SYDNEY, Australia — Tom Hanks had a cold, or so he thought: slight fever, body aches, chills, the usual.
In the United States, those symptoms may not be enough to get tested for the new coronavirus. But he and his wife, Rita Wilson, who also felt sick, weren’t at home — they were in Australia.
Here, testing is free and widely available, thanks to early and coordinated planning for a pandemic. On Thursday, Mr. Hanks said he and his wife had seen the efforts firsthand, as they tested positive for the virus.
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“The Medical Officials have protocols that must be followed,” Mr. Hanks wrote in an announcement he posted on Twitter, choosing capital letters for his new acquaintances. “We Hanks’ will be tested, observed and isolated for as long as public health and safety requires.”
Mr. Hanks is now the public face of a pandemic’s widening reach. What was once a national problem for China, where the virus originated and soon killed thousands, has become an international stress test for public health performance.
Some countries, like the United States, are looking increasingly ill prepared, or, in the case of Italy, fighting to avoid being overwhelmed. Others, like South Korea, moved quickly to test and isolate huge numbers of people and appear to be bringing their outbreaks under control.
In Australia, which has had just 128 confirmed cases, health officials are barely looking up from their spreadsheets, trying to stay calm in a battle where planning ahead and avoiding drama means victory.
Prime Minister Scott Morrison, still bruised from a failure to react quickly to the country’s bush-fire crisis this summer, set an emergency coronavirus plan in motion on Feb. 28.
Rather than play down the risks or promise that the problem would fade in a month or two — as President Trump did — Mr. Morrison was one of the first world leaders to declare that the virus would span the planet.
“We believe the risk of global pandemic is very much upon us,” he said two weeks ago, as cases were just starting to rise quickly outside China. “And, as a result, as a government, we need to take the steps necessary to prepare for such a pandemic.”
That same day, state and territory health ministers met to discuss plans for testing, stockpiling medication and opening special clinics that would keep potential coronavirus patients out of regular emergency rooms. The officials have continued to meet regularly.
“In terms of the amount of time and human hours that have gone into the planning, it’s massive,” said Ian Mackay, a virologist at the University of Queensland who has been involved. “It’s been going on all year, really, and entire lives have gone into just planning and coordinating. It’s been all-consuming.”
Testing has been a priority from the beginning.
Days after China shared the genome of the virus, Australia’s private testing industry — which handles everything from blood tests to stool samples — was mobilized, with the government making tests free through Medicare, the national health care plan.
Public health officials set up a national hotline for people who think they might have the virus. States have set up web pages with locations for coronavirus testing, which has mostly been taking place in hospital wards set apart from regular emergency rooms.
Anyone with symptoms who has traveled through countries with an outbreak of the virus, or who might have come into contact with someone who did or who seems sick, can be tested.
There is even a drive-through clinic in South Australia that will let you stay in your car for a swab, a model also used in South Korea.
In the United States, little if anything about the process has been efficient or convenient. Tests have been slow to arrive across the country, in part because of a manufacturing problem, according to the Centers for Disease Control and Prevention.
Criteria for who should be tested have been widened only recently. At first, the C.D.C. recommended testing only those who had traveled to Wuhan, China, or had contact with a suspected coronavirus case and had a fever or respiratory symptoms.
In late February, the guidelines were relaxed, but a patient still had to be hospitalized to be eligible for a test. Vice President Mike Pence announced on March 3 that the C.D.C. would lift those restrictions, granting tests if a physician ordered them, but doctors were asked to keep certain factors in mind before doing so. And laboratories are still reporting that the demand for testing is greater than the supply.
In Australia, no shortages have been reported. On Thursday, Annastacia Palaszczuk, the premier of Queensland, the state where Mr. Hanks is hospitalized, said there were 27 people confirmed to have the coronavirus there, and in every case, “we know the origin of where they have come from.”
She did not say whether Mr. Hanks and Ms. Wilson had contracted the virus in Australia or brought it from the United States.
Mr. Mackay, the virologist, noted that Ms. Wilson, an actress and singer, had recently performed a concert in Beverly Hills, on a date within the incubation period for the virus. Mr. Hanks is in Australia shooting a film about Elvis Presley with the Australian director Baz Luhrmann; there were reports that at least one other person on the set had tested positive.
Ms. Palaszczuk said everyone who had come into contact with Mr. Hanks and Ms. Wilson would have to self-isolate, and she promised that they would be well treated. They were two of seven new cases reported in Queensland on Thursday, and they are officially listed as being in stable condition at Gold Coast University Hospital, where they are being kept in isolation.
Under the protocols Mr. Hanks referred to on Twitter, doctors and health officials will regularly check on them, whether or not they stay in the hospital after they are cleared for release.
“I’m very confident that we have world-class doctors that are determined to look after them and give them the best possible care,” Ms. Palaszczuk said.
She then added a warning: “What this signals is that this coronavirus can happen to anyone,” she said, adding: “We need the public to be listening to the authorities, listening very closely and adhering.”
Which is exactly what Mr. Hanks and Ms. Wilson seem to be doing: taking direction from Medical Officials.
“They’re not tripping but they’re going through the necessary health precautions, obviously,” their son Chet Hanks said in a message on Instagram. “I don’t think it’s anything to worry about.”
Livia Albeck-Ripka and Isabella Kwai contributed reporting.