A study I recently came across by Halten et al of the
University of Houston investigated the potential of writing pens as a source of
transmission, which could be significant for hospital infection control
practices when you consider the ubiquity of the instruments in healthcare
facilities. As this is tradeshow season
where sharing of pens is a virtual second by second occurrence, I was curious
to find out just how contaminated pens could get.
For the study, the clinical investigators responsible for
enrolling patients into a study investigating antibiotic associated diarrhea
were given a new writing pen each day.
They were then randomly assigned each day to clean the pen between
patient visits while the non-intervention group did not clean the pens. After
using the pen for the entire day to enroll patients, the investigators put the
pen in a sterile labeled bag. The pens
were then immediately transported to the laboratory. Four unused writing pens
were used as controls to assure that pens were not previously contaminated with
microorganisms.
Unfortunately the sample size in the study was quite
small, just 23 pens (10 in the intervention group, and 13 in the
non-intervention group), in addition to the four control pens. For each group,
between 2 and 11 patients touched each pen, along with the assigned
investigator. In the non-intervention
group 12 of 13 pens showed bacterial growth compared with 4 of 10 pens in the
intervention group. No growth was observed on control pens.
No Gram-negative bacilli, such as Pseudomonas spp.or E.
coli, were identified in either group, which tells me that the investigators
were being fastidious hand washers at least for the duration of the test. There was however a significant difference in
the Gram-positive cocci, presumptively identified as Staphylococcus spp. and
Enterococcus spp. in the intervention compared with the non-intervention group.
The study showed that cleaning/sanitizing the pens can
significantly reduce the level of potential pathogenic bacteria. This is an important finding indicating that
the risk of transmission of healthcare-associated pathogens can be decreased
with the use of a sanitizing agent for wiping fomites such as writing pens
between patients. 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.
Seeing as I head to the CHICA-Canada conference this
Sunday, I think perhaps I'll pack extra pens and be sure NOT to share
mine. I have a nasty habit of putting my
pen in my mouth and I can't trust that everyone will be as fastidious in their
hand washing as the clinical investigators in this study....
Hasta la vista!
Lee
aka “The Germinator”
