Small-scale evacuation at Laguna CityTop News | Jane Cheung 26 Jan 2021
Residents of all E-lettered flats at Laguna City block 5 in Lam Tin have been moved to a quarantine center after 10 people came down with Covid-19. Experts suspected vertical transmission through pipes and the light well for the spread.
At the same time, the public is urged to avoid attending Queen Elizabeth Hospital in Jordan after three nurses tested preliminary positive, according to the Hospital Authority.
The evacuation at Laguna City - the first at a big private estate - came after 10 people, including four helpers, from five units in the 27-story block 5 were infected.
There were three infected E flats from the 15th to 17th floors, as well as 26D and 17F.
Government adviser Yuen Kwok-yung from the University of Hong Kong, who inspected the building yesterday, suspected there were two reasons for the outbreak.
One is a family gathering at flat 16E on January 9, after which a guest was diagnosed with Covid-19. Another involved two infected security guards, one of whom lives on Reclamation Street in hard-hit Jordan.
"We haven't spotted problems in the pipes," said Yuen.
"But there could be a chimney effect in the pipes or the light well. Flats D and E share the same light well so it's possible the virus from flats E was pumped out from pipes on the rooftop and went back down to flat 26D by the wake effect."
However, he said the U-traps in at least one of the infected units were dry, meaning they cannot block contaminated gas from entering the units.
Yuen again reminded people to regularly pour water into the U-traps.
He said authorities have yet to confirm how many residents will be moved out as it is a private building. Some E flats were interconnected with flats F and in this case those in flats F will also need to move.
Despite residents of the block being mandated to take the test by last Sunday, Yuen said only 463 out of an estimated 640 residents had done it.
The evacuation came as Hong Kong yesterday recorded 73 new cases, taking the tally to 10,159, including 170 deaths.
The Hospital Authority's chief manager for quality and standards, Lau Ka-hin, said three nurses from Queen Elizabeth Hospital tested preliminary positive.
Two of them have worked at isolation ward A10, one completed her six-week rotation to the ward on January 17 and returned to internal medicine ward E6 the next day. Both wore full protective gear in the isolation ward.
They only had a short interaction on work issues on January 13 when they worked the same shift, Lau said, adding the authority believes their cases are not linked.
Lau said the third infected nurse had been working at internal medicine ward A6 and had not been in contact with Covid-19 patients. However, her residential building saw confirmed cases recently.
Ten other staff will be sent to quarantine as close contacts. The authority has arranged contractors to conduct voluntary tests on thousands of staff at the hospital from today.
Three out of 12 internal medicine wards have been suspended from new admissions, including E6 and A6. The third ward was A5, where a medic was infected last week.
Lau said even though Queen Elizabeth's accident and emergency department continues to operate, admission to internal medicine wards will take longer and he called for those with mild complaints to instead go to general out-patient clinics or private doctors.
The Centre for Health Protection's head of communicable disease branch, Chuang Shuk-kwan, said among 69 local infections yesterday, 38 were from unknown sources - a worrying sign for silent transmission chains.
One of the unknown-source patients is Chinese medicine practitioner Chung Kam-chuen. A Department of Health doctor who had visited him is a preliminary positive case. Clinic staff and other patients who have visited Chung during his infectious period - since last Thursday - will be sent to quarantine.
The Hospital Authority also said it will offer Chinese medicine treatment to Covid-19 patients at the community treatment center at AsiaWorld-Expo starting today.