Groups that were overlooked could be behind Hong Kong’s recent surge in coronavirus cases, experts have said, with the Post finding that three in 10 imported Covid-19 infections came from sea or aircrew members, while one in four came from domestic helpers.

As the city grapples with the third wave of a health crisis threatening to spin beyond control, doctors said holes in the city’s border measures, compounded by a delayed government response and public complacency, have led to the unprecedented outbreak.

Hong Kong’s daily count of infections hit a record high on Sunday, topping 100 and outstripping the previous peak of 65 in March during the second wave, with the current total tally of 1,958 surpassing 2003’s severe acute respiratory syndrome numbers.

The dreaded third wave emerged more than a fortnight ago on July 5 when a cook in a local restaurant got infected. The latest round of cases have involved elderly care homes, leading to a cluster of 44 patients linked to the Kong Tai Care for the Aged Centre Limited, as well as the district of Tsz Wan Shan, which has so far recorded more than 150 infections.

Facilities at the city’s public hospitals have also been stretched close to breaking point, with occupancy rates of isolation beds and wards reaching 71 and 77 per cent respectively, while 1,450 units at quarantine centres are occupied, with only 196 slots still available.

The government stepped up its coronavirus response on Sunday with a raft of measures, including in a U-turn, ordering civil servants to work from home from Monday and keeping only emergency and essential public services open. It also extended the ban on dine-in services at restaurants from 6pm to 5am for a week to July 28, and announced it would make mask wearing mandatory in indoor public places such as shopping centres.

But some experts said the loophole had existed for a long time, and only closed partially when on July 8, the authorities tightened border measures and required sea and aircrew members to produce negative Covid-19 test results before coming to the city, as well as those arriving at the airport to head to the AsiaWorld-Expo for mandatory testing.

A Post review of data from the Centre for Health Protection revealed that of 111 imported Covid-19 cases since July 8, 34 are members of sea or aircrew. Their infections were only detected after mandatory testing was introduced. This represented 30 per cent of the city’s imported total.

“The figure is just the tip of the iceberg, as many infected crew members could have already gone into our community unnoticed and undetected,” said Dr Leung Chi-chiu, chairman of the Hong Kong Medical Association’s advisory committee on communicable diseases.

“Many of them could have used public transport or taxis to get around in the city, spreading the virus further and wider, and it may explain partly why many taxi drivers have got infected.”

He said even though leisure travel had been crippled, cargo ships and flights were largely unaffected in Hong Kong, one of the busiest transport hubs globally, and this was on top of relatively relaxed quarantine rules for crew members.

The health expert said a big loophole in the city’s newly tightened policy for crew members was that only those arriving at the airport had to get tested for Covid-19 at the nearby AsiaWorld-Expo, overlooking others arriving through various ports and terminals.

The now-compulsory test for sea crew members before they leave their port of origin was also not watertight, Leung said, citing a recent case in which 57 sailors in Argentina were found to be infected after 35 days at sea, even though the entire crew tested negative before boarding.

Dr Ho Pak-leung, an infectious disease expert from the University of Hong Kong, also urged the government to tighten exemption measures for sea crew members.

“Vessels that do not have cargo operations should not use Hong Kong to change crew members,” Ho said. “Reducing the amount of inbound sea crew members could save some resources in testing, tracing and health care, and also lower community outbreak risks.”

Data from the Transport and Housing Bureau show that around 11,730 sea crew members have been exempted from quarantine since February, and the city has been allowing unrestricted sea crew change for vessels since June 8. The arrangement means even vessels that do not have cargo operations can enter local waters to rotate their sea crew, who, before July 8 did not need to undergo any quarantine and virus testing in Hong Kong.

According to a maritime trade publication, Hong Kong was described as the only place in Asia that was “truly open” to the change of vessel crew members.

The possible transmission risks brought by sea was raised in late June after nine ship workers, who arrived in Hong Kong from Indonesia, Greece and Croatia, were found by mainland authorities to be infected with Covid-19 when their vessel arrived at Ningbo in eastern China. The group had spent up to three days in Hong Kong before leaving for Ningbo.

The Post also found that in the same period as the incident involving the Ningbo crew, a total of 28 domestic helpers were classified as imported infections, representing 25 per cent of all imported cases. Leung said the figure was worrying as the government only announced on July 7 it would look into asking employers to quarantine workers at hotels, meaning community infection might have already taken place.

The two previously overlooked groups, Leung said, might have sparked off the city’s current third wave. Once the virus gained a hold in the community, experts said, the government had been slow in reacting, and the public was too complacent, which exacerbated the outbreak.

Ho said the belated decision to allow civil servants to work from home sent a wrong signal to the private sector and the community, while Leung believed the daily flow of hundreds of thousands of government workers on public transport provided the hotbed for further transmission.

“Many Filipino and Indonesian maids gather on Sunday, singing and dancing together without masks. Many people smoke together as well,” Ho added. “If citizens don’t behave, then any government measure would only achieve half its intended effect.”

The government, in a statement on Sunday, said the exemption arrangement for certain workers, such as cross-boundary truck drivers, sea and aircrew, was “essential to maintain the necessary operation of society and the economy”.