In Hong Kong, anyone known to have been exposed to the novel coronavirus was dispatched by authorities to a government-run facility to quarantine for two weeks. Recently, officials announced that weeks had passed with no new locally transmitted coronavirus cases.

In South Korea, people with moderate symptoms were ordered to decamp to isolation centers. That country’s response to the virus is hailed as a model for the world.

But even as centralized, out-of-home quarantine and isolation appeared helpful in breaking the chain of transmission in other countries, the United States has remained largely resistant to isolating people in government-run centers away from their homes. And in places where voluntary isolation facilities are available, local officials are finding fewer people taking advantage of them than expected.

Citizens of South Korea, including thousands under coronavirus quarantine, voted April 15 in a legislative election. (The Washington Post)

It’s a reflection, experts said, of cost and conflicting priorities, of cultural norms and mistrust of government. Although great time and effort are being devoted to testing for the virus, treating the ill and tracking those who are exposed, isolation centers have received relatively scant attention. Then there are the associated costs, for government and for people taken out of the workforce.

Americans’ suspicions about government intervention also mean large swaths of the population — especially immigrants and people of color who have been subject to government restrictions in the past — are wary of placing their lives in the hands of local officials.

“We just don’t have enough civic trust, in many different ways, to make that something people are going to let happen with confidence,” said Michael Fine, former director of the Rhode Island Department of Health. “You can see that in people on the right, you can see that from the perspective of people of color, and others.”

Data from Crisis Text Line shows social isolation, unemployment and forced quarantines are having a significant effect on people’s mental health. (The Washington Post)

Because states and cities generally control the nuances of their public health efforts, coordinating an isolation policy on a grand scale is next to impossible. And forcing those who have developed covid-19, the disease caused by the novel coronavirus, to quarantine in government-run facilities could provoke legal challenges and social resistance.

Scholars have expressed concern about the consequences of requiring Americans to enter out-of-home isolation or quarantine centers.

In March, 450 organizations and public health and legal experts published a letter on the American Civil Liberties Union’s website saying mandatory quarantine or isolation measures should be a last resort and steps should be taken to protect people’s civil and economic rights. ACLU spokesman Abdullah Hasan said the organization would support isolation outside the home only if it were voluntary and came with the proper economic and social support systems.

Last week, Harvard’s Edmond J. Safra Center for Ethics published a pandemic recovery road map estimating that 14 percent of infected or exposed people would need somewhere to voluntarily isolate outside their residence because they cannot do so safely at home.

“There is substantial evidence that providing a voluntary option to safely isolate will help to dramatically reduce spread of infection to one’s family and therefore the spread of infection overall,” the report concluded, suggesting that using vacant hotels over 18 months would cost about $4.5 billion. The report also called for about $50 a day in income support for people voluntarily isolating, estimating that 40 percent of those in isolation would need the money to survive. The experts pegged the overall costs of those payments at $30 billion over a year and a half.

As states move to expand testing for the virus and launch efforts to track down people who may have been exposed, they have recognized an uncomfortable truth: Urging people to hunker down at home is not enough to prevent cases of covid-19.

Earlier this month, New York Gov. Andrew M. Cuomo (D) ordered a survey of New York City hospitals to gather information about patients they had treated for covid-19 during a recent three-day period. He expected to hear about front-line medical workers being hospitalized, or about patients whose jobs required regular contact with people throughout the U.S. city hardest hit by the coronavirus.

Cuomo expressed surprise at the results: 66 percent of those who were hospitalized had been staying at home, and just 17 percent were employed.

“They’re not working; they’re not traveling,” Cuomo said at a news conference where he shared the survey’s results. “We were thinking that maybe we were going to find a higher percent of essential employees who were getting sick because they were going to work — that these may be nurses, doctors, transit workers. That’s not the case. They were predominantly at home.”

The disheartening implication of that data is that home isolation is not necessarily offering protection to those participating in it — especially for people in densely populated cities such as New York.

“Some of us tend to think everyone lives in four-bedroom suburban houses. But that’s not the case,” said Eric Toner of the Johns Hopkins Center for Health Security. “But there are an awful lot of people — the same people who disproportionately represent those who are infected — who live in much more densely crowded spaces. They can’t isolate. They don’t have a guest bedroom where they can isolate.”

In an effort to help jurisdictions looking to implement out-of-home isolation, the Federal Emergency Management Agency issued guidance regarding what it called non-congregate shelters.

Unlike overflow hospital facilities established in some cities, isolation centers are not meant to house people needing treatment or medical attention. Instead, they’re designed for people who test positive for the coronavirus or who have been exposed.

