after multiple building sites were hit by outbreaks. Making his debut appearance as CHP head at the daily coronavirus press briefing by health authorities, Lam said the beefed-up testing drive would “put the city a few steps forward” in the fight against the pandemic, by uncovering hidden asymptomatic patients. “We are right now at a very important crossroad. You can see the cases daily are a bit swinging up and down, so it is quite, we believe, critical that we have to further strengthen our measures in order to compress the cases downward further, so we would try to aim at target zero,” Lam said. Five buildings citywide were slapped with a mandatory testing order following the rule change. “Suffice to say there will be a significant increase [in buildings put under mandatory testing],” Lam said. “To what extent is not very predictable because it depends on … the cluster distribution and how many imported versus local cases.” Do more to persuade public that Covid-19 vaccines are safe: Hong Kong ‘Sars hero’ He said contact tracing had improved “vastly”, with 4.5 close contacts identified for each patient on average, after the recent establishment of a tracking centre staffed by health and disciplined services officers in Kai Tak. But Lam urged residents to keep their guard up and maintain social distancing during the coming festivities. “Lunar New Year is approaching, we hope residents will reduce going out, avoid gatherings and meals, and fight this epidemic together.” The site at the third runway, where various subcontractors are employed, accounted for three more infections on Saturday, taking the total to 27 cases – 15 workers and 12 of their close contacts. Lam said the new, regular screening of the construction workers would be carried out every two weeks, and the Airport Authority had offered to train its security guards to check virus test certificates onshore before allowing employees to enter the building sites on reclaimed land. Hong Kong teachers seek end to Covid-19 testing plan The government would also offer all construction sector workers, estimated at between 100,000 and 200,000 in total, another round of free, one-off voluntary tests, Lam added. Industry groups the Construction Association and Construction Industry Council, which regularly inspect building sites and offer free Covid-19 screening, will also draw up new, stepped-up testing plans for the sector’s workforce and announce them next week. Respiratory medicine specialist Dr Leung Chi-chiu praised the authorities’ latest action to increase testing. “Since the number of Covid-19 infections has started to drop, testing needs to be expanded because it is harder to find new cases and cut down chains of transmission,” he said. But more needed to be done, such as setting up additional mobile stations to boost voluntary testing, he added. “Authorities can’t just rely on compulsory testing or lockdowns. They must also find ways to encourage those who live or work nearby to get tested so more of the population is screened,” Leung said. Meanwhile, neighbouring Macau received its first batch of 100,000 Covid-19 vaccines from Beijing on Saturday. It will commence vaccination with the mainland-produced Sinopharm jabs for priority groups, including medical staff, starting on Tuesday. Hong Kong is still waiting for Sinovac – another mainland-based vaccine maker from which it has secured 7.5 million doses – to provide more clinical trials data so its product can be approved. In light of the delay, the government said in a statement on Friday night that Sinovac would provide its raw Phase 3 data from its Brazilian trials – the same set it recently submitted to the World Health Organization – so the expert panel could begin its assessment while waiting for the peer-reviewed research. Separately, the city’s traditional Lunar New Year flower markets opened on Saturday under stringent infection control measures, which included a “traffic-light” alert system to indicate the crowd size at the 15 major ones.