Saturday, February 4, 2012

Don't tie one on!

A new study in the Journal of Hospital Infection seeks to shed some light on an area of true controversy in infection prevention: whether clothing is involved in the transmission of organisms between providers and patients. The party line thinking in the infection prevention world goes something like this: infrequently laundered white coats and neckties do not transmit pathogens to patients, but if a patient is infected or colonized with MRSA, VRE or MDR-gram negative organisms wear a plastic gown when you enter his room. I have yet to have anyone explain to me the logic behind this paradoxical thinking. In my simple mind, clothing either has the potential to transmit pathogens or it does not. If it does, then minimize that risk. Shedding white coats, ties and long sleeves makes sense to me. The real question, I believe, is not whether infections are reduced by these simple interventions, but to what degree.

In the JHI study, a physician simulated a physical exam on a mannequin. The physician wore 4 different combinations of shirts and neckties (short sleeved shirt, long sleeved shirt, with tie, without tie). Prior to each simulated physical exam, specified areas of the shirts and ties were inoculated with Micrococcus luteus. After the exam, the mannequin was then cultured for the presence of Micrococcus. Each clothing combo experiment was repeated 5 times.

The clothing combo resulting in the highest rate of mannequin contamination was long sleeves + tie (transmission occurred in 4/5 experiments) and lowest with short sleeves sans tie (0/5). Looking at each item separately, long sleeved shirts were associated with more frequent transmission than short sleeved (5/10 vs 2/10), and ties more frequently than no ties (6/10 vs 1/10). Based on the application of a statistical test to the proportions shown above, the investigators concluded that ties increased the risk of transmission of bacteria, but long sleeves did not. Given that there were only 20 experiments I don't think we can draw many conclusions here, except that it's another study which adds to the biologic plausibility that clothing may be involved in transmission of pathogens in the hospital. As a guy who still follows the bare-below-the-elbow approach (i.e., what follows may reflect my bias), I find it intriguing that the only clothing combo in which no transmission occurred was short sleeves + no tie. Aren't we still trying to get to zero?

Photo: Brown Medicine


8 comments:

  1. but what about Bow Ties? (yes, I am serious ... every Endo prof I know wears one on rounds ...)

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  2. I have no problems with bow ties when they're coupled with short sleeves (though kind of a dorkish look, I think) or long sleeves rolled up above the elbows.

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  3. the study should have also had bacteria on his forearms. its not like bacteria only attach to clothes...

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    1. It's reasonable to hope that forearms will be washed between patients. Clearly shirt sleeves will not.

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  4. http://www.readit.me/2013/07/40-maps-that-will-help-you-make-sense.html

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  5. From the Methods section of the paper. "Micrococcus luteus (ATCC) was suspended in sterile saline and adjusted turbidometrically to a concentration of ~1.5X10 8th colony-forming units (cfu)/mL .A Dacron swab was dipped into the bacterial suspension and was rubbed over the terminal 6 cm of the tie for those tests involving the tie and the corresponding location on the front of the shirt for tests involving no tie. The terminal circumferential 2 cm of the cuffed portion of long and short sleeve shirts were inoculated in a similar manner."

    6 cm of tie? How many people are getting that much bacterial contamination on their ties and shirt sleeves? If you are, then you need to reassess your approach to infected patients.

    The only significant difference among all the sites was for ties. It is therefore incorrect to assume that because short sleeve/no tie had no contamination it was somehow proven to be the best way to dress just because you think so.

    Apparently there is no evidence to support the bare below the elbows rule and it may be having some unforeseen consequences. http://www.bmj.com/content/346/bmj.f3211 Here are two quotes from that article. "It could be argued that ditching the white coat and tie for hygiene purposes has had the converse effect, in that the informal attire now gracing our wards has encouraged a less robust view of infection control." And "The dress code for UK doctors was imposed more as a political gesture than as an evidence based strategy likely to reduce infections acquired in hospitals."

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  6. Over the past several years, we have blogged many times on the topic of the potential transmission of pathogens via clothing. In a nutshell, the literature can be summarized as follows: (1) there is conclusive evidence that the patient and the patient's immediate surroundings are contaminated by pathogens; (2) there is conclusive evidence that healthcare worker clothing becomes contaminated by patient and environmental pathogens; (3) there is some in vitro evidence that clothing can transmit pathogens; (4) there is no evidence to date that removing ties and white coats from the clinical environment will reduce healthcare associated infections. In toto then we have biologic plausibility that clothing may transmit pathogens. The issue with ties and white coats, in particular, is the infrequency of laundering. We recently surveyed physicians and found that >20% NEVER wash their white coats. I don't think a randomized controlled trial is needed to tell us that is bad.

    So as I see it, since there is no harm to practicing bare below the elbows, there is a potential benefit, and there is essentially no cost, it seems reasonable to recommend bare below the elbows, and at my institution that's what we have done. We haven't mandated it because we don't have enough evidence for a mandate.

    There is a great essay in JAMA last week on the six dangerous words of EBM--there is no evidence to suggest. It's worth a read and applies directly to this issue. As the author notes, there's no evidence to suggest that looking both ways before crossing the street is better than not looking both ways. It's just plain common sense.

    The guidelines committee of the Society for Healthcare Epidemiology has recently reviewed the literature of clothing contamination and their expert guidance paper is currently in press.

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  7. I agree that a lack of evidence does not necessarily mean something is not worthwhile. But you have ignored the observation made by the microbiologist in the BMJ editorial I cited. She says that bare below the elbows has resulted in scruffy dress by doctors and slovenly personal hygiene. This is what I meant by unforeseen consequences. If someone never washes his white coat, what makes you think he washes his shirt or pants regularly or washes his arms up to the elbow after every patient encounter?

    By the way, don't get me wrong. I like your blog. I particularly enjoyed the post on whether hands need to be washed before donning unsterile gloves, a particular Joint Commission obsession. I never did understand that rule and you have given me some ammunition to refute it. Not that the JC cares about evidence.

    And congratulations on getting over 1000 comments on Reddit. Not bad at all.

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