Healthcare Hygiene magazine October 2019 | Page 20

Defining “Clean”
in the Healthcare
Environment:
A Microbial Standard
is a Moving Target
By Kelly M. Pyrek
In
its time, the 2003 Guidelines
for Environmental Infection
Control in Health-Care Facilities was
a good starting point for healthcare
institutions to establish and implement
their cleaning and disinfection protocols
and policies.
Fast-forward to late 2019, and the
guidelines seem quaint and almost an-
tiquated, as the environmental hygiene
research agenda is being pushed and stretched to its limits,
and as investigators pursue key scientific inquiries relating
to surface cleaning and its impact on patient-centered
outcomes and healthcare-acquired infection (HAI) rates.
Carling (2013) summarized much of the current thought
on the role of the environment in HAI prevention: “Over the
past decade, multiple studies have shown that approximately
30 percent to 60 percent of surfaces in the patient zone of
individuals colonized or infected with C. difficile, VRE, or
MRSA are contaminated with these organisms. Although less
widely studied, several reports have confirmed similar rates
of contamination with A baumanii in colonized or infected
patient rooms. Furthermore, several studies have shown
significant environmental contamination with C. difficile,
MRSA, and VRE in rooms of patients not in isolation for
these HAPs, raising the possibility that such contamination is
related to prior room occupants and ineffective disinfection
cleaning practices.”
He continues, “Indeed, multiple studies have now
confirmed that there is an approximately 120 percent
increased risk of a susceptible patient becoming colonized
or infected with a wide range of HAPs if the individual
previously occupying that room was colonized with that
organism. Although not being able to define causality
with respect to transmission because of limitations in study
design, extensive covert studies have uniformly confirmed
that opportunities for improving environmental cleaning
can be identified in many healthcare settings. These studies
took place in a wide range of healthcare settings in which
a systematic evaluation of environmental cleaning was
performed using the same fluorescent marking system.
As a result of the above findings in acute-care hospitals,
as well as pioneering studies in research hospital settings,
a multisite project using identical process improvement
This is the
first article in
a series that
examines how
we define the
concept of
“clean.”
20
interventions based on objective performance feedback of
cleaning thoroughness using a fluorescent marker ‘test soil’
system was performed. Highly significant improvement in
terminal room disinfection cleaning was confirmed in two
large independent groups of hospitals. Several reports have
now shown that improved environmental cleaning decreases
HAP contamination of surfaces. In four comparable clinical
studies objectively evaluating thoroughness of environmental
cleaning over many months, contamination of patient zone
surfaces decreased an average of 64 percent as a result of
an average 80 percent improvement in thoroughness of
disinfection cleaning.”
Carling (2013) adds, “Although the complexity and cost of
studies to evaluate the impact of decreased patient zone HAP
contamination on acquisition has limited such undertakings,
two landmark studies found similar statistically significant
results. The 2006 study by Hayden et al., which confirmed
a 66 percent reduction in VRE acquisition as a result of a
75 percent improvement in thoroughness of environmental
cleaning, as well as the more recent study by Datta et al.,
which found a 50 percent reduction in MRSA acquisition and
a 28 percent in VRE acquisition as a result of an 80 percent
improvement in environmental cleaning, clearly show that
direct patient safety benefits can be realized by improving
the thoroughness of patient zone disinfection cleaning.”
The word “clean” is used quite frequently, but do we truly
understand what that means? How does that translate for
the end user? A globally or even nationally accepted standard
as a definition of “clean” in the healthcare environment
has been elusive.
In 2004, UK microbiologist Stephanie J. Dancer proposed
a microbial standard for what is considered to be “clean”
in healthcare settings – 2.5 CFUs per square cm as an
aerobic colony count; in the subsequent years, the use of
ATP became more common and the value of 100 RLUs was
promulgated by some manufacturers, and the RLU standard
always depended on manufacturers’ recommendations. But
the values weren’t a recognized standard, and variability
persisted.
For example, in a review of the literature pertaining to
background and findings on standards and benchmarks for
the cleaning of high-touch surfaces, Campbell, et al. (2014)
observed, “Visual inspection, the most common, if not only,
evaluation used in the facility industry, was found to be
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