Many of the country’s largest retailers and fast-food chains don’t pay employees when they’re sick ― a policy that could put those workers, their families and the public at risk as the coronavirus sweeps through the U.S.

Workers at Target, Walmart, Kroger, Taco Bell, Subway, Burger King and a slew of other well-known businesses say they don’t get paid sick leave, according to a survey of workers from The Shift Project, a joint research effort from two sociologists at the University of California, Berkeley, and the University of California, San Francisco. The survey was first published in The New York Times editorial pages.

Universal sick leave policy is crucial to reducing the spread of illnesses such as COVID-19, the disease caused by the coronavirus. Public health officials are now urging Americans to stay home if they’re not feeling well and to practice social distancing, at a minimum. But many of these workers, who are working paycheck to paycheck, often in jobs that involve frequent interaction with customers, can’t follow that advice.

And while some restaurants and fast-food outlets are closing up shop in response to the epidemic, at large grocery stores like Target, Kroger and Walmart, hourly workers must face an anxious public eager to stock up on food, toilet paper and hand sanitizer.

“It’s impossible to avoid contact with people while I’m working,” said Brittany Legowski, a 21-year-old Walmart associate in Menomonie, Wisconsin, who recently worked while she had the flu and fears she will contract the coronavirus at work.

The United States stands alone among the most developed economies in the world in offering no paid sick leave guarantee. Congress is now making some efforts to mandate paid sick leave. This weekend, the House of Representatives and the White House made a deal for increasing access to sick leave, among other measures, to combat the spread of the coronavirus — but it leaves out workers at large employers.

It’s very unusual for a fast-food restaurant to offer paid sick [leave]. You can connect the dots there and think about how dangerous that is. Kristin Harknett, sociology professor at the University of California, San Francisco

Across the board, coming to work sick is very common. About half of Americans say they have gone to work sick in the past year, according to a recent HuffPost/YouGov survey.

It’s apparently even more common at large, high-touch retail and fast-food outlets. Sixty percent of the workers in the Shift Project study said they’ve come to work sick, said Kristin Harknett, the sociology professor at the University of California, San Francisco, who conducted the research with Daniel Schneider of the University of California, Berkeley.

The data published in The New York Times was based on surveys in 2018 and 2019 of about 35,000 workers at slightly fewer than 100 big employers, said Harknett. The researchers plan to put out a report expanding on their research in the future.

More than half of the workers surveyed say they can’t take a sick day. Fast-food restaurant workers were the most likely to say they didn’t get paid sick leave, Harknett said.

She and Schneider estimate that more than a half-million McDonald’s workers don’t have access to sick pay; 165,000 workers at Burger King and 95,000 at Dunkin’ Donuts.

“It’s very unusual for a fast-food restaurant to offer paid sick [leave],” Harknett said. “You can connect the dots there and think about how dangerous that is.”

The survey’s findings are a good corollary to data from the Labor Department, which tracks who gets sick leave in the aggregate. While 93% of workers at the top of the income ladder do get paid sick time, only 30% of the lowest-wage earners do, according to 2019 data from the Labor Department.

The workers least likely to have paid sick leave are the ones most likely to be interacting with lots of people — typically, hourly employees in constant contact with the public, serving and preparing food or selling groceries. Only 64% of retail workers get paid sick leave.

Part-time workers are even worse off. More than half do not get paid sick time.

Even if companies have paid sick leave policies on the books, workers may not be able to take sick days in practice. Walmart started offering sick pay to all full- time workers last year, but according to the survey cited in the Times, only 73% of Walmart employees said they can actually take sick days.

Target and Walmart have both announced emergency coronavirus sick leave policies recently, offering expanded leave to those who are diagnosed with COVID-19.

A spokeswoman from Walmart said all associates can earn up to 48 hours of paid sick time if they’re ill, to take care of a family member or for any other reason — including for last-minute emergencies.

“It’s important to keep in mind that we are reporting on what workers report about their access to paid sick, which is different from official company policy,” Harknett said.

With my beat-up immune system, with coronavirus coming around, if I get sick, I lose my job. There’s no way around it. Brittany Legowski, 21-year-old Walmart associate

Some workers may be part-time or new; others might be unaware they’re entitled to paid sick leave. Some companies require documentation from a doctor or health practitioner ― not always easy to access for low-income workers with poor health insurance or none at all.

On the flip side, Harknett said, some workers might luck out and have a manager who gives them paid time off.

Legowski, the Walmart associate, showed up for a shift a few weeks ago even after she was diagnosed with influenza A because she’d already taken a few sick days and didn’t have the option of taking another without being penalized. She believed she’d be fired.

“I had to work through the shift having influenza,” Legowski, who is a member of the group United For Respect, told HuffPost. “So now with my beat-up immune system, with coronavirus coming around, if I get sick, I lose my job. There’s no way around it.”

The Shift Project research found that some workers at large companies did report being able to take paid leave when they’re sick. Most workers at Ikea, Home Depot, Costco and Stop & Shop all said they were able to get paid sick leave, Harknett said, which is a signal to their competitors that this is a policy they might be able to afford.

Still, the matter of Congress forcing companies to offer paid leave is complicated. As the country heads into an economic downturn sparked by the coronavirus, it’s not a great time to force major companies worried about a downturn in revenue to offer paid sick leave.

Legislation that offers businesses a tax credit to do sick leave actually could put workers’ jobs at some companies in danger. For example, some companies might lay off workers in anticipation of a new requirement to give paid sick leave, said Claudia Sahm, director of macroeconomic policy at the Washington Center for Equitable Growth.

“Why do you want to impose a new cost on McDonald’s at the same time their revenue ... is being hit hard by this? Do you think that is good for the low-income people they employ?” former Obama administration economic adviser Jason Furman tweeted recently. “I agree sick leave is important, we should be pushing Congress to pay for it,” he wrote.

That idea is unlikely to get through Congress, at least for now.

“I don’t support U.S. taxpayer money subsidizing corporations to provide benefits to workers that they should already be providing,” House Speaker Nancy Pelosi (D-Calif.), tweeted over the weekend, defending the deal she made with Republicans on sick leave.

Are you a Walmart or Target associate who’s used, or tried to use, emergency coronavirus sick leave? Email: emily.peck@huffpost.com.