Do people prepare and serve food at restaurants and other forms of food service, while barfing or crapping?

They sure do.

Is that a risk factor for disease transmission?

Depends.

A bunch of U.S. researchers interviewed 491 food workers and their managers (n = 387) in nine states and found that 12 per cent of workers said they had worked while suffering vomiting or diarrhea on two or more shifts in the previous year.

“Factors associated with workers having worked while experiencing vomiting or diarrhea were (i) high volume of meals served, (ii) lack of policies requiring workers to report illness to managers, (iii) lack of on-call workers, (iv) lack of manager experience, and (v) workers of the male gender.”

The researchers acknowledged the study had several limitations – the uselessness of self-reported data, workers that were interviewed were chosen by the boss, not randomly, and not all infectious workers experience symptoms such as vomiting and diarrhea.

What the researchers do not seem to have acknowledged is this: not everyone who works at a restaurant is barfing or crapping because they are infectious or ill; some are just hungover.

Factors associated with food workers working while experiencing vomiting or diarrhea
03.feb.11
Journal of Food Protection®, Volume 74, Number 2, February 2011 , pp. 215-220(6)
Sumner, Steven; Brown, Laura Green; Frick, Roberta; Stone, Carmily; Carpenter, L. Rand; Bushnell, Lisa; Nicholas, Dave; Mack, James; Blade, Henry; Tobin-D'Angelo, Melissa; Everstine, Karen
http://www.ingentaconnect.com/content/iafp/jfp/2011/00000074/00000002/art00006
Abstract:
This study sought to determine the frequency with which food workers said they had worked while experiencing vomiting or diarrhea, and to identify restaurant and worker characteristics associated with this behavior. We conducted interviews with food workers (n = 491) and their managers (n = 387) in the nine states that participate in the Centers for Disease Control and Prevention's Environmental Health Specialists Network. Restaurant and worker characteristics associated with repeatedly working while experiencing vomiting or diarrhea were analyzed via multivariable regression. Fifty-eight (11.9%) workers said they had worked while suffering vomiting or diarrhea on two or more shifts in the previous year. Factors associated with workers having worked while experiencing vomiting or diarrhea were (i) high volume of meals served, (ii) lack of policies requiring workers to report illness to managers, (iii) lack of on-call workers, (iv) lack of manager experience, and (v) workers of the male gender. Our findings suggest that policies that encourage workers to tell managers when they are ill and that help mitigate pressures to work while ill could reduce the number of food workers who work while experiencing vomiting or diarrhea.