Effect Measure

Handshaking and flu

We’re getting down to it. What’s the scientific basis for a lot of advice that’s being given out as if its uncontroversial. Like washing hands. Or shaking hands is the way flu viruses are passed around. From Helen Branswell’s usual superior reporting:

Might we all be a little healthier this cold-and-flu season if we abandoned the handshake culture? With mounting concern about a possible influenza pandemic and growing awareness of the economic costs respiratory ailments exact through absenteeism, some people are wondering precisely that. (Branswell, Canadian Press)

Makes a lot of sense.

Those foreign fingers could be coated with microbes waiting to hitch a ride on your own.

Next stop: the vulnerable mucous membranes in your nose or mouth, or surrounding your eyes. Perfect portals for viral invasion.

“There’s no question a lot of viruses – flu viruses, cold viruses – can be transmitted on hands. No question about it,” says Dr. Andrew Simor, an infectious diseases expert at Toronto’s Sunnybrook Health Sciences Centre.

So it’s plausible it can happen. But does it?

Odd as it may seem, the science on this isn’t well charted. Despite the fact that these viruses predictably inflict illness on a fair slice of the population year after year, scientists aren’t clear what part of spread is attributable to which behaviours.

Does sneezing without covering the mouth spread germs more effectively than sneezing into a hand or sleeve? Is touching a bus pole more of an infection risk than gripping an extended hand? Would wearing gloves all season guarantee a cold-and-flu free winter?

No one knows.

As several experts have observed, countries that don’t shake hands — Japan, for example, where greeting is done by bowing — [correction: the word don’t was omitted here initially] have less respiratory disease. On the other hand, the Japanese environment is different in many ways besides greeting customs. As an argument, it isn’t very persuasive except to say that whatever role handshaking plays, it isn’t overwhelmingly powerful. The strongest argument for refraining from this deeply seated custom, is it probably wouldn’t hurt.

Not the strongest recommendation, but good enough. As long as you don’t get hysterical about other people shaking hands.


  1. #1 floridagirl
    October 24, 2006

    Actually Revere,
    There is evidence that germs are passed through person to person contact. Look at the epidemiological aspect of the spread of pathogens in the hospital environment. Even with proper precautions, there is still a high risk that germs are transmitted through touch.

    Here is the link the the guidelines from the CDC on Hand Hygiene.


    From the CDC guidelines for Hand Hygiene:
    The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings.

    This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231–43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251–69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence.

    New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized.

    Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

  2. #2 revere
    October 24, 2006

    floridagirl: Lots of guidelines and lots of advice. There is no question it can happen and in some cases may happen. The question is whether it is a significant mode of transmission. There is also evidence the virus stays viable on hands for less than five minutes, too, although I don’t know how firm that evidence is. Good hand hygiene won’t hurt unless it becomes obsessive. But how much it will help is open to question.

    Remember, we are talking about eliminating handshaking in the general public, not in health care institutions.

  3. #3 mary in hawaii
    October 24, 2006

    What has happened to us? Are we bored? Have we said it all, one time too many? This latest is just picking at nits and flies, for lack of anything better to do. Face it, if the H5N1 global pandemic strikes, you’d best not be shaking hands in public with anyone, you’d best be staying home eating your canned tuna and hoping no one comes by.
    The above is only pertinent to avoiding regular flu, and since that’s been making the rounds every year for centuries – handshaking or not – there’s no reason to change the societal customs now.

  4. #4 Brian
    October 25, 2006

    Mary, do you think that H5N1 will somehow be more transmissible than regular flu? Because in all likelihood it won’t, given that it is primarily an avian-trophic virus and won’t mutate immediately to be as highly transmissable among humans.

    I think that probably the most efficient method for reducing flu transmission would be to do something that many Asian populations already do: make it a cultural more to have sick people wear masks. Sure, it makes you look silly but hey, half the things we do in our daily lives are like that.

  5. #5 Joe in Australia
    October 25, 2006

    There are lots of good reasons to be careful about hand hygeine although I think flu transmission probably isn’t one of them. The prime means of transmission used by the influenza virus is probably the mechanisms it promotes: sneezing, mucus production, coughing, and making you collapse so that other people come and treat you.

    Incidentally, I was neither trained nor practice in a medical area, nor have I spent much time researching my opinions. They are based on things I think I’ve read compounded with what seems plausible to me. This means that my opinions are unbiased, so they must be true.

  6. #6 kiwi
    October 25, 2006

    Common sense please..most of us have seen “normal” flu epidemics and still gone about our daily lives in a more or less every-day fashion…bad luck to catch it but who expects to die?Who is quite as cavalier about bird-flu? If this devil prevails,I won’t be shaking anyone’s hand.Would you?..scientific “pondering” notwithstanding.

