Partial evacuation and a second lockdown for Tai Po building after vertical Covid transmission

Residents in units D between the sixth and 24th floor of Mei Sun Building in Tai Po will evacuate to a quarantine center while the block will be under lockdown again on Sunday night, after experts found vertical transmission in the building.

Government advisor Yuen Kwok-yung inspected the building on Sunday afternoon for a 66-year-old woman living in unit 10D tested preliminary positive just days after an Indonesian helper and her employer living in unit 5D were infected.

He believed the coronavirus was transmitted through a wake effect, where coronavirus-carrying air went from lower to upper floors.
As a result, he advised authorities to evacuate all residents living in units D on the sixth floor and above.

Controller of the Centre for Health Protection Edwin Tsui Lok-kin confirmed the evacuation, saying that all households living in units 6D to 24D had to move to Penny’s Bay.

He also said that the building will be locked down again on Sunday night for compulsory testing. The rest of the residents have to obtain negative test results before being allowed to leave.

Yuan explained the wake effect was caused when warm air in the pipe went up to the modified toilet in unit 10D.

However, the shower in the modified toilet had not been used for a long time and the U-shaped water trap had dried up and was unable to segregate possible contaminated air from vertical units.

In addition, the building came with a lightwell. So if other residents turned on the exhaust fan, virus-carrying air could be pumped into their homes.

An Environmental Protection Department officer said that the drains in the building are in good condition and have just been repaired in 2018, but the ones in unit 10D had been altered and a toilet set has been added to one of the rooms, which is suspected to have caused the spread.

The 51-year-old Indonesian domestic worker living at Mei Sun Building was confirmed of Omicron infection on Friday. She visited a Bethel Fellowship church in North Point on January 2 with another 43-year-old Indonesian domestic helper who tested positive on Wednesday.

She was on Wednesday classified as a close contact of the 43-year-old and went to Tai Wo Sports Centre for a Covid test on the same day.

Her employer, together with his children, was sent to Penny's Bay Quarantine Centre and both were confirmed on Saturday.