Effect Measure

Food vendors: Taking the gloves off

Stories like this really interest me, so a special thanks to Jody Lanard who sent it along. It’s about those gloves they wear while making you a sandwich at the deli or a fast food joint. You know the ones. The disposable plastic kind. Disposable so you can change them often and throw them away. The kind that prevent the hands of the person behind the counter making direct contact with the food. Those gloves.

From the Journal of Food Protection Volume 68, Number 1 p. 187-190, a paper by Lynch et al.:

A study was conducted to determine whether the levels of selected microorganisms differed on foods handled by gloved and bare hands at fast food restaurants. Three hundred seventy-one plain flour tortillas were purchased from fast food restaurants and analyzed for Staphylococcus aureus, Escherichia coli, Klebsiella sp., coliform bacteria, and heterotrophic plate count bacteria. Approximately 46% of the samples were handled by workers wearing gloves compared with 52% of samples with bare hand contact. Coliform bacteria were found in 9.6% of samples handled by gloved workers and 4.4% of samples handled by bare hands, although this difference was not statistically significant. The distribution of heterotrophic plate count bacteria, a general measure of hygiene, was also higher in samples handled by gloved workers in one restaurant chain. The presence of E. coli, Klebsiella sp., and S. aureus was detected in one, two, and eight samples, respectively, and there were no significant differences between samples handled by gloved or bare hands. Neither direct contact of the tortilla with the food preparation surface nor gender of the worker affected the level of any organism tested. The observed tendency of food workers to wear the same pair of gloves for extended periods and complacency might account for the apparent failure of gloves to reduce or prevent bacterial contamination. The results further suggest that glove use might be counterproductive because workers might wash their hands less frequently when gloved. (Abstract)

Here is some speculation on my part. Gloves protect the food when the organism is resident on the operator’s hands, for example, from a sore with Staphylococcus growing on it. One would think that gloves would also protect from contamination by unwashed hands, and maybe they do, but these data don’t show it. But hands are also able to carry pathogens from one source to another, pathogens from raw meat, say, bugs not normally resident on human hands. In those cases, bare hands might be better because they are a biological medium with many natural antimicrobial defenses built in. It is worth noting that some data suggest that H5N1 only lasts minutes on a human hand but for days on an inanimate hard surface in the environment.

This is another case where what makes sense intuitively might not really make much difference or might even be counterproductive. But some advice seems to be pretty good, even though I haven’t followed it. A couple of years ago I read a paper about the food safety practices of street vendors. You know the ones. You’re really hungry and it smells wonderful. When I lived in Manhattan I used to eat at them all the time (of course as Mrs. R. will be quick to point out, I’ve also gotten food poisoning a number of times). There are 4000 with licenses in Manhattan and who knows how many unlicensed ones. So I was especially interested in an article I found in Public Health Reports, “Safety of vendor-prepared foods: evaluation of 10 processing mobile food vendors in Manhattan” by Burt et al. (volume 118, pp 470-476, 2003). What these folks did was hang out around ten different carts and watch them unobtrusively for 20 minutes at a time. More than half the vendors handled the food with bare hands, just under half with bare or gloved hands that were visibly dirty, seven of ten stored cooked meat products at unsafe temperatures on non-heating or non-cooking portions of the cart during the observation period, and in four of ten carts raw foods were handled in ways that allowed them to contaminate prepared food being served. Several instances of bare or gloved hands coming in contact with the server’s mucous membranes with subsequent contact with the food were also seen.

For decades Mrs. R. has been telling me not to buy food from these vendors, advice she got from her mother (which made it suspect in my eyes, of course). And the stuff always looks so good, even better now than it used to. When I lived in Manhattan in the days of yore there wasn’t much variety: hot dogs, chestnuts, pretzels. Now it runs the culinary spectrum that includes curried meat dishes and rice, chowders, middle-eastern kabobs (“cooked” in front of you), various kinds of vegetarian dishes and much more. These foods are prepared and served away from running water, sanitary facilities, proper storage, efficient means of refrigeration and the usual kitchen appliances.If you add to this personnel untrained in proper food hygiene and a municipal inspectorate stretched thin by budget cuts, you have a recipe for numerous small scale disasters. You know the kind. First you’re afraid you’re going to die. Then you’re afraid you won’t.

