(USA TODAY) -- Rachel Figueroa-Levin, 26, doesn't work outside her home in New York, and yet she's worried that the nasty flu circulating in the city's workplaces is going to make it through her doors, to her 2-year-old daughter, via her office-worker husband.

If it does, she's going to be angry. "If my husband comes home from work sick, I'm going to try to figure out which co-worker infected him and think nasty things about them," says Figueroa-Levin, a blogger and soapmaker.

She has a point. Health experts agree that if you have the flu, you should stay away from work until you are better.

But that can be tough, especially for the 40% of workers in the private sector who don't have paid sick leave, according to the Institute for Women's Policy Research.

"We know that many people are under pressure to go to work," says Andrew Pavia, chief of pediatric infectious diseases at the University of Utah and an influenza adviser for the Infectious Disease Society of America.

Yet Pavia and other experts say there are many good reasons to resist that pressure during this winter's flu epidemic (even if you don't work with Figueroa-Levin's husband). Here are a few:

You feel awful. The flu is not a cold. "The typical case of the flu starts suddenly, and you feel like you were hit by a truck," Pavia says. For adults, he says, the flu often feels "like the worst viral illness you've had in 10 years."

The flu comes with fever, aches, cough, tiredness and sudden onset -- which you can abbreviate and remember as FACTS, says Susan Rehm, an infectious-disease specialist at Cleveland Clinic and medical director of the National Foundation for Infectious Diseases.

"Many people will find they get more work done by going home and recovering than by going in and walking around like a zombie," Pavia adds.

You may get better sooner. "It takes a lot of energy to fight an infection, and resting is one of the ways you can conserve that energy," Rehm says.

Staying home also may give you time to call your doctor in the first day or two of your illness to find out if it makes sense for you to try Tamiflu or Relenza, antiviral medicines that can shorten the duration of flu, according the Centers for Disease Control and Prevention.

You will protect others. There's no easy formula to predict how many other people a sick worker may infect, Pavia says. But you don't need to touch or breathe on someone to infect him. Coughs and sneezes can spread viruses to people 6 feet away, Pavia says. Flu viruses also can survive on surfaces -- such as keyboards, desks and doorknobs -- for up to 24 hours and infect people who touch them, says Neil Schachter, medical director of respiratory care at Mount Sinai Medical Center in New York.

You will be most infectious when you first get sick and OK to return to work 24 hours after your fever breaks -- a signal that your immune system has the upper hand, Schachter says.

It might be a matter of life and death. The flu is a passing illness for most but a killer for a few. You don't have to work in a nursing home, hospital or preschool to worry about someone who might be at high risk. "Really think about who you work with," Pavia says. People with cancer, heart and lung disease and women in late pregnancy are at increased risk for flu complications, he says.

So is anyone older than age 65, and "we don't all retire at 65 anymore," Schachter says.

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