CBS -- This season's flu outbreak is becoming more widespread and even more deadly. For employers and employees alike, that means it's becoming more expensive in terms of lost productivity and health care costs.
The widespread 2017-2018 flu season may cost U.S. employers $9.42 billion, according to a January estimate from outplacement and executive coaching firm Challenger, Gray & Christmas. That's based on workers taking four sick days to recover.
Yet workplace rules, such as requiring employees to get vaccinated, can be tricky for management, said Aaron Holt, a labor and employment lawyer at Cozen O'Connor in Houston. How such requirements are crafted can be important.
Just this month, a hospital in North Carolina settled with Christian and Muslim employees who were fired after refusing to get a flu shot based on their religious beliefs. The hospital agreed to make a "real effort to provide a reasonable religious accommodation," according to a statement from the U.S. Equal Employment Opportunity Commission.
"Employers should be really cautious about having hard and fast rules with regards to a flu vaccine or how sick a person claims to be," attorney Holt said. "Make sure that you're constantly updating your policies."
A company might decide to craft a temporary policy just for the flu season, limiting the amount of sick days it will offer for a specific time period, or decide to use temporary workers if the number of employees with the flu are out, he said.
How your boss responds may depend on where you live. Seven states plus Washington, D.C., require paid sick leave, according to the National Conference of State Legislatures. No federal laws mandate employer-paid sick leave, according to the NCSL.
So it might not be surprising that a 2016 survey from Staples showed 79 percent of employees went to work sick even though they were knowledgeable about the flu and how it's spread. About 58 percent surveyed knew cold and flu viruses can live on a surface for up to three days, according to the survey of 1,500 office workers conducted by Morar Consulting.
To calculate its multibillion dollar cost estimate, Challenger took illnesses for people over 18 from the previous flu seasons, used the current employment-population ratio of 60.1 percent and an average hourly wage of $26.63. The firm then applied those metrics to an estimate of more than 11 million employed adults missing eight-hour shifts to reach its figure.
About 6.3 percent of all American doctor visits were attributed to the flu virus in the week ended Jan. 13, according to the U.S. Centers for Disease Control and Prevention. That's already bigger than other recent outbreaks, in part because this year's illnesses are tied more closely to the H3N2 virus, a particularly nasty bug for which flu vaccines aren't yet as effective as for some other strains.
"We're seeing a very active flu season, and early signs that the season may be severe," Dan Jernigan, director of the influenza division at the CDC told reporters in a recent briefing.
The flu is also more widespread this year than in recent seasons and is already in the top three, based on the CDC's latest method of calculations, according to Bloomberg.
For the week ending Jan. 13, New York City, Puerto Rico and 32 states experienced high influenza-like-illness (known as ILI) activity, data compiled by the CDC shows. Nine states had moderate activity, while just six states and Washington, D.C., had low activity.
Only three states had minimal activity: Delaware, Maine and Montana. Still, that means flu is active in every part of the country. And fewer people seem to be getting their shot for the season. Of the 30 children who have died so far, about 85 percent weren't vaccinated, Reuters reported.
The CDC reminds that the best way to prevent seasonal flu is indeed to get vaccinated every year and take precautions, such as hand-washing and staying home long enough to recover.