Hong Kong confirmed nine new Covid-19 cases on Monday, the day before the start of mass testing to identify invisible coronavirus carriers in the city, but arguments continued over the effectiveness and safety of the scheme.

More than 553,000 residents had signed up for the programme as of 6pm, while Hong Kong’s leader, her top ministers and bureau chiefs will take the lead and be tested at the government headquarters in Tamar.

Chief Executive Carrie Lam Cheng Yuet-ngor’s top advisers will also get tested before the weekly Executive Council meeting on Tuesday, a source said.

The scheme opens at 8am at 141 sample collection centres across Hong Kong’s 18 districts.

Testing at 97 stations, or 70 per cent, is fully booked for the first day, and at 14 of them for the entire period of the programme.

At a regular press briefing, meanwhile, Dr Chuang Shuk-kwan, head of the Centre for Health Protection’s communicable disease branch, said there were nine more confirmed cases on Monday, including two imported infections involving a pilot from Ethiopia and a domestic worker from the Philippines.

Among the locally transmitted cases was another resident of Hong Chi Lei Muk Shue Hostel, a home for the mentally disabled. Twelve residents and six staff members have now been infected.

Chuang said one more resident tested preliminary positive, pending confirmation.

Two of the local cases were of unknown source, including a patient who was 39 weeks’ pregnant and had been admitted to a medical and geriatric ward at Tuen Mun Hospital before her infection was confirmed.

Ten other women, including a pregnant patient who stayed on the same ward, tested negative for the virus.

One of fewer than 10 people who tested preliminary positive on Monday was a 64-year-old patient admitted to Pok Oi Hospital in Yuen Long for shortness of breath. The Hospital Authority said a radiographer and a patient care assistant had not worn appropriate protective gear and would be quarantined.

Monday’s case total matched the nine infections recorded a week earlier, which was the lowest daily rise since July 3, before the third wave of coronavirus infections broke out in the city.

The total tally stands at 4,810.

Covid-19 also killed another elderly resident on Monday.

A chronically ill 83-year-old patient, who lived at Choi Hung Estate in Ngau Chi Wan, died in United Christian Hospital, taking the number of fatalities to 89.

Hong Kong third wave

Tracking the spread of local Covid-19 cases

Earlier in the day, Secretary for the Civil Service Patrick Nip Tak-kuen urged the public not to treat voluntary Covid-19 testing as a joke, warning that pranks, including registering for the scheme with fake names, could become a police matter.

“The registration system was designed to be simple and easy to use, so there isn’t a verification step built in,” Nip told a radio show. “At the same time we are monitoring things at the back end to make sure there are no abnormalities, such as a large amount of registrations from the same address.”

Nip said the system was functioning normally, but added any pranks would be passed to the police if necessary.

There had also been eight complaints of stolen identities being used to register for the scheme, with police dealing with three of those on Sunday evening.

“I hope the process can work on an honour system and people will not waste public resources. The virus prevention effort is not a joke and should not be messed with just because of differing political views,” Nip said.

A group of activists led by Joshua Wong Chi-fung and the Hospital Authority Employees Alliance, a union representing frontline staff at public hospitals, called on Sunday for a boycott of the testing scheme.

They cited recent Swedish reports of high rates of 3,700 “false positive” results returned by test kits from BGI Genomics, a firm involved in the Hong Kong programme, and questioned the accuracy of citywide testing.

In response, Sara Ho Yuen-ha, a chief manager at the authority, said that universal testing “aligns with the strategy of early testing, early isolation and early treatment”.

Opposition lawmaker Kwok Ka-ki, a doctor by profession, questioned the efficacy of the scheme if there was no stay-at-home order also in place to prevent further spread of the virus.

“There needs to be some measure to stop the spread of the coronavirus at its source,” he told a radio programme.

Commenting on the sign-up rates, Kwok said: “As a community-wide testing scheme, I would say it is quite a failure.”

However, pro-establishment lawmaker Vincent Cheng Wing-shun, who had been helping at roadside stations set up to support residents with the sign-up process, said the scheme had been well-received.

“But there are many misunderstandings related to the process, so I hope the government can make things clearer,” he said.

Meanwhile, a spokesman of the pro-government health workers’ group Medical Conscience, Dr David Lam Tzit-yuen, addressed concerns from residents who were worried about being infected during the testing process.

“I think the risk should be quite low,” said Lam, one of the programme’s 6,000-strong workforce. “The scheme is for people with no symptoms, so the risk is no higher than just going outside.”