If there is one type of co-worker Americans dread coming into contact with above all others, it is the sick co-worker—the one who should be home in bed but showed up at work despite incessant coughing and sneezing, a runny nose and a painful sore throat. Unfortunately, going to work sick is all too common in the United States: a survey released by Wakefield Research earlier this year found that 69% of working Americans don’t take sick days, even when they’re genuinely ill, because they feel they can’t afford to miss even a day of work. That is if they even have paid sick days; many American workers don’t. According to the National Partnership for Women and Families, 40 percent of private-sector workers and 80% of low-wage workers do not receive any paid sick leave.

Between job insecurity, rising housing and healthcare costs, wage stagnation, outsourcing to developing countries and the lack of federal legislation mandating sick leave, too many Americans feel compelled to show up at work sick when they should be home recovering, and their co-workers—and sometimes the public—pay the price when they get sick as well.

Going to work sick is so common in the United States there is even a term for it: presenteeism. And Wakefield isn't the only researcher who has offered troubling data on the subject. Staples, in a 2014 survey, found that 90% of office workers had, at some point, gone to work sick, and the study found that they were only 60% as productive as they were under normal circumstances.

A survey by NSF International found that 20% of Americans never call in sick no matter how bad they feel. According to NSF, 42% of them refuse to use any of their sick days because they are worried about falling behind in their work. In today’s mean-and-lean workplace model, there often aren’t enough co-workers to take on extra work when an employee is home sick.

Some especially disturbing news came from the Center for Research and Public Policy in 2015. In a survey on food workers, CRPP found that 51% of them go to work when they’re sick. But earlier this year, the Chipotle fast-food chain began offering paid sick days and encouraged workers to stay home if they’re sick. That came as the result of a public relations nightmare in which more than 120 people became sick with norovirus after eating at a Chipotle near Boston College and E. coli outbreaks were linked to Chipotle in other parts of the country. With Chipotle stock plummeting, the company began seeing the wisdom in encouraging sick employees to stay home and get well.

The U.S. is among the minority of developed countries that does not mandate sick leave at the federal level, unlike France, Germany and many other European countries. In France, sick leave is linked to social security.

While there is no federal requirement, some states in the U.S. mandate that companies offer employees paid sick leave, including Oregon, California, Massachusetts and Connecticut (none of which are Republican-dominated, so-called right-to-work states). And some cities have mandatory sick days at the local level.

Philadelphia is a city where sick days became mandatory for some companies in 2015: under city law, workers at Philadelphia businesses with 10 or more employees begin accruing an hour of sick time for every 40 hours worked after they’ve been on the job for three months. Companies with fewer than 10 employees don’t have to offer paid sick time, but according to City Councilman William K. Greenlee, the Democrat who pushed for the law, around 200,000 workers in the city have gained sick days because of the requirement.

Although the Philadelphia statute is hardly a radical one and nowhere near as strong as those in Europe, Republicans in the Pennsylvania legislature have been fighting to overturn the law tooth and nail at the state level. Fortunately, Gov. Tom Wolff, a Democrat, has said he will veto any such GOP-sponsored bills.

As long as far-right Republicans control both the U.S. Senate and the U.S. House of Representatives, a federal sick leave law is unlikely. Even if mandatory sick leave became law at the federal level, there is no assurance that workers would actually take any of the sick days they would be entitled to. At a time when America’s working class is being assaulted on every front, it is no wonder so many Americans are afraid to take their sick days even when they are allowed to. The problem is not only that the U.S. doesn’t mandate sick leave nationwide, it is also that even when Americans do have sick days, they are afraid to take them because they don’t want to risk being considered slackers.

In April, over 39,000 Verizon workers went on strike, and the reduction of sick days was one of the many reasons (others ranged from outsourcing of jobs to proposed reductions of health insurance benefits). Verizon, unions complained, is bringing in huge profits, while its full-time workers are expected to make do on less and less. And the many independent contractors who work for Verizon don’t have sick days at all.

The decline of the labor movement is another reason why American workers force themselves to go to work when they’re sick. When unions were at their strongest in the United States—that is, the late 1940s, '50s and '60s—they set very high standards. Sick leave was one of the things unions were vocal about, along with paid vacation time, health insurance, pensions and good wages. In the 1950s, about one-third of the U.S. labor force was unionized; today, only one in 10 U.S. workers belongs to a union (in the private sector, unionization fell to 6.6% in 2012). As unions have declined in the U.S., working conditions for Americans have deteriorated, including access to sick days.

Thanks to the influence of Reaganomics, neoliberalism, trickle-down economics and the erosion of President Franklin D. Roosevelt’s New Deal, the U.S. has some of the worst working conditions in the developed world. Still, presenteeism is not limited to the U.S. by any means. A 2015 survey by Morneau Shepell found that 81% of Canadians had gone to work sick at some point. Canadian workers, according to Morneau Shepell, were concerned about being infected by sick co-workers: 53% saw presenteeism as a serious problem in their workplace.

Back in 2007, CNN.com published an article on presenteeism in the U.S. Deborah Rice, an office manager in New York City, told CNN, “I've been working in the financial industry for several years now and have found, at least in this industry, that just as people are discouraged from taking all the vacation days they have coming, they are also frowned upon for staying out sick.” And that was before the crash of September 2008.

The 2008 recession certainly didn’t make life any easier for sick American workers. According to data from Bloomberg BNA, U.S. workers were using sick days at about half the rate in 2011 as five years earlier in 2006.

In a 2013 article for Inc.com, Suzanne Lucas pointed out that with today’s technology, there is no reason why office workers shouldn’t be allowed to work from home when they’re sick and avoid infecting their co-workers. But too many managers and businesses, Lucas asserted, promote a workplace culture that encourages employees to come in sick.

Some Republicans may argue that sick leave laws are bad for business; in fact, they’re great for business because productivity is higher when employees aren’t being infected by sick co-workers. In an era of economic angst, fighting for mandatory sick leave is an uphill battle. But it’s a battle that's well worth fighting.