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Paid sick leave has generated huge attention over the past week as more cases of coronavirus are diagnosed in the US.

But 25% of American workers - or 32 million people - don't have access to paid sick leave from their employers.

The lack of sick pay in the US increases the odds that people will work sick since they can't afford to take home a smaller paycheck.

Eighteen states have laws barring local governments from enacting paid sick leave policies, per the Economic Policy Institute.

A 2018 study found that cities that had required employers to pay workers while they were ill experienced a 40% drop in infection rates a year later.

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The issue of paid sick leave has generated a huge amount of attention over the past week as the coronavirus continues spreading in the US with new cases diagnosed daily. Among measures the Centers for Disease Control and Prevention has recommended is staying home if you're sick.

But that may be a luxury many people can't afford, given that around a quarter of all American workers have no paid sick days, data from the Bureau of Labor Statistics shows. It comes out to an estimated 32 million people.

Around 18 states also have laws barring local governments from enacting paid sick leave, according to the left-leaning Economic Policy Institute, as illustrated in its map below.

Here are the state govts that have prohibited local govts from enacting paid sick days/paid leave policies. Without paid leave, workers must either go without pay or go to work sick and delay medical treatment for themselves or their families. https://t.co/PK0MEYdFrr #coronavirus pic.twitter.com/B2ROB4P4b4 — Economic Policy Institute (@EconomicPolicy) March 3, 2020

On February 25, Democratic Rep. Alexandria Ocasio-Cortez pointed out that low-wage workers, particularly in the fast-food sector, often head to work sick because they can't afford to miss out on any wages.

"I can't tell you how many times the people who handle your food - who are already overworked & underpaid - show up sick to work because our country refuses to guarantee healthcare or paid sick leave," the New York congresswoman tweeted.

Data from the CDC backed up her assessment: One in five service workers reported going to work sick with vomiting or diarrhea.

The US is among the few developed nations that don't mandate that employers pay workers when they fall ill and miss a day of work. It raises the prospect that people - particularly in low-wage jobs - will end up spreading the virus among their coworkers or others in public spaces because they can't afford to take home a smaller paycheck.

"The CDC released very clear instructions to help prevent the spread of respiratory diseases, including staying home when you are sick," senior economist Elise Gould wrote in a blog post for the EPI. "Not everyone has that option."

Federal law mandates only that hourly workers get paid for the time they work. A dozen states require employers to provide paid sick leave for their workers, often including those in part-time jobs.

As of Wednesday, the coronavirus has infected more than 94,000 people in at least 80 countries beyond China, its point of origin. The death toll from the respiratory disease it causes, COVID-19, has killed more than 3,200 people, mostly in China. There are at least 128 confirmed cases in the US.

The disparity is stark between the highest-paid and lowest-paid workers on access to paid sick leave. The same BLS data also shows that within the top 25% in wage distribution among workers, around 92% will get paid while they are sick. That's in comparison to just over half (or 51%) of workers in the bottom 25%.

Some of the 18 states banning cities from passing their own sick pay policies have large populations of workers. Florida is the biggest on the list. Others include Georgia, Alabama, Oklahoma, Wisconsin, North Carolina, and South Carolina.

That would be a significant hurdle for local governments attempting to respond to a public-health emergency like the coronavirus.

Five states do guarantee sick pay, per the EPI, but don't allow county or city governments to implement policies that are different from state standards. Among them are New Jersey, Rhode Island, Maine, Maryland, and Oregon.

There are already indications of what can happen when paid sick leave becomes a reality for people. A 2018 study from researchers Stefan Pichler and Nicolas Robert Ziebarth offered striking insight into the effect of sick pay on slowing the spread of illnesses.

In the 2000s, some of the nation's largest cities like San Francisco, Seattle, and New York City implemented such policies - and Pichler and Ziebarth sought to understand how that affected influenza rates before and after sick pay was enacted.

They found that a year after cities had implemented paid sick leave, infection rates were 40% lower compared to those that had no similar law on the books.

As the federal government attempts to contain the outbreak of coronavirus in the US, the issue of paid sick leave will only gain urgency.