A fly swatter is a device with no innate efficacy exhibited by the device itself but whose efficacy resides solely in the skillful hand and decisiveness of the user (loosely regulated pesticidal device). Hand washing efficacy is much like the fly swatter, totally dependent on how well and decisively it is execution by those same hands (food-contact, drug-antimicrobials, & cosmetic-soap regulated territory).
When considering the effectiveness of hand washing and sanitizer use, we need to recognize that human pathogens and opportunistic pathogens, exist in multidimensional continuums in terms of survival, chemical resistance to antimicrobial compounds, and efficacy of hand washing etc. Because each microorganism exists in their own multifaceted conditions for existence and survival, there can be no “one size fits all” approach to control and prevention of disease in respect to hand hygiene.
At one end of the hand washing efficacy continuum are viruses that are harder to remove from hands than bacteria and the even larger parasite cysts and eggs. This is because size matters. The smaller the pathogen, the more easily trapped in the cracks and creases of our epidermis and our stratum corneum. Here we need to realize that aggressive or “good quality hand washing” is more critical in going after viruses as opposed to our usually larger prey, bacteria. Multiple studies indicate that in addition to surfactant action, friction (good old fashioned elbow grease) at the rinsing stage is perhaps the most critical period of hand washing in its ability to dislodge viruses from skin surfaces. That said, you only have so many highly aggressive hand washings (hand washing events) a day to remove viruses before hands begin to dry out and become sore, even when using the gentlest of soaps.
In another continuum of antimicrobial action we have organisms at one end like C. difficile whose spores are entirely resistant to alcohol hand sanitizers (as discussed in the C. diff blog). And indeed, norovirus is not far from C. diff in terms of chemical resistance. To protect hands from these compounds we must rely on use of the proper gloves where appropriate. For norovirus generally considered fairly resistant to chemical sanitizers there is accumulating evidence that efficacy of high tech sanitizers is as good as an average or substandard hand wash. This should be kept in mind when trying to balance skin health with risk reduction and frequent aggressive hand washing has begun to degrade skin barrier function.
Fortunately at the opposite end of the continuum of antimicrobial action are a very large number of microorganisms, bacteria, viruses and fungi that are easily killed by hand sanitizers. Here hand washing while still necessary, is less important when no visible soil is present and hand sanitizers can be relied upon not only to kill these bugs but also provided much needed emollients back to the skin surface. Skin actually becomes healthier the more the latest generation of hand sanitizers are used.
Remember, use of sanitizer in healthcare and food venues was implemented to protect hands from the potentially damaging effects of too frequent hand washing (and drying). We are not always going to know which microbial hazard we are up against.
To get the very most out of hand hygiene, one really has to do a quick analysis of risks being encountered at that particular moment in time. Is there visible soil, what is the nature of the microbial threat, is C. diff likely a concern etc. When patient care is involved hand hygiene protocols should ultimately be driven by principles provided in the WHO 5 Moment guidelines. The tools are in our hands, like the fly swatter, they need to be used with accuracy, speed and authority. Don’t forget to re-nourish your skin with restorative cream in addition to using hand sanitizers, that can’t help but make hand washing even more effective.
About Barry Michaels
Barry Michaels has over 40 years experience in the field of infectious disease investigation, control and prevention. His research work has involved a wide variety of viral, bacterial and fungal pathogens focused on antimicrobial intervention strategies.
Previously having worked as staff microbiologist for Georgia-Pacific Corp for over 14 years, he is now founder and director of B. Michaels Group Inc. a consultant group active in areas of product safety, product development, regulatory affairs and microbiology related to personal hygiene, surface sanitation and glove use in food, healthcare and various other occupational fields.
Considered the "Guru of Hand Washing" he has been cited widely in the popular press as well as published or participated in hundreds articles, abstracts, book chapters, presentations and forums on the subjects of skin care and infection control. When not working he can be found sailing, fishing or kayaking. Learn more about Barry and connect via Email or on Linkedin.