  7. #7 outeast
    October 25, 2006

    They are based on things I think I’ve read compounded with what seems plausible to me. This means that my opinions are unbiased, so they must be true.

    Heh heh! First laugh of the day – thanks Joe!

  8. #8 william
    October 25, 2006

    Washing hands or no, what is killing people in Indonesia, supposedly H5N1, may actually be TB.
    Please go to the above site.

  9. #9 epifreek
    October 25, 2006

    I know we are talking about the spread of influenza here, but there are many pathogens spread by the fecal-oral route and the hands are critical is getting pathogens from feces to the mouth. Hand hygiene is a good thing, even if it is not the most important preventive measure for influenza.

  10. #10 tympanachus
    October 25, 2006

    Sill whippin’ on Ignaz are we or is it just for respiratory infections we have doubts?

    Sometimes I think only simple hygiene and timely intervention to trauma are the sole benefits of medicine. Ethical(?) drugs are certainly a mixed bag (enjoy the side effect of your choice) with the bugs winning again and Big Pharma pushing their own suspicious agenda. Docs don’t seem to feel they’ve done their job unless you leave with a fistful of wonder scripts wondering how you’re gonna make the $50-100 copays.

    I know, “Stop whining and take my meds”

  11. #11 DeLuca
    October 25, 2006

    I guess my obsessive nail biting is totally out of the question. On the other hand, I use only bleach as a cleaning agent and though I’ve no proof, I noted that when my kids were small they had less diarrheal illnesses than most kids. I recommended cleaning the desks with it to our elementary school during a nasty flu season in the 90’s when student absence was very high and our school seemed to recover faster than the others in the district. I am more concerned with hard surfaces that don’t get cleaned properly than I am with handshaking-door handles, counters in public places, public tables, faucets etc. Those are the things that I avoid or wash my hands afer contacting

  12. #12 David
    October 25, 2006

    This is a crossover thought between the ‘Masks’ topic and this ‘Handshaking’ topic, but I wonder if one of the unconsidered (or at least as far as I have observed, undiscussed) benefits of wearing any mask is that they provide a barrier between your nose and mouth and your hands? I always wear a dust mask when I cut the grass and run the weedeater. If you have never done it, try wearing a mask for an hour or two and see how many times you reach up to almost involuntarily scratch your mouth or nose. Also, observe others and notice how often the hands go to the face. Watch people in meetings and notice how they chew on pens and pencils, and then loan it to you. Watch them stick a finger in their mouth after eating to dislodge a piece of food. Or when you don’t see them cough in their hand, pick their nose, scratch their butt and then walk around the corner and shake your hand. I am all for getting rid of handshaking!!!

    Oh, and unless you have some type of shield, the amount of eye rubbing may just negate any small benefit from wearing a mask. Maybe we should all wear gloves too…

  13. #13 mary in hawaii
    October 26, 2006

    If the WHO raises the alert level and/or declares an H5N1 pandemic imminent, I definitely will not be shaking anyone’s hand. But until then, I hate the idea of paranoia preventing me from human contact. What’s an immune system for, for gosh sake? On the other hand, regarding greeting styles, the original reason for handshakes was to show you weren’t carrying a weapon; On the other hand, the Japanese bow was more a sign of respect, while still allowing opportunity for the bower to sneak a sword from behind his back…which I guess is why the other part of this tradition was to keep your head up and eyes on the other person as you bowed. Me, I like hugs. Not so dirty, more comforting.

  14. #14 PhysioProf
    October 27, 2006

    RE: http://medamericaresearch.org

    Anybody whose Web page begins with this sentence has to be a loon:

    “Lawrence Broxmeyer MD is already heralded as today’s single most brilliant and innovative medical investigator by colleagues in the United States and abroad, having already appeared as lead author in The Journal of Infectious Diseases.”

  15. #15 LibraryLady
    November 1, 2006

    Dear All, Just wanted to share what I do in social settings when I have a cold, or sniffles from allergies. First of all if I am really sick, I stay home. If I am completely recovered, but have a lingering cough, or allergies with sneezing, I don’t shake hands or give a social hug to anyone who isn’t in my household and already exposed.

    This is how I get away with it without hurting anyone’s feelings. I carry a tissue in my hand and if someone reaches to shake hands with me, I show my tissue and explain I may have a cold. Everyone I have ever done this with has smiled and said “Thank You”. Then we go on with our conversation. I realize that allergies aren’t contagious, but the sniffling behavior I exhibit is indistinguishable from a cold to the observer. So, to put that observer at ease I explain everything away as a “cold”.

    I hope that this simple, thoughtful gesture of displaying a tissue or kerchief (clean and uncrumpled, of course) will become an acceptable substitute for the expected handshake.

    Library Lady

  16. #16 Calohan
    September 30, 2009

    Time to change the prescription of those stained glasses you’ve been wearing for 40 years.

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