Hong Kong authorities have placed a public housing block under a three-day restraining order for more than 2,500 residents to undergo daily Covid-19 tests, after a suspected Omicron superspreader allegedly infected 16 other people in the building.
The order, which takes effect on Friday, was issued after top microbiologist Professor Yuen Kwok-yung inspected the Yat Kwai House at Kwai Chung Estate on Thursday evening with health officials. The infected husband of a woman who had previously tested positive for the Omicron variant had visited the building to collect items from the waste stations for recycling.
Residents must be screened daily for three days and will only be allowed to leave their homes after testing negative for the virus.
“I call on all residents here not to run away, otherwise you will easily bring the virus to communities all over Hong Kong,” Yuen said.
Earlier in the day, health officials, rushing to contain a growing wave of cases, ordered residents of about 20 buildings on Hong Kong Island to undergo mandatory testing after discovering the virus in wastewater samples.
Education chiefs also announced the cancellation of most classroom lessons next week after more pupils were infected as an Omicron cluster linked to the infected woman spread to several schools.
Yuen said it was decided not to evacuate residents of Yat Kwai House as no pipes or structural issues were found that could lead to the spread of the coronavirus. But he also acknowledged there was not enough space in government quarantine facilities or time to prepare for home isolation.
Authorities had reported only two confirmed cases and a number of preliminary cases at Yat Kwai House earlier Thursday, but by midnight, Yuen said, 16 people – 15 residents and a security guard – had tested positive, some confirmed with Omicron.
Residents of 12 households live on 11 different floors of the block.
Although the alleged superspreader also visited the Luk Kwai House and Chin Kwai House garbage stations at the estate, no confirmed cases have so far been reported in either block. A dozen cleaners from the three buildings would be sent to a quarantine camp.
Yuen said they believe the family member of the index case – the infected woman, who had recently returned from Pakistan and later tested positive after spending three weeks in a quarantine hotel – could have transmitted the virus to the cleaners real estate and security guards, who turn them into infected residents.
The husband also took items he had scavenged from garbage stations to sell on Nam Cheong Street. People who visited peddlers there were also told to submit to mandatory testing.
Dr Albert Au Ka-wing of the Center for Health Protection (CHP) said the alleged super-spreader had not disclosed his visits to the three buildings until genetic sequencing results showed possible links to the outbreak at Yat Kwai House.
“We need to investigate further to verify if he failed to remember or intentionally concealed this,” Au said.
Yuen and Au said they believed the superspreader brought the virus to Yat Kwai House on January 13, triggering an outbreak over the following days until January 16.
Meanwhile, more pupils from a number of schools were also confirmed to be infected on Thursday, prompting the Education Office to suspend in-person learning for most pupils from the week next, while a group linked to hamsters sold in a pet store has expanded to cover sister shops. , bolstering the suspicion that the virus had spread from animals to humans.
“We are very concerned that there are silent transmissions in the community,” CHP’s Dr Chuang Shuk-kwan said at an afternoon press briefing. “Therefore, we urge residents who have been to pet stores and are concerned about the outbreak to get tested.”
Health officials said sewage samples taken in Aberdeen, southern Hong Kong Island, tested positive and residents of around 20 buildings in the area were to be tested, but no lockdown was ordered.
The discovery of the Delta variant at the Little Boss pet store in Causeway Bay triggered the culling of around 2,000 hamsters, most of which were imported from the Netherlands. Eleven samples taken from the rodents tested positive and one vendor was found to be infected.
Authorities said one person who visited the store and another who visited its sister store, I Love Rabbit, in Mong Kok were believed to have been infected. An environmental sample taken from a hamster cage at a Yuen Long branch of I Love Rabbit also came back positive.
Professor Leo Poon Lit-man, from the University of Hong Kong’s School of Public Health, said the latest genome scans revealed significant similarities between the samples taken from the hamsters and the vendor, suggesting that animal-to-human transmission had occurred.
While those samples shared similarities, the saleswoman’s virus had a difference of four genetic mutations from the one that infected two other people – a customer and her husband, authorities said.
