People shouldn’t work preparing or serving food when they are sick because they may spread the illness. That’s become a food safety mantra, and yet outbreaks are repeatedly traced back to sick food workers – like the 300 who got sick with norovirus at the Haaaaarvard faculty club earlier this year after 14 food service employees were discovered to be working while sick. Or the 529 who got sick with norovirus at Heston Blumenthal’s Fat Duck restaurant last year, where again, the presence of sick food workers was cited as a contributing factor to the outbreak.

There’s a difference between saying what should be done – sick workers stay at home – and actually doing it – food service workers may get fired, whether they work with divas or in dives.

Medical doctors are the same.

The Associated Press reports more than half of doctors in training said in a survey that they’d shown up sick to work, and almost one-third said they’d done it more than once.

Dr. Anupam Jena, a medical resident at Massachusetts General Hospital in Boston, developed food poisoning symptoms halfway through an overnight shift last year, but said he didn’t think he was contagious or that his illness hampered his ability to take care of patients.

Jena, a study co-author, said getting someone else to take over his shift on short notice "was not worth the cost of working while a bit sick." He was not among the survey participants.

The researchers analyzed an anonymous survey of 537 medical residents at 12 hospitals around the country conducted last year by the Accreditation Council for Graduate Medical Education. The response rate was high; the hospitals were not identified.

The results appear in Wednesday’s Journal of the American Medical Association.

Nearly 58 percent of the respondents said they’d worked at least once while sick and 31 percent said they’d worked more than once while sick in the previous year.