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RESEARCH NOTES
Bacterial colonization on writing pens
touched by healthcare professionals and
hospitalized patients with and without
cleaning the pen with alcohol-based hand
sanitizing agent
K. Halton1, V. Arora1, V. Singh1, S. S. Ghantoji2,
D. N. Shah1 and K. W. Garey1,2
1) Department of Clinical Sciences and Administration, University of
Houston College of Pharmacy and 2) St Luke’s Episcopal Hospital,
Houston, TX, USA
Abstract
This prospective study examined bacterial colonization on writing pens touched by healthcare professionals and hospitalized
patients with and without cleaning the pen with alcohol-based
hand sanitizing agent after each patient visit. A significant reduction in potential healthcare-associated pathogens, especially
Gram-positive cocci, was observed in the intervention group.
Keywords: fomites, healthcare-associated pathogens, infection
control, pens
Original Submission: 14 October 2010; Revised Submission:
16 December 2010; Accepted: 13 January 2011
Editor: D. Raoult
Article published online: 15 February 2011
Clin Microbiol Infect 2011; 17: 868–869
10.1111/j.1469-0691.2011.03494.x
Corresponding author: Kevin W. Garey, Department of Clinical
Sciences and Administration, University of Houston College of
Pharmacy, 1441 Moursund Street, Houston, TX, USA
E-mail: [email protected]
Healthcare-associated infections (HAI) cost an estimated
28.4–33.8 billion dollars in the US [1]. Health personnel are
trained in hand washing procedures, but fomites such as
writing pens, may be carried over several days without disinfection, making them potential carriers of infectious agents.
INFECTIOUS DISEASES
Bacterial organisms have been isolated from nosocomial environmental surfaces, including keyboards, telephones and
doorknobs [2,3]. Writing pens may be potential carriers for
transmission of healthcare-associated pathogens. The purpose of this study was to assess the potential of writing pens
as a source of transmission of healthcare-associated pathogens, which will be important for hospital infection control
practices.
This was a prospective study investigating the potential of
writing pens as a fomite for hospital-acquired pathogens.
Clinical investigators enrolling patients into a study investigating antibiotic-associated diarrhoea during August–September
2009 were given a new writing pen each day. Investigators
were randomly assigned each day to clean the pen between
patient visits with alcohol-based hand sanitizing agent (intervention group) while the non-intervention group did not use
the hand sanitizing agent to clean the pens. Investigators
were instructed to follow strict hand hygiene washing with
soap and water regardless of group assignment. After using
the pen for the entire day to enroll patients, the investigators put the pen in a sterile labelled bag. Pens were then
immediately transported to the laboratory.
Specimens were extracted using a nutrient broth media,
according to the ASTM International standard E1837-96
(standard test method to determine efficacy of disinfection
processes for reusable medical devices). Briefly, each sterile
bag containing 10 mL of media and the pen were sonicated
for 7 min. Following sonication, 0.5 mL aliquots were plated
onto agar plates and incubated for 48–72 h. Colony morphology, Gram staining, motility and biochemical characterization were carried out for presumptive identification of
common hospital-associated pathogens to genus level for
Staphylococcus spp., Enterococcus spp., Pseudomonas aeruginosa,
Clostridium difficile and members of Family Enterobacteriaceae.
Four unused writing pens were used as controls to assure
that pens were not previously contaminated with microorganisms. The proportions of pens with specific organisms in
the control and intervention groups were compared using
the Fisher’s exact test.
Twenty-three pens were sampled (intervention group, 10;
non-intervention group, 13). Two to eleven patients touched
each pen, along with the assigned investigator (median 5), and
did not differ between groups. In the non-intervention group
12/13 pens showed bacterial growth compared with 4/10
pens in the intervention group (p 0.019; Table 1). No growth
was observed on control pens. Pens in the intervention group
were usable for the entire day despite being repeatedly
cleaned with alcohol-based sanitizing agent. An average of
370 colony forming units (CFU)/culture plate was found on
non-intervention pens and a median of 130 CFU/culture plate
ª2011 The Authors
Clinical Microbiology and Infection ª2011 European Society of Clinical Microbiology and Infectious Diseases
Research Notes
CMI
869
TABLE 1. Bacteriological profile from pens used in non-intervention and intervention (wiping with alcohol-based sanitizer)
groups of the study
Total pens with growth
Median colony forming units/plate
Pens with catalase-positive Gram-positive cocci in irregular clusters (presumptively staphylococci)
Pens with catalase-negative Gram-positive cocci in short chains (presumptively enterococci)
Pens with catalase-positive Gram-positive cocci in quartets or octets (presumptively micrococci)
Pens with oxidase-negative, non-motile, Gram-negative cocco bacilli organisms (presumptively acinetobacters)
Pens with yeast (presumptively Candida spp)
Pens with aerobic spore bearers (airborne contaminants)
were found on intervention pens. Skin commensals, presumptively Micrococcus spp., were the most commonly found bacteria (11/23). No Gram-negative bacilli, such as Pseudomonas
or Family Enterobacteriaceae such as E. coli, were identified in
either group. There was a significant difference in the Grampositive cocci presumptively identified as Staphylococcus spp.
and Enterococcus spp. in the intervention compared with the
non-intervention group (p <0.05).
In this study, we incorporated an intervention group that
wiped the pens with alcohol-based sanitizing agent between
patient visits and compared the organism load and bacteriological profile with the non-intervention group. Wiping with
alcohol-based sanitizing agent significantly reduced the number of pens that showed visible growth on culture and
reduced Gram-positive cocci, both Staphylococcus and Enterococcus spp. This is an important finding indicating that the
risk of transmission of healthcare-associated pathogens can
be decreased with the use of a alcohol-based sanitizing agent
for wiping fomites such as writing pens between patients.
S. aureus has been demonstrated to survive on different pen
types, with the longest survival time being 48 h for pens with
a rubber grip [4]. The ability of bacteria to survive on pens
for long durations of time emphasizes the need to clean
equipment (i.e. pens) after patient contact with alcohol-based
sanitizing agent.
There were some limitations of this study. The sample
size was small, which may have resulted in lack of detection
of difference (e.g. in yeasts). The pens were changed after
1 day of use. Increased bacteria load may be present on pens
used for longer periods of time. Species identification and
susceptibility typing were not carried out, which could have
provided specific information on prevention of transmission
of multidrug-resistant organisms. Finally, we did not detect
the presence of Clostridium difficile, which may have been
Non-intervention
Intervention
p-value
12/13
370
5/13
5/13
8/13
4/13
3/13
1/13
4/10
130
0/10
0/10
3/10
1/10
1/10
1/10
0.019
0.090
0.046
0.046
0.214
0.339
0.604
1.000
present in this study of hospitalized patients at risk of antibiotic-associated diarrhoea.
To conclude, pens may be potential fomites for healthcareassociated pathogens. The risk of transmission of fomites,
especially Gram-positive cocci, may be reduced by using alcohol-based sanitizing agents for wiping pens between patients.
Acknowledgements
Funding support provided by St Luke’s Episcopal Hospital
and the Roderick D. MacDonald Research Fund.
Transparency Declaration
The authors declare that they have no conflict of interest.
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ª2011 The Authors
Clinical Microbiology and Infection ª2011 European Society of Clinical Microbiology and Infectious Diseases, CMI, 17, 868–872