Two gatherings at two estates in Chai Wan and Sham Shui Po were revealed to be the crucial link in a small cluster of at least seven patients infected with the highly contagious South African Covid-19 variant that originated from a visiting Indian engineer and spread to three Filipina women, authorities said last night.
Further contact tracing found that a 29-year-old Indian man arriving from Dubai who was confirmed with the variant on April 16 and his 31-year-old female friend had attended a gathering with the woman's family at Fung Hing House, Hing Wah (II) Estate, in Chai Wan on April 13.
Subsequently, three people at that gathering on April 18 held another party at their home at 37 Ruk Wing Street in Sham Shui Po with the three helpers - a 39-year-old living at Caribbean Coast in Tung Chung, a 46-year-old living at Kornhill in Quarry Bay and a 38-year-old living at Royalton in Pok Fu Lam.
The latter two were among six new cases reported yesterday - three imported from Nepal and three local infections. This takes the tally to 11,797, including 210 deaths.
The Centre for Health Protection yesterday said both helpers were asymptomatic and their infections were picked up from mass testing for all 370,000 foreign domestic helpers from Friday. The two are friends who often spend their rest days together.
Sources said the 46-year-old had taken her first dose of the German-made BioNTech/Fosun vaccine on April 18.
The three attendees of both gatherings could be silent carriers, having contracted the coronavirus from the Indian man and his friend and passed it on to the three helpers. The transmission chain would involve at least seven known cases, including the five friends and the Tung Chung helper's female employer, whose 10-month-old daughter was also infected.
The Centre for Health Protection said it had immediately arranged for those who attended both gatherings to undergo compulsory quarantine.
Sewage samples from Fung Hing House have recently tested positive, prompting authorities to issue compulsory test notices to the block on Monday for all residents to test by today.
Compulsory test notices were also issued to residents of 37 Fuk Wing Street to be tested by today.
Two people who attended the gatherings worked in Central at Urban Bakery Works in Landmark Atrium and Oliver's the Delicatessen at Landmark Prince's.
Both sites have been added to the mandatory tests' list.
On Monday, the center said they found the Indian man, his friend and the Tung Chung helper had all visited Citygate mall on April 11 and suspected they could have come into contact there.
At the time, the center's head of communicable disease Chuang Shuk-kwan had said it was normal if a person could not remember clearly about his whereabouts a month ago, but if he deliberately hides information, authorities could take legal action.
According to the Prevention and Control of Disease Ordinance, a confirmed case or a close contact refusing to disclose relevant information or provide misleading information could be subjected to a maximum fine of HK$10,000 and six months in jail.
Around 230 households from N2 block of Quarry Bay's Kornhill and 30 households from Royalton, Pok Fu Lam, were sent to Penny's Bay quarantine camp yesterday, putting strains on the city's quarantine capacity.
Shortly after midnight yesterday, authorities announced both helpers carried the N501Y and E484K Covid-19 mutants - the variant first detected in South Africa - triggering lockdowns at the two blocks to test all residents in the morning, before sending them to quarantine centers for 21 days.
At Kornhill block N2, mobile test stations were set up around 7am and residents started to line up for tests around 10am. Some people rushed to the site to bring quarantine supplies for their relatives living in block N2.
As of 9am yesterday, before residents of the two blocks were moved to quarantine, 1,823 people were already in quarantine centers and the SAR's biggest quarantine center at Penny's Bay on Lantau had 1,950 out of 3,500 units available.
The other three isolation facilities at Lei Yue Mun Park and Holiday Village in Chai Wan and quarantine hotels in Silka Tsuen Wan and Dorsett Kwun Tong have 792 out of 1,149 units ready for use.
Meanwhile, residents in another locked down estate, Allway Garden in Tsuen Wan, complained about the arrangements.
Authorities told Allway's block R residents they would be sent to quarantine earlier on Tuesday, after a helper was diagnosed with the Covid-19 mutant strain infection.
But several hours later the building was locked down mandated residents were still waiting to be tested last night, before they could be evacuated to quarantine camps.