Covid feared to have spread in Tai Po housing block

Authorities said on Sunday that residents of around 20 flats in a Tai Po building are being sent into quarantine over fears Covid has spread through the block.

Dr Albert Au from the Centre for Health Protection (CHP) said a 66-year-old woman who lives alone in Mei Sun Building has tested positive for Covid, after a helper, her employer and a teenage girl who live a few floors below came down with the virus.

Microbiologist Yuen Kwok-yung, who advises the government on the pandemic, said the woman living in unit 10D was probably infected by the trio living in unit 5D, and the altered pipes of the tenth floor flat were probably to blame.

“The most probable reason is what we call the chimney effect, meaning warm air rises in the pipe, and in this case, in the waste water pipe. The air reached unit 10D, where the washroom had been altered and the shower had not been used and hence the u-shaped trap in the drainage pipe was probably dry. So… the [contaminated] air entered the unit and infected this lady,” he said, after inspecting the building with other government officials.

The CHP’s head, Dr Edwin Tsui, said all unit D residents from the sixth to the 24th floors of the block would be taken into quarantine as soon as possible, while other residents would be tested during a lockdown on Sunday night.

The 66-year-old woman first tested negative when the building was put under lockdown on Thursday, but another test on Saturday came back positive.