A discussion as to the best way to handle environmental
contamination by Clostridium difficile can be at times the equivalent of
watching a soap opera. When it comes to
who believes what, who knows best, what is stated in current infection
prevention guidelines, newly published peer reviewed articles and of course
disinfectant manufacturing sales materials highlights the fact that two
seemingly similarly educated people can be complete polar opposites! While I’ve never been involved in a
discussion that has come to fisty-cuffs, I do have two pairs of 16oz boxing
gloves that I’d gladly provide if it would help come to a consensus!
I think with advancement and by this I mean our ability
to manufacture “better” disinfectants, our ability to improve test methods both
for disinfectant product efficacy but also for clinical specimen sampling and
disease diagnosis we become so enlightened with all the “new” stuff we forget
the importance of the basics. I think we
often need to be reminded of the basics.
While there is sufficient published science to support
that sodium hypochlorite at the correct dilution and contact time has the
ability to kill C.diff spores, it has not been until recent years that Health
Canada or the US EPA has approved a method to allow for actual label claims
against C.diff. We can now choose from
sodium hypochlorite, hydrogen peroxide and peracetic acid based formulations
with registered claims against spores.
Certainly, from an infection prevention perspective this has meant advancement
in practices, but in the quest to find products that can KILL we have lost
sight of the importance of physical friction.
More simply put, we have lost sight of the importance of how CLEANING,
how WIPING can and WILL remove spores from the surface.
Let’s be honest, to kill spores we need to increase the
concentration of chemical used. This
increase will result in less than stellar occupational health and safety
profiles for the products that are being used and will also have a direct
impact on the compatibility with the various surfaces the product will be
applied.
The 2010, SHEA-IDSA Guidelines for Clostridium difficile
states “The efficacy of cleaning is critical to the success of decontamination
in general, and thus user acceptability of disinfection regimens is key
issue”. When asked about a product’s
ability to kill, I have always stated that I do not care what a product kills,
if staff will not use the product as designed by the manufacturer, the label
claim is meaningless! Don’t get me wrong,
I am in no way saying that we should not use sporicidal agents in dealing with
C. diff. What I am saying is that we
need to consider more that what the product kills, but look at how effective
the product is at cleaning (thereby removing spores from the surface) and most
importantly, how will the staff that will be using these products daily for
long periods of time respond? A well
implemented infection control program requires that the products we choose are in
fact used!
It was with this that I was quite excited to read a
recently published study by Dr. William Rutala and his research team (ICHE,2012;33:1255-1258). The study compared
the importance of physical removal versus sporicidal inactivation of different
cleaning and disinfection chemistries.
There was what I thought of as several key take home points – or “Ah-Ha”
moments. First, did you know that most
studies have quantitated the level of C. diff spore contamination on surfaces
to be <1Log10? Why then do Health Canada and the US EPA require
manufactures to achieve at least a 6 Log10 reduction against C.diff spores in
order to make a claim. If you didn’t
already know, a 6 log10 reduction implies we are chemically sterilizing the
surface. If we do not have that level of
contamination on surfaces to begin with why do disinfectants need to achieve
such a level of kill? As mentioned
earlier, to obtain sporicidal claims we need to increase the concentration of
chemical used. We are creating
disinfectant products that have increased occupational risks. Perhaps if the test method needed to obtain a
sporicidal surface claim was adjusted to provide a more realistic level of kill
based on actual surface contamination we would have sporicidal products that we
could use on a daily basis without the worry of occupational safety or material
compatibility issues.
Secondly, and to me most importantly, CLEANING
WORKS! The study showed that wiping
environmental surfaces, even with a non-sporicidal agent can eliminate
approximately 3 Log10 of C.difficile spores. Sporicidal agents provided a 3 Log10 to 6 Log10 reduction depending on
formulation and/or application with the most commonly used bleach wipe showing
just under a 4 Log10 reduction.
I’m not saying that we shouldn’t use sporicidal
agents. I’ve worked with enough
facilities in outbreak situation to know they work. However, have we set the bar to high in terms
of what is required with respect to obtaining a registered C. difficile claim? Are we knowingly, exposing our staff to
unnecessarily high concentrations of chemicals when as we know the level of
contamination on surfaces is significantly lower than the level of kill
required to obtain a label claim?
Knowing that cleaning works, would we be wrong to develop protocols that
focus on the physical removal of spores for cleaning of isolation rooms and
utilize sporicidal agents for terminal cleaning, for outbreaks or for use on
wards with higher endemic levels of C. diff?
I know facilities that do just that and do it well.
Food for thought, I hope!
Bugging Off!
Nicole