Those cities and states that have opened quarantine and isolation facilities — often in hotels — have largely geared them toward emergency workers or homeless people. For the most part, these facilities do not require those staying in them to do so against their will. But almost all of them prohibit coming and going for anyone exposed to or known to be carrying the virus.

“It’s not vacation. You can’t go back and forth,” said Thomas G. Ambrosino, city manager of Chelsea, Mass., which provides hotel rooms for infected people. “But we’re not keeping people against their will. If you say, ‘I don’t want to stay here anymore,’ we’re saying, ‘Okay. But you’re not coming back.’ ”

New York began securing hotel rooms for isolation purposes early on, acknowledging the city’s similarities to many of the densely populated East Asian cities that used isolation to substantial effect. The facilities are open to those who test positive for the virus and have been discharged from the hospital but do not have homes where they feel they can isolate safely. The rooms are offered at no cost for the extent of the required isolation period and can be booked with a referral from a doctor or hospital.

As of Tuesday, more than 5,600 people were staying in those rooms, according to New York City Department of Emergency Management spokesman Omar Bourne. About 5,000 of them were health-care workers who had been exposed to or tested positive for the virus and feared bringing it home to their families. The rest were people who had tested positive but could not isolate safely in their homes.

In Missoula, Mont., which has yet to see the worst of the pandemic, local health and emergency management officials began getting calls about people here and there needing a place to isolate. The western Montana city of about 75,000 has a substantial homeless population, and officials realized that a trickle of requests could soon turn into a flood — particularly once coronavirus-related job losses left more and more people unable to pay for safe housing.

Officials began hunting for a facility that could provide shelter for those without homes. They found a former Sleepy Inn with rooms that opened to the outside, rather than into a long interior hallway — ideal for maximizing isolation. They petitioned FEMA for support and their city council for money, and persuaded local government that the more than $1 million investment was worthwhile — a lengthy process that highlights the obstacles that can hinder officials even after they decide to set up an isolation facility. Missoula officials said they expect 75 percent of their costs will be reimbursed by FEMA, an expectation shared by officials in other jurisdictions that have set up facilities in accordance with FEMA guidelines.

Officials in Louisville partnered with the Salvation Army to make sure homeless people needing isolation had somewhere to go. Relatively few people have used the service.

The same has been true in Las Vegas, which constructed a substantial quarantine and isolation facility for homeless people. Officials said the facility sheltered 130 people and discharged 72 of them in its first three weeks of operation. It was built to house 500, in accordance with surge projections, said Community Services Department Director Kathi Thomas-Gibson.

But Las Vegas has not come close to needing that many beds. Local officials warn that with the city’s signature tourism industry largely shut down, more people may find themselves unable to pay for adequate housing in the weeks to come. Las Vegas, like many cities, could see a rise in homelessness that will make such shelters crucial to limiting outbreaks.

In Chelsea, Mass., a hotel dedicated to people who tested positive for the coronavirus could be a model for communities wanting to make out-of-home isolation more widely available.

The city is sharing the hotel with nearby Revere, Mass., to address the needs of those for whom infection meant they couldn’t isolate safely in high-density housing prevalent in both jurisdictions.

“The situations we were seeing, and knew would be replicated, were situations where a person was getting a positive covid-19 diagnosis, returning home to an apartment where they were subletting a room from other roommates, and their roommates were telling them, ‘Get . . . out of here,’ ” Ambrosino said. “They were sort of out on the streets by themselves without a lot of legal recourse against the subletting situation, which goes on in a lot of these crowded houses.”

In Chelsea, those who feel they cannot isolate safely can call the city’s 311 line to explain their situation or use referrals from medical professionals to secure rooms in the hotel. That information is passed along to medical officials from Massachusetts General Hospital, headquartered in nearby Boston, which volunteered personnel to help oversee intake and monitoring of patients at the isolation facility.

The hotel housed 78 people on its busiest night of the pandemic and 69 on Monday night, somewhat fewer than Ambrosino and his team expected, something he attributes to a variety of factors — including that many of those cast out from crowded living facilities are undocumented immigrants, who fear the consequences of making contact with any government system.

Hillsborough County, Fla., set up two Tampa hotels to house people who might need to isolate, but as of early May, they had not received much use. A hotel in Marietta, Ga., was used for only a few weeks before it was shut down.

Fine, the former Rhode Island health official, said officials should embrace a more proactive approach that would direct people to isolation facilities at their first sign of symptoms, rather than waiting for them to receive a test.

“When I talk to patients, which I’m doing all day long, the first question I ask them is, ‘How many people live in your house and how many bathrooms do you have?’ ” Fine said. “If you live in the ’burbs in a five-bedroom house with four bathrooms and two people living there, they don’t need out-of-home isolation. But if you live in a triple-decker with eight people living in a place with three bedrooms and one bathroom, those people need out-of-home isolation.”