Hand washing ineffective, gloves must be used

IPs at meeting ‘discomforted’ by findings

A recently published study by investigators led by Clostridium difficile expert Dale Gerding, MD, found that soap and water hand washing — widely recommended to remove the spore-forming pathogen — is surprisingly ineffective.

In the study, the only solutions found even partially effective against C. diff (greater than one log spore reduction) were a heavy-duty Borax brand name product, an industrial solution designed to remove printer’s ink, and something with the abrasive-sounding name of peracetic acid/surfactant prototype.1

“Many of these products are experimental and were provided to us and we tested them on volunteers in the lab who had spores on their hands,” said Gerding, associate chief of staff for research at the Hines VA Hospital and professor of medicine at Loyola University of Chicago. “But most of these things are not going to be used in health care environments because of their harshness.”

Gerding’s research group had previously found that the alcohol hand rub solutions in mounted wall dispensers throughout the nation’s hospitals do even less to remove C. diff spores.2 In that study, a variety of alcohol hand cleaning solutions – which are highly effective against vegetative bacteria like MRSA — were used by volunteers whose hands had been inoculated with C. diff spores. So many residual C. diff spores remained on the volunteers’hands that they could be easily transferred by a simple handshake with another person. A mean of 30% of the residual C. diff spores were transferred by a handshake. Still, the study found hand washing with soap and water was significantly more effective at removing C. diff spores from the hands of volunteers than alcohol rubs. Though soap and water is preferable to alcohol, Gerding’s latest study showed soap washes still leave a lot of spores and a lot to be desired.

“If you are looking for something to wash your hands with there are an awful lot of things that are no better than tap water, including chlorhexidine, non-antimicrobial hand washes, a 0.5% bleach surfactant prototype,” Gerding said recently in Baltimore at a recent C. diff meeting held by the Association for Professionals in Infection Control and Epidemiology (APIC). “The log reduction is generally less than one log, so if you have 1000 spores on your hands, you’re still going to have probably 10% of those left even after you wash your hands”

The 2004 emergence of epidemic C. diff in the U.S. followed the CDC’s landmark switch from traditional soap and water to alcohol based hand hygiene in hospitals in 2002 guidelines.3 Although alcohol is ineffective against C. diff, many hospitals facing the emerging pathogen had largely moved from soap to alcohol hand rubs for most patient encounters. The CDC subsequently endorsed the 2008 compendium guidelines by the leading infection control groups, which state than in an outbreak situation or in dealing with continuing C. diff transmission health care workers should “perform hand hygiene with soap and water preferentially, instead of alcohol hand hygiene products.”4

Don’t shoot the messenger

While known C. diff patients should be placed in contact isolation requiring the use of gloves by health care workers, the new study raises questions about contaminating hands during glove donning and removal as well as situations where ungloved workers may touch contaminated surfaces and fomites.

“To me it just comes back to gloves, which have been shown – at least in outbreak situations or for high endemic [levels] – to do something to C. diff rates,” said L. Clifford McDonald, MD, FACP, a leading C. diff expert at the Centers for Disease Control and Prevention. “I am not aware of any study that has shown in any outbreak that switching from alcohol gel to soap and water did anything to C. diff rates.”

The news was not exactly well received. Hand hygiene is both the first trench and the last ditch when it comes to infection control, the one measure that the field has come to rely on for break-downs in other areas. When a moderator told McDonald that some of the IPs in the APIC audience were “discomforted” by the findings, he quickly noted it wasn’t his study — implying that if you are going to shoot the messenger at least aim at the right one.

“The [Gerding] study basically says to get any better than tap water you need to use Borax or printers ink or peracetic acid,” McDonald said. “I mean that’s what the data says. So it just gets back to this issue of gloves being the first and foremost [measure].”

McDonald said he is aware of other data that show a more favorable two log spore reduction with soap and water, but that still falls far short of the desired four log reduction (kill rates approaching 99.99%) achieved by alcohol hand rubs against common hospital bacterial pathogens like MRSA and VRE. And since the use of alcohol hand rubs generally increases compliance, the CDC is reluctant to undercut its current recommendations by revisiting the C. diff conundrum.

“We know that alcohol gel does work at reducing [other] infections,” he said. “There is observational data where we moved from soap and water – and all the compliance problems with that – to alcohol gel and saw this bump in compliance and saw infection rates come down. That has happened over and over again with the vegetative bacteria.”

As a result, it seems to make more sense to encourage glove use with C. diff rather than get sidetracked with any more hand hygiene efficacy studies, he added.

“The other thing is do we really think that there is that much contamination on the hands after the removal of gloves?,” McDonald said. “If this is the best data we have for log reductions, should we even go out and do a big hand washing study when we already know that gloves work? Maybe in the right context, but I would rather see us develop some new hand hygiene methods that work on spores first – something that gets closer to a four log reduction.”

References

  1. Edmunds SI, Zapka C, Kaspar D, et al. Effectiveness of hand hygiene for removal of Clostridium difficle spores from hands. Infect Control Hosp Epi 2013; 34:302-305.
  2. Jabbar U, Leischner J, Kasper D, et al. Effectiveness of alcohol-based hand rubs for removal of Clostridium difficile spores from hands. Infect Control Hosp Epidemiol. 2010;31(6):565-70.
  3. Centers for Disease Control and Prevention. Guideline for Hand Hygiene in Health-Care Settings: Recommendation of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force. MMWR 2002;51:No.RR-16:1—56.
  4. Society for Healthcare Epidemiology of America. Infectious Disease Society of America. Compendium of Strategies to Prevent Healthcare Associated Infections in Acute Care Hospitals. Infect Control Hosp Epidemiol 2008;29:S81-S92.