The spread that caterers served at two prep sports banquets last month betrayed no hint of what lurked within.

Athletes from the Totino-Grace football team and the Fridley girls swim team dined on roast beef and rotisserie chicken at the prestigious Edinburgh USA country club.

The next day, the meal bit back. Students called in sick for school, parents couldn’t go to work.

They’d been hit by norovirus, the leading cause of foodborne illness. The likely culprit? Sick food service workers.

Since at least 2006, the Minnesota Health Department has concluded that sick workers were the likely or suspected cause of over 72 percent of all norovirus cases on average each year. “It’s one of the biggest problems in food safety, and arguably the biggest,” said Kirk Smith, head of the state Health Department’s foodborne disease investigation unit.

Restaurants and food service operators are supposed to have strong practices to keep ill employees out of the kitchen. But sometimes, policies aren’t adequate or properly communicated to workers, who often have an economic incentive to work because otherwise they won’t get paid.

“For these policies, it’s one thing to have them, and another thing to implement them,” said Jason Newby, Brooklyn Park’s code enforcement and public health manager. “At the end of the day, it starts with the manager. But the staff needs to tell management when they are sick, too.”

They often don’t. In a study published last month in the Journal of Food Protection, almost 60 percent of food service workers surveyed — including some in Minnesota — said they had worked while ill, mostly without management’s knowledge. Twenty percent of those worked at least once while vomiting or experiencing diarrhea.

High volume, high risk

Norovirus, which is prevalent during the winter, causes vomiting, diarrhea and cramps. Those who get it often don’t seek medical help, but the virus still causes an average of 400,000 U.S. emergency room visits annually, and up to 800 deaths, mostly among the elderly, according to the Centers for Disease Control.

Big norovirus outbreaks tend to happen in high-volume dining settings such as cruise ships, nursing homes, schools and banquet facilities like Edinburgh. “This [Edinburgh] was a case of a lot of contamination all at once,” Smith said.

Lancer Hospitality, Edinburgh’s food service operator, was juggling the two prep sports banquets on Dec. 8, serving almost 350 customers.

Mendota Heights-based Lancer is used to such events, with over 30 years of experience, about $40 million in annual sales and close to 800 employees at multiple locations in Minnesota and Washington state.

But at least 57 people got sick after they attended the Totino-Grace and Fridley banquets, one of the state’s largest norovirus outbreaks in the past seven years, according to the Minnesota Department of Health.

The actual number is likely higher given the limits of state health investigations.

Totino-Grace’s football coach, Jeff Ferguson, told the Star Tribune that at least 75 attendees of his banquet alone fell ill.

It’s not clear what food or foods carried the bug. However, on or near Dec. 8, 13 of Lancer’s Edinburgh workers were showing signs of norovirus, Brooklyn Park health regulators concluded.

“The fact that [Lancer] had that many ill employees and didn’t seem to have implemented a very strong policy is concerning,” said April Bogard, a project manager for foodborne safety regulation at the Minnesota Department of Health.

Lancer has a corporate policy on food safety, covering among other things hand-washing practices and reporting and record-keeping of employee illnesses. But Lancer acknowledged that the communication of its policy at Edinburgh essentially broke down.

Shortly after December’s outbreak, Lancer “made changes in the senior culinary management team” at Edinburgh, including installing a new food chief steeped in safety training, said Glenn Baron, the company’s president. “Obviously this is something we have taken very seriously. Our company depends on our reputation.”

A stubborn bug

Lancer has had one previous outbreak linked to ill workers, also at Edinburgh, in 2007 when 15 guests were sickened with norovirus at a groom’s dinner. The company has held the catering contract at Edinburgh — owned by the city of Brooklyn Park — for 15 years.

Lancer promptly reported the December outbreak to the city and didn’t charge the prep sports teams. Coaches for both Totino-Grace football and Fridley swimming said they’ve been satisfactorily holding banquets for years at Edinburgh and don’t expect the norovirus outbreak to change that.

Foodborne illnesses in Minnesota have fluctuated since 2005. But by far, norovirus is the leading food bug, responsible for 49 of 74 foodborne outbreaks in Minnesota in 2011 and 2012 combined, sickening at least 577 people. Data for 2013 were not available.

Norovirus is particularly hardy, living longer than many viruses and spreading in great quantities. “There’s a reason it’s the most successful food pathogen out there,” said the Health Department’s Smith.

Daube’s Bakery in Rochester learned that the hard way. The popular bakery supplied the cake for a wedding reception at Victoria’s restaurant in Rochester last March.

Twenty-one guests were sickened, according to the Health Department, and an investigation concluded that the likely contamination source was cake icing prepared by a Daube’s employee.

‘An extremely painful event’

“It was terrible — half the people at the wedding got sick,” said Cynthia Daube, the bakery’s owner, who said she’d never had a food-safety problem in 27 years. She noted that none of her own customers or staff got sick but said “it was an extremely painful event for me.”

Brian Prose, general manager of Sunsets, had a similar reaction to a 2013 norovirus outbreak at the Wayzata restaurant, the first in its 25-year history. “It was extremely embarrassing for us. We thought, ‘We’re better than that,’ but it shows you how vulnerable you are.”

The state Health Department found that at least 17 Sunsets patrons got sick, and that “multiple” ill workers likely contributed to the contamination.

At Sunsets, as at Lancer Hospitality, full-time employees get some sort of sick leave.

But part-timers don’t, a common practice in the food service industry, which relies heavily on part-time labor. “The reality is that most food workers don’t get sick time,” said the Health Department’s Bogard.

Plus, their wages are relatively low, with median pay of about $9.20 an hour.

The paycheck factor is big: 49 percent of workers surveyed in the Journal of Food Protection study published in December said “not getting paid” influenced their decision to work while sick.

“Dedication to the job” or “not wanting to leave co-workers short-staffed” were even bigger reasons workers reported for working while ill.

Hand-washing paramount

The study suggested that sick workers are not taking precautions to keep customers from getting ill, including avoiding food preparation and washing their hands more frequently. As simple as it sounds, proper and regular hand-washing can be critical in stopping norovirus outbreaks.

“Every time we see an outbreak, hand-washing had to fail basically,” Smith said. “We as a society don’t wash our hands very well.”

Bogard calls norovirus “a people problem, not really a food problem.”