Fung Chak House in Choi Wan Estate Photo: Google Maps

Covid-19 virus was still found in samples collected from the sewage pipes at a residential block in Hong Kong ten days after residents there were tested with five people positive.

The Health Department issued a mandatory virus test notice to the residents at Fung Chak House of Choi Wan Estate in Kowloon. Anyone who had been at the building between December 15 and 28 will have to be tested by Saturday.

The virus was first found in sewage pipes on December 28, after which the residents were tested. Five were found to be infected.

Residents were required to be tested a second time when the virus was found in sewage pipes once more on Wednesday.

Citing advice from medical experts, Tsui Tak-yi, the Undersecretary for Food and Health, said some patients did not test positive during the first round of tests because they were at early stages of infections. Tsui said these patients continued to live in the building and contaminate sewage with the virus.

However, the government has no plan to seal off the building to find out whether some asymptomatic patients who skipped the test were hiding in it.

Tsui said 296 cases had been recorded in the city in the past week, 27% of which were untraceable. Also, he said about 26% of all patients were asymptomatic, creating risks that the number of cases could rebound suddenly and rapidly. He urged the public to remain vigilant to the social distancing rules.

Tsui added that people would soon be able to get test kits from post offices, MTR stations and facilities of the Hospital Authority.

The Center for Health Protection said 33 cases, four imported and 29 local infections, were recorded on Wednesday. Of the local patients, five had no known source. They included two retired people, one jobless person, a worker in Tuen Mun and a cleaner. More than 30 people tested positive preliminarily on Thursday.

Eleven more patients were found to be linked with the cluster at the construction site for the Tseung Kwan O – Lam Tin Tunnel. The site was forced to close between December 9 and 27 due to a virus outbreak but a supervisor tested positive last Saturday after the site’s operations resumed. The number of infected people in the cluster has grown to 27.

On Tuesday, the number of new cases dropped to 25, the lowest in almost seven weeks. Five cases had no known source. These included a domestic worker, a salesperson and a bus driver.

Chuang Shuk-kwan of the Center for Health Protection said she hoped the downward trend could continue, but that people should remain cautious because unlinked cases were still being reported from the community.

“This is one or two days’ figures, we may foresee some fluctuation during the week. But the overall trend has been decreasing, so this is a good signal,” she said. “But still there are quite a number of unlinked local cases in the community, so we are not sure whether we’ve picked up all the cases in the community.”

About 100 officers from the disciplinary forces, mainly police, immigration and customs officers, would join a contact-tracing team and help track down people who came into contact with patients, Chuang said Thursday. They would start working with medical staff at a new command center in Kai Tak from Monday.

“We will give them a briefing and then we’ll provide on-the-job training because the training may involve actual working under supervision,” she said.

Meanwhile, thousands of beauty parlor operators and their staff staged an online protest on Thursday, demanding that the government let them resume work.

Beauty parlors have been ordered to shut three times since the pandemic began, with the closures lasting more than 100 days in total, Federation of Beauty Industry chairman Nelson Yip said.

Yip said this was unfair because there had been no Covid-19 outbreak in the sector.

Chief Executive Carrie Lam said Tuesday that she understood that many businesses had been hit by the social distancing rules. She said some rules could be eased before Hong Kong achieved zero infections but it would still take some time for that to happen.

Read: HK residents tested after virus found in sewage

Read: HK reports 15 mutant virus cases in two weeks