Healthcare Hygiene magazine January 2020 | Page 19

cover story
Contaminated Fomites
& the Contribution
to HAI-Transmission
Dynamics
By Kelly M. Pyrek
It has been
demonstrated
that items such as
medical equipment
and surfaces
are frequently
contaminated
and can serve
as a reservoir
for multidrug-
resistant
organisms
(MDROs) such
as methicillin-
resistant
Staphylococcus
aureus (MRSA),
vancomycin-
resistant
enterococci (VRE),
and Clostridium
difficile.
F
omites flying under the radar is common
in the fast-paced, demanding healthcare
environment and constitute a challenge for the
professionals who are tasked with cleaning and
disinfecting them.
“Each institution and sometimes each unit has
a different way of cleaning things,” acknowledges
Mark E. Rupp, MD, professor and chief of the
Division of Infectious Diseases, and medical
director of the Department of Infection Control
& Epidemiology at the University of Nebraska
Medical Center. “Oftentimes it takes someone
going in and taking inventory of objects in the
room and establishing who is cleaning what.”
Rupp adds, “Point-of-care ultrasound is
our current project. However, there are lots of
items – all the things that are touched frequently
are worrisome – keyboards, phones, everything
near the patient – switches, buttons, handles, etc.
Stethoscopes are another item that healthcare
workers carry around and are rarely cleaned
between patients. In many instances, anything
that is electronic is not cleaned by environmental
services (EVS) – the patient-care staff think that
EVS is cleaning screens and monitors and pumps,
etc. EVS workers are concerned that they will
damage the equipment, or, for daily clean, that
they will set off an alarm or turn off a pump, etc.
Thus, in too many instances, no one is cleaning
the items because people want to believe that
someone else is doing the cleaning.” (See related
article on page 16 of this issue.)
As we know, a fomite, defined as “an
inanimate object that can be the vehicle for
transmission of an infectious agent,” and
includes patient-care items and environmental
surfaces. Kanamori, et al. (2017) remind us that,
“It has been demonstrated that items such as
medical equipment and surfaces are frequently
www.healthcarehygienemagazine.com • january 2020
contaminated and can serve as a reservoir for
multidrug-resistant organisms (MDROs) such
as methicillin-resistant Staphylococcus aureus
(MRSA), vancomycin-resistant enterococci (VRE),
and Clostridium difficile. Transmission of MDROs
from contaminated devices or surfaces to a patient
may occur via direct contact, indirectly via the
hands/gloves of healthcare personnel, or less
commonly via aerosols, water, or food.”
How fomites become contaminated and
contribute to transmission dynamics is a key
factor in improving environmental hygiene in
healthcare institutions. To this end, Xiao, et
al. (2019) developed a model to simulate the
dynamic transmission of MRSA among fomites
in a general medical ward, as well as conducted
network analyses to better understand the
contact relationship between patients’ hands and
environmental surfaces. They also investigated the
effectiveness of applying different levels of two
interventions to seven types of surfaces and utilized
the MRSA distribution patterns and network
analyses to account for the findings. They report
that frequent surface cleaning and antimicrobial
surfaces had larger impacts on MRSA exposures
when applied to surfaces around the index and
the adjacent patients and to public surfaces in
the ward than when applied to surfaces around
other susceptible patients in the ward.
Specifically, to better understand how different
surfaces work in fomite-related transmission,
the researchers modeled the structure of the
relationships between human hands and environ-
mental surfaces as a network; they explain that,
“The multiple environmental surfaces in indoor
environments are not independent but are linked
by hands through human touching behaviors,
thus constructing a surface touch network. In this
network, a node denotes a surface, and an edge
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