People living in a public housing block in Kwun Tong are being ordered to take Covid-19 tests by New Year's Eve after the virus was found in sewage from their building.
Authorities said on Monday that residents of Fung Chak House in Choi Wan Estate, and anyone who visited the building since December 15, will be subject to mandatory testing after four sewage samples taken in the past five days came back positive for coronavirus.
Authorities say they must keep records of a negative result that they can show to law enforcement officers.
Checkpoints were set up outside a Sha Tin building last week where mandatory Covid tests were also ordered, with residents not allowed to leave without providing proof of a negative result.
While there haven't been any confirmed cases yet from Fung Chak House, Hong Kong University medical professor Gabriel Leung said the virus in the sewage is most likely coming from an asymptomatic carrier of the virus in the building.
"The likelihood is, that yes, there is some silent spreading going on, and that is why you're getting such consistent signals [with the sewage samples]. So it's a precautionary measure that the mandatory order has been issued," he told a press conference.
The sewage samples were taken by an HKU team after 15 people came down with Covid-19 in Ming Lai House, which is next to Fung Chak House.
The last patient left Ming Lai House to go into quarantine on December 16.
Leung said his team has conducted similar sewage tests at housing blocks where there have been recent outbreaks, such as Richland Gardens, Yuet Ming Estate and Kwai Shing West Estate, but none of the samples have come back positive.
Meanwhile, a drainage services assistant director, Eddie Pak, warned that any coronavirus in sewage could spread through the air from leaking pipes.
Last updated: 2020-12-28 HKT 12:55