“It’s possible that [the saleswoman] did not directly transmit the [virus] to the customer,” Chuang explained. “The client stayed in an environment where there are animals and she has a hamster at home, so we don’t know what the exact source of the infection is, but it is possible that a transmission from the animal to man has occurred.”
Government pandemic advisers have sought to explain the need for the ongoing cull and some have become targets of threats. Chief Executive Carrie Lam Cheng Yuet-ngor’s office issued a statement condemning the posts.
“The government strongly condemns the irrational attitude taken towards anti-epidemic efforts, and even worse, the bullying statements made against experts, by a minority of people. It calls on all sectors of society to come together to fight the epidemic,” a spokesperson said.
Ten of the 14 new cases were local, while the other four were imported. The city’s official count stands at 13,096, with 213 related deaths. Around 20 preliminary positive cases have also been reported.
Officials said they were unable to determine the source of four of the latest cases, bringing the total number of untraceable infections in the current outbreak to six.
Among them was a student living in Kwun Tong who carried the Delta variant, which had a different genetic sequencing from the virus that infected the Little Boss saleswoman, according to Chuang.
She noted that the student had no direct contact with animals and had not visited any pet stores recently, suggesting he was likely to have been infected by an unknown human carrier.
Authorities released new details of an untraceable case that emerged on Wednesday involving a kindergarten teacher who lived in Mei Foo Sun Chuen. She had an encounter with two infected students, linked to a group of quarantine hotels, which lasted just nine seconds.
Her Octopus card transaction history showed she had walked through a tunnel at an MTR exit around the same time as the two students last Friday. A friend who dined with her was among the latest confirmed infections.
“That’s the only possible common path we could find right now. Of course, if there are other cases such as [meal sharing] …this may further explain the infection,” Chuang said.
The government also revealed that children as young as five could start receiving the Covid-19 vaccine from Sinovac on Friday and shots from BioNTech from February 16. Reservations for Sinovac will open for children on Friday at 8 a.m. and for BioNTech on February 9.
According to the arrangement revealed by the Office of Education, all secondary schools must suspend in-person learning from Monday, but sixth form students studying for the April Secondary Education Diploma exams will be still allowed to go to class, but not more than half a day.
Students in other classes will not return to campus until at least February 7. The provisions, which came into force in kindergartens and primary schools earlier this month, also apply to tutoring centres.
The suspension came after the Omicron cluster, believed to have been triggered by a cross-infection at the Silka Seaview quarantine hotel in Yau Ma Tei, spread to several schools. The woman, who lives in Sham Shui Po, tested positive days after her three-week hotel quarantine ended, bringing the virus into the community.
The cluster has grown to 24 people, including a teacher and four students from Delia Memorial School (Broadway) in Mei Foo.
Authorities also said three students from other schools were confirmed to be infected after visiting the home of a student with the virus.
All of the affected schools – Delia Memorial, HKMA David Li Kwok Po College in Tai Kok Tsui, Buddhist Fat Ho Memorial College in Tai O and Lantau International School on Lantau Island – had already suspended face-to-face classes.
Respiratory medicine specialist Dr Leung Chi-chiu told a radio show that a “network” of infections could form among schools, families and those who interacted socially with students if classes in no one was suspended.
He also urged schools to keep classes online so students stay home and don’t go out for social gatherings.
The bureau last Friday suspended primary schools and kindergartens until after the Lunar New Year, but city leader Carrie Lam Cheng Yuet-ngor refused to impose similar measures on secondary schools, claiming at the time that older students could do better.
Nam Ching-sze, principal of HK Wesley College Methodist Church, expressed concern that on-campus learning could be suspended indefinitely given the ever-evolving epidemic, affecting mental well-being and student learning outcomes.
Halina Poon Suk-han, principal of Christian & Missionary Alliance Sun Kei Secondary School, said all secondary school principals began to prepare for the suspension after primary schools and kindergartens received the order to close classrooms last week.
“We don’t want to suspend classes but we have to accept it,” she said.
She and Lin Chun-pong, president of the Hong Kong Secondary School Principals’ Association, welcomed the flexible arrangement for sixth-grade students.
But Lin said schools were concerned about the impact of the suspension on students’ mental health, which could suffer when they no longer interact with their peers in person.
This article was first published in South China Morning Post.