PARIS — With no American visitors to show around the D-Day beaches or the Loire Valley's chateaux, and no work on the immediate horizon, Paris tour guide Linda Zenou frets about how she'll pay off a loan and continue to care for her ailing mother in the achingly lean months ahead. 

"My situation is going to become completely inextricable," she said. "We have nothing to live on." 

In Australia, the government of Queensland, home to the Great Barrier Reef, barred visitors from Sydney starting Saturday because of a growing outbreak in the country's largest city. Queensland tourism official Brett Kapernick predicted the cost for some businesses would be a 40% plunge in revenue.

"With this pandemic, the situation becomes fluid and therefore evolves weekly," Kapernick said. "A week ago, we didn't think we'd be facing a border closed to Sydney."

For growing numbers of businesses and individuals who depend on the global tourism industry, the question is not so much when the coronavirus might take its boot off their throats but whether they'll still be around when business picks up. In trying to fend off the virus, countries that put up entry barriers to tourists have done so at a mounting and terrible cost to themselves and others.

Around the world, travel amid the pandemic is becoming a story of tentative steps forward here, but punishing steps back there, of "yes" to letting back visitors from places faring somewhat better against the coronavirus but not from others where outbreaks are flaring. 

The result is an ever-evolving global mishmash of restrictions and quarantines and zero long-term visibility for businesses trying to make payroll and for everyone from trinket sellers to luxury hotels. 

"It's now survival of the fittest," said Johann Krige, CEO of the Kanonkop wine estate in South Africa, where the drying up of wine-tasting tourists threatens the survival of dozens of wine farms around the historic town of Stellenbosch, near Cape Town.

"A lot of them are going to go under because they just don't have sufficient cash flow," Krige said.

As the Indonesian resort island of Bali tentatively opened to domestic visitors Friday, the beaches of Da Nang, Vietnam, were deserted. The city locked down Tuesday to contain a cluster of nearly 100 cases.

On Portugal's Algarve coast, catastrophe also looms for the staffs of empty hotels, bars and restaurants losing hope that tourists will return quickly enough to keep them afloat. In a region almost entirely reliant on tourism, the unemployment rate has already jumped by 230%.

And in Oxford, England, tour operator Frederick Laurie is clinging to British "stay-cationers," optimistically describing them as "green shoots" in an otherwise bleak year. He concedes that their numbers will never make up for the ruinous plunge in foreign visitors who thronged the university town before the coronavirus chased them away.

"It's an extremely difficult time for us," he says. His decade-old company, Footprints Tours, has seen revenues collapse by 70%.

Losses globally are counted in the billions. Percentage drops in visitor numbers are often double-digits. Tourism income in South Africa was down 98% in May compared with the same month last year, the Tourism Business Council says, and over half a million jobs in its sector are at risk.

Governments in countries heavily reliant on tourism are trying with bailouts to keep businesses afloat. Thailand's Cabinet this week approved three projects together worth more than $700 million for the tourism industry. 

The bright spots, where they exist, are few and far between. Among them: locals who are unable or reluctant to travel are rediscovering attractions where foreign tourists used to jostle for elbow space. 

Animals have South Africa's world-famous wildlife parks largely to themselves because of lockdown rules that barred international tourists and made it illegal for South Africans to travel between provinces for leisure. At the Kruger National Park, lions sleep undisturbed  on the roads and roam around empty lodges.

At the Louvre Museum in Paris, it's now possible to calmly contemplate the works. That's a rare treat for Parisians but a nightmare for tour guides who gathered in protest again this week, dressed in black and wearing masks, to demand more financial help. Zenou, the 60-year-old guide who usually leads groups all over France, was among them.

"My mother with Alzheimer's is under my care, so I have a loan that I'm not longer sure I can pay," she said.