There are various discussions going around (e.g. one here at Huffington Post) about a November 2009 paper by White, et al., (abstract here) in the International Journal of Food Microbiology, entitled “Beverages obtained from soda fountain machines in the U.S. contain microorganisms, including coliform bacteria.”

Attorneys might be gearing up to have a field day on this one, given that some big soda companies (e.g. coke) purvey their products through these dispensers. Do these companies bear responsibility for the cleanliness of these devices? Perhaps they at least should be informing the stores that use them that certain practices are expected.

As the authors report,

… coliform bacteria was detected in 48% of the beverages and 20% had a heterotrophic plate count greater than 500 cfu/ml. Statistical analyses revealed no difference in levels of microbial contamination between beverage types or between those dispensed from self-service and personnel-dispensed soda fountains. More than 11% of the beverages analyzed contained Escherichia coli and over 17% contained Chryseobacterium meningosepticum. Other opportunistic pathogenic microorganisms isolated from the beverages included species of Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia.

These findings suggest that soda fountain machines may harbor persistent communities of potentially pathogenic microorganisms which may contribute to episodic gastric distress in the general population and could pose a more significant health risk to immunocompromised individuals. These findings have important public health implications and signal the need for regulations enforcing hygienic practices associated with these beverage dispensers.

Indeed, this matter a basic health department issue. I’d think the manufacturers of these dispensers (and, hopefully, the soda companies who’s products come out of them) have written instructions about maintaining, including disinfecting, these dispensers.

The health departments no doubt have regulations in place about how the lines, tanks, nozzles, etc. of these dispensers are to be disinfected (such as by using a chlorox solution in the right way at appropriate intervals), as well as being prepared to fill a sample bottle once in a while and test it, when they inspect. But is disinfection done at your local pizza shop or restaurant? It is a bit of a pain to do…. my home water/jug dispenser has instructions on disinfecting everything, saying it should be one every six months.