Referring to the general outlook after Thursday’s figures were revealed, Professor David Hui Shu-cheong, a respiratory medicine expert at Chinese University, said: “The situation is improving.

“Those who returned from overseas before March 19 and were infected should have already developed symptoms [if they were infected abroad] ... we were fortunate to see that there wasn’t a spread of community outbreak caused by this group.”

He was referring to the date when mandatory home quarantine came into place for all people arriving from overseas. He said any infected traveller who entered the city before the measure came into effect would have fallen ill on April 1 at the latest, factoring in the 14-day incubation period of the coronavirus.

“Now it is easier to control the situation. It is a good sign,” he said, noting that more new arrivals were being tested than a few weeks ago.

According to data from the Centre for Health Protection, March 19 was the date when most people – 43 in total – developed symptoms in the city, but the daily figures have since declined to single digits this week. The figure, which is different to the tally of confirmed infections, does not account for patients without symptoms, who make up about a quarter of cases from the past week.

The centre however anticipated the occupancy of quarantine facilities, for close contacts of confirmed cases, would remain high. It announced on Thursday night that, starting in phases from Saturday, people requiring quarantine at government facilities would stay there for the first 10 days and be put under home quarantine for the remaining four days, to ensure adequate supply of places.

Executive councillor Dr Lam Ching-choi said the virus’ reproductive rate had decreased from 1 to around 0.7 in the past few days, meaning each confirmed case only infected 0.7 other patients on average.

“It can prove local infection, especially with unknown sources, is pretty much under control,” he said. “But of course we still need to be vigilant, and if the rate in the coming week remains below 1 and local infection cases remain single-digit ... we could consider relaxing some of the social-distancing measures if the situation remains stable for the next two weeks.”

Dr Leung Chi-chiu, chairman of the Hong Kong Medical Association’s Advisory Committee on Communicable Diseases, also agreed a downward trend of infections was emerging, as fewer than 30 cases had been reported on each of the six days since Saturday.

But a more reliable guide, he said, would be to look at whether the number of people catching the virus locally trended downward for a period of seven to 14 days after April 1, when the last major infection control measure – closing a variety of social venues, including karaoke lounges and nightclubs – came into effect.

“That would allow us to see whether local chains of transmission have been decisively cut off, which is more important in terms of controlling the infection. Only then can we start to relax some social-distancing measures, starting with the reopening of some venues.”

Hong Kong police find another TST bar packed amid government-mandated shutdown

Speaking at the daily press conference, Dr Chuang Shuk-kwan, head of the Centre for Health Protection’s communicable diseases branch, said more time would be needed to determine whether Hong Kong had turned the corner on containing its infections. “The figures for one day cannot represent the overall trend, even though the numbers have been gradually slowing down. We hope this is a good sign.”

She noted that there were still cases with unknown infection sources and there could be hidden transmissions in the community.

Dr Ho Pak-leung, a microbiologist from the University of Hong Kong, also expressed caution despite the small daily tally.

“I won’t be too optimistic at this point despite the cases drop,” Ho said. “There are still locally transmitted cases, including those with unknown sources, and clusters cases.”

Among the 13 newly diagnosed patients, 10 had recent travel history, including two students. Among those believed to have been infected locally was a 37-year-old man whose baby was found to have contracted the coronavirus last week. The infant was 40 days old at the time.

The father, who was indirectly linked to the previously reported bars cluster, together with one more newly infected bar customer, brought the total in the group to 100.

Chuang also mentioned the case of a 43-year-old man whose source of infection remained unknown. She said the patient, who lived in Sheung Wan with his family, worked in Lee Gardens in Causeway Bay and usually jogged near his home and ate in fast-food shops.

Regarding the 57-year-old operations assistant from Shek Wu Hui Jockey Club General Out-patient Clinic who was reported as infected on Wednesday, Dr Sara Ho Yuen-ha, the Hospital Authority’s chief manager for patient safety and risk management, said so far 49 staff members at the clinic and another one in Ta Kwu Ling, where the woman had also worked, had been tested and all returned negative results.

Another 54 clinic employees would also be tested on Thursday.

Ho said five employees considered close contacts of the woman remained in quarantine. The 40 environment samples collected in the Shek Wu Hui clinic also showed no traces of the virus.

Ho said 29 more Covid-19 patients had been discharged, bringing the total number of recovered patients to 293.

An occupational therapist from Kwai Chung Hospital, who was said to have tested “weak positive” for the virus on Wednesday night, turned out to be negative.

Separately, 141 recovering Covid-19 patients had been transferred to tier-two isolation wards, facilities converted from general ward beds.

Meanwhile, restaurant group Cafe de Coral announced on Thursday that its outlets would resume evening dine-in services from 6.30pm on Friday. Resumption of services – which had been suspended since March 27 – also applied to the group’s Super Super Congee and Noodle, Mixian Sense and Oliver’s Super Sandwiches.

Additional reporting by Lilian Cheng