Katie Wingfield, 49, was coming to the end of a six-week trip across New Zealand and Australia, but the closure of Hong Kong as a transit hub meant her flight to London via Perth was no longer possible.

There was a “mad scramble to find flights”, the British national said, as Hong Kong and Singapore were both closed to transit – the island nation having closed its borders to short-term visitors on March 22.

Wingfield’s only remaining option was to pay A$19,000 (US$11,380) for two business-class tickets on Qatar Airways to London via Doha, the last major transit hub that is still open. In fact, Qatar Airways has in recent days been adding more flights on top of the 150 daily services it currently operates to get more people home, particularly those living in Australia.

David Flynn, founder of online travel news website Executive Traveller, said: “As more and more airlines reduce flights and in many cases abandon routes, having a major gateway airport suddenly declared off-limits to transit passengers is sheer travel trauma.”

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Cathay Pacific and Singapore Airlines, two major Asian carriers reliant on transfer passengers, have already slashed flight schedules and by next month will operate just 4 per cent of their planned services.

In other virus-stricken countries in the region, including mainland China and South Korea, travel options via major airlines are few and far between. Emirates and Etihad this week grounded all flights, cutting off two connector airports in Dubai and Abu Dhabi.

Hong Kong is the worst-affected airport in terms of the number of flights cut so far, with an 81 per cent reduction in passenger capacity, according to aviation data company OAG. The airport is still the world’s busiest cargo airport, however, and has had more freighter flights than passenger flights over the past week.

The city’s passenger numbers tumbled 68 per cent year-on-year in February, reflecting a regional trend. Passenger volume fell 33 per cent in Singapore over that time frame, while Bangkok and Seoul’s main international airports recorded drops of 31 per cent and 41 per cent respectively.

As Covid-19 first spread across Asia, airports in the region have been more broadly hit – but the rest of the world is likely to catch up, with Europe already having reported an 80 per cent fall in flights across the continent.

Asia has tightened restrictions on travel from the rest of the world amid a fresh wave of imported coronavirus cases from outside the region, particularly from Europe and the United States.

Efforts by Asian carriers to help repatriate stranded residents appeared to have inadvertently backfired, the International Air Transport Association (IATA) said on Tuesday, as people returned to the region seeking safety given the success of efforts to keep the virus in check.

Brian Pearce, IATA’s chief economist, said a glimmer of an Asian-led recovery had taken a hit as a result. “Imported cases from Europe and the Middle East have once again led to a fall in bookings for the Asia-Pacific region and China international – not China domestic,” he said. “[The rise in these cases is] leading to closures, travel restrictions in the Asia-Pacific as well.”

Said Joanna Lu, head of Asia consultancy for aviation information provider Ascend by Cirium: “The industry relies on hubs as they create opportunities for connections, but it also bears the cost of the risk of using hubs when there are disruptions.”

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To date, more than 520,000 cases of Covid-19 have emerged worldwide, and about 24,000 people have died. The virus emerged in China, but the epicentre of the pandemic has now moved to the US.

Despite China’s ongoing recovery from the outbreak, it has closed its borders and is restricting foreign airlines to a single flight each week. Chinese airlines are allowed one route to any specific country, with no more one than one flight per week.