Food Protection Trends - May/June 2020 - 148

ments (5). Previously, bacterial contamination on single-user TMDs in community settings have been evaluated (1, 4).
Egert et al. investigated the microbial contamination
of single-user TMDs at a German university (5). Using
contact agar plates, the authors sampled 20 TMDs and
reported that all of them were contaminated with less than 2
log10 bacteria per cm2. In another study, in which researchers
sampled single-user TMDs in a community setting for
bacterial contamination (4), the authors reported that 145
of 192 TMDs had minimal contamination (1 to 5 CFU),
while 23 (13.1%) and eight (4.5%) of the TMDs sampled
had 'moderate' (6 to 10 CFU) and 'heavy' contamination
(> 15 CFU) of microorganisms, respectively. These two
studies demonstrate the potential for single-user TMDs
to serve as vehicles of pathogen transmission outside of
clinical settings.
Because of the potential public health risks related
to contaminated TMDs, investigations on cleaning
and disinfection practices have also been conducted.
Akinyemi et al. split volunteers into four categories on
the basis of occupation before testing their TMDs for
bacterial contamination (1). The authors found that 92%
of TMDs from the group of marketers/food vendors were
contaminated with bacteria, whereas only 42% of TMDs
from the group of hospital workers were contaminated.
Additionally, TMDs of public servants and lecturer/
students were found to have contamination rates of
39% and 73%, respectively. Akinyemi and co-authors
speculated that the difference in the prevalence of bacterial
contamination could have been due to the disinfection
practices utilized by hospital workers (1). In turn, questions
on the sanitation habits of food vendors and food service
employees were raised, and data from the subsequent
studies show the potential for cross-contamination via
TMDs in the food industry, potentially contributing to the
incidence of foodborne illness.
Other studies have examined at the efficacy of popular
disinfecting products. Howell et al. contaminated iPads
(Apple, Cupertino, CA) with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, and Clostridium difficile in order to compare different
disinfectant methods with wiping with a plain, lint-free
cloth (9). The data indicated that Sanigen 2% chlorhexidine
gluconate wipes (70% alcohol and 2% chlorhexidine) and
Clorox wipes (alcohol and alkyl dimethyl benzyl ammonium chloride-based) were significantly more effective than
the plain cloth in reducing bacteria on iPads. Additionally,
White et al. reported that alcohol-based wipes resulted in
a 2.3 log reduction on the back of the iPad and a 3.3 log reduction on the front surface. Both of these studies highlight
simple and effective means of decontaminating touchscreen
devices that can be utilized by anyone (19).
On the basis of these and similar studies investigating
bacterial contamination of TMDs, the present study was

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Food Protection Trends May/June

designed to determine the levels of microbial contamination
on single-user TMDs and to compare the efficacy of two
cleaning methods for reduction of bacteria. We also aimed
to identify, by means of a survey of participants, potential
risk factors related to the use and cleaning of TMDs as well
as opinions on risks associated with TMD use in general
and within food service establishments. The combination
of the two objectives present a novel approach to further
understanding the risks related to microbial contamination
of TMDs.
MATERIALS AND METHODS
Study design
One hundred university students, faculty, and staff were
recruited to participate in this study. All were required to
have a single-user TMD. University of Arkansas Institutional
Review Board approval (Protocol 17-06-753) was received
prior to study commencement. The study was conducted
during August 2017. Participants were assigned to alternate
treatment groups based on recruitment order-Treatment 1,
Treatment 2, Treatment 1, etc.
Survey
All participants completed a short survey prior to TMD
sampling. The survey was completed on an iPad, using
Qualtrics web-based survey software (Qualtrics, Provo,
UT). Participants were given an ID number that they
were required to enter before starting the survey, in order
to protect their confidentiality. The survey consisted of
questions on basic demographic information, participants'
TMD cleaning habits, and their opinions on the risks
associated with TMD contamination in general and within
retail food service establishments. The construct related
to participant opinions on TMD contamination risks was
measured by a five-point Likert scale (1 = definitely not,
5 = definitely yes).
Sampling TMDs
The dimensions of each participant's TMD were measured
in centimeters, and the presence or absence of a protective
case and screen protector was noted. When a protective
case and/or screen protector were present, they remained
on the TMD during sampling, as these are not removed by
the participant during daily use. The TMD was then divided
in half vertically to distinguish side A and side B prior to
swabbing (Fig. 1). Side A represents the non-treated side
(front and back surface) of the TMD, and side B represents
the treatment side (front and back surface). Treatment 1 was
a dry microfiber wipe (Kimtech, Roswell, GA) and treatment 2 was a pre-moistened isopropyl alcohol (IA) wipe
(CareTouch, Future Diagnostics LLC, Brooklyn, NY). Fifty
participants were in the treatment 1 group, and 50 were in the
treatment 2 group.

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