Sometimes you should listen to your mother-in-law.

Comments

  1. #1 chezjake
    January 25, 2007

    As one who has done a lot of volunteer food service (charity fund raisers and the like), I’ll second your views on gloves. Of course, NY state health code *says* that you should change gloves between handling raw meat and handling prepared foods, but reality tends to get in the way.

    Then there was that big blow up back in the late ’80s where the Public Health people made all food service establishments get rid of wooden cutting boards and replace them with plastic, which ostensibly could be more easily sanitized. It only took a few years for someone to do a study that showed that (mostly oak) wooden boards had natural antibacterial activity, whereas the cuts and scuffs on plastic boards were havens for bacteria.

  2. #2 Lea
    January 25, 2007

    “Sometimes you should listen to your mother-in-law”. And Mrs. R.
    Are we softening in our old-age there revere?!

  3. #3 MattXIV
    January 25, 2007

    One other thing about gloves is that it’s hard to tell when they get small amounts of liquid on them. When I’m doing lab work with reasonably skin-compatable chemicals, I don’t wear gloves so I can tell immediately if I get anything on my hands and wash them before accidentally contaminating additional surfaces in the lab. Similar problems may be occuring with gloves and fluids from raw meat or the insides of eggs in food prep.

  4. #4 revere
    January 25, 2007

    Lea: I hope not. I have a reputation for being pretty soft as it is.

  5. #5 DeLuca
    January 25, 2007

    I am a vendor food junkie and despite the daily warnings of my co-workers, I have not had food poisoning. On the other hand, I have been ill from something I enjoyed at one of our city’s famous high end restaurants. Maybe it’s just luck or perhaps the vendors on Penn’s campus are drop out’s from the section of infectious disease. Or possibly my gut is acclimated to the pathogens….

  6. #6 drcw
    January 26, 2007

    It can be hard to correctly identify the source of food poisoning: some bacteria can take more than a day to cause symptoms. A bad experience at one restaurant might be the result of eating a suspect burger a day or two previously. (This has happened to me.)

  7. #7 revere
    January 26, 2007

    drcw: You are correct. Most food poisoning goes unrecognized. Except for chemical poisonings, scombroid and ciguatera fish poisoning and the pretty common staph enterotoxin (3 – 6 hours typically), most foodborne illness has incubation periods of 12 – 36 hours. By that time you’ve forgotten the fact that you ate a late meal at a pricey restaurant.

  8. #8 Dan
    January 26, 2007

    “It is worth noting that some data suggest that H5N1 only lasts minutes on a human hand but for days on an inanimate hard surface in the environment.”

    Revere, can you provide more on this – or some links? I have been trying to find the latest best guess on this as it is pertinent to my business. This will also largely inform the need for and types of decontamination protocols called for.

  9. #9 revere
    January 26, 2007

    Dan: I’m away from the office at the moment (for a change) but the cite is pretty common in the various pieces written about it. I’ll have to scrounge around for it after the weekend. Anyone else out there have it to hand? I think there is only one study of this, so it is not strong data, but doesn’t seem implausible to me.

  10. #10 Melanie
    January 26, 2007

    Dan: A quick Google of the literature tells me that viral persistence is temperature-dependent and that 2-3 days can be expected on hard surfaces. Look here.

  11. #11 revere
    January 26, 2007

    Dan: Here’s one source: http://www.who.int/water_sanitation_health/emerging/h5n1background.pdf

    See page 10, top of page.

  12. #12 Ana
    January 28, 2007

    Heh, I’d always assumed that those people wore gloves to protect their own hands!

  13. #13 Ground Zero Homeboy
    January 29, 2007

    Part of the point of the gloves, at least here in Cali, is to avoid handling currency and then handling food. Togo’s (a chain sandwich shop which often carries hummus) has a strict discipline where one set of employees makes the food with gloves on and another set handles the money.

    If you’re wiping your nose and handling food, though, gloves won’t help. Maybe a strong UV light below the counter shining on the food might help?

    And what happens to all those plastic gloves?

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