No one should have to go to work while sick. Whether you’re a nurse, a child care provider, a charter school teacher or any other worker, working while sick is bad for you, your family, your colleagues and those you serve.

This is especially true for restaurant workers, who handle the food we eat, and for caregivers and educators, entrusted with the welfare of others, including children.

Nearly 90 percent of restaurant workers reported that they receive no sick days, according to a 2010 survey conducted by the advocacy organization Restaurant Opportunities Centers United. The same survey found that two-thirds of these workers go to work when sick. The effect on public health is tremendous: According to the Centers for Disease Control and Prevention, sick restaurant workers are the cause of more than 3 million cases of food-borne illness each year.

It is not a stretch to say that the lack of paid sick days for these and other workers is a public health crisis. Nationally, more than 45 million U.S. workers do not receive paid sick days.

That’s why I applaud the paid sick leave law passed last year by the City Council that extended this critical benefit to one million New York City workers. Earlier this year, the law was expanded to cover an additional 240,000 workers. Under the law, employers with five or more employees must provide five paid sick days per year for employees to use if they or a close relative falls ill.

But five paid sick days are too few. The only way for workers to ensure that they receive the paid sick days they need is to join together in a union and fight for them.

In nursing, for example, members of the Federation of Nurses/UFT receive on average 12 paid sick days per year. Since most registered nurses belong to labor unions, almost 80 percent nationwide had access to paid sick days in 2013, according to the Bureau of Labor Statistics. The bureau reports that just 62 percent of all nonunion workers received paid sick days in the same year.

However, even unionized nurses who receive paid sick days as part of their contracts risk repercussions if they call in sick. Here in New York City, some of our nurse members’ employers have instituted policies that say nurses may take only two sick days per month and that they will be written up if they take more. The result — nurses coming to work while sick — is bad for the nurses and even worse for the patients, especially those whose immune systems are compromised.

In the health care field, the problem isn’t restricted to nurses. In a 2010 nationwide survey of 537 medical residents conducted by the American Medical Association, 57 percent of the residents said that they had worked while sick.

The difference between unionized and nonunionized workers with respect to sick days holds true in charter schools. Charter teachers represented by the UFT receive around 10 paid sick days per year while those in nonunion schools tend to receive fewer. Increasing the number of paid sick days is one of the first items we attend to when we negotiate a first contract with a new charter school employer.

But even the right of union members to paid sick days has come under attack. We are fortunate that our nurse members have succeeded in their fight to maintain their sick-day benefits despite efforts by some of the hospitals and agencies where they work to erode them. Across the country, however, employers are waging an all-out offensive.

In California, 3,000 nurses in the California Nurses Association were forced to strike nine times in just two years — 2012 and 2013 — to prevent their employer, the health care giant Sutter Health, from eliminating their paid sick days, just one of nearly 200 concessions the company was seeking in contract negotiations.

Paid sick days are not a benefit that we should have to fight for. They are a basic human right, recognized in most industrialized countries but not in the United States. Indeed, the Center for Economic and Policy Research reported in 2009 that the United States alone among the world’s 22 most developed countries does not guarantee that workers receive paid sick days. Our country’s labor laws don’t even protect all workers from being fired if they miss work due to sickness.

As union members and caregivers, it falls to us to fight to change this disastrous state of affairs and see that all workers, union and nonunion alike, are afforded the right to care for themselves and their families in the event of illness.