As a child I’m sure we’ve all had nightmares about the
monster under our bed, or perhaps hiding in the closet. However, I don’t personally believe I ever
feared the beast lurking in the sink drain.
Unfortunately, this has become a very real concern or nightmare for
infection control professionals in healthcare facilities throughout North
America and likely around the globe. Multi-drug resistant strains of various
bacteria including Pseudomonas aeruginosa and Klebsiella oxytoca are taking up
residence in sink drains and wreaking havoc on the most immuno-compromised
patients. Just recently the infection control staff at Mount SinaiHospital (MSH) in Toronto published a study recounting their strategy
for addressing an outbreak that was traced back to the prevalence of K. oxytoca
in the drains of their ICU handwashing sinks.
This scenario echoes a similar situation encountered by staff at TorontoGeneral Hospital (TGH) years earlier.
In the case of TGH, the bacterial strain was different but the source
was the same – the sink drain in the ICU handwashing sinks. Some of you may be asking – as I did when I
first came across the TGH study – how in the world does bacteria dwelling in
the deep, dark recesses of a sink drain infect dozens of patients in an
ICU? The simple answer: splashing. Fact is, a dark and damp sink drain is the
ideal location for bacteria to populate and proliferate. When the tap is running, any splashing that
may occur when the water hits the drain could spread germs to both neighbouring
hand contact surfaces and directly to the hands of healthcare workers whom are
trying to comply with their hand hygiene needs.
So how can we solve this problem?
role. The first addresses the degree of
splashing and is more complicated as it typically involves the renovation or
replacement of the sinks in favour of those that are engineered to minimalize
splashing. The second intervention seeks
to address the contamination at the source, so as to prevent the potential for
transmission to other surfaces even if there is some splashing. This involves the thorough cleaning and
disinfection of the sink drain on a regular basis. Unfortunately, because the sink drain is not
only a perfect breeding ground for bacteria but also the ideal environment for
the establishment of biofilm this tends to be a more involved task than
everyday cleaning and disinfection. In
these situations particularly close attention needs to be paid to ensuring that
the disinfectant remains wet on the surface for the required contact time. This can prove difficult in a sink drain
where a liquid disinfectant solution typically has fleeting contact with the
contaminated surface as it races down the drain. Therefore, preference should be given to
rapid acting disinfectants and those that may be available in gelled formats
which ensure adhesion to the surface and subsequent contact time
compliance. An equally important
consideration is the type of disinfectant chosen for the application. Preference should be given to oxidizing
chemistries (e.g. hydrogen peroxide, chlorine based solutions) as they will
chemically work to lift and remove the biofilm from the surface. Other chemistries such as quaternary ammonium
compounds are generally ineffective at penetrating and removing the biofilm. In addition to selecting the appropriate
disinfectant, the utilization of a tool to effectively clean the drains should
also be strongly considered.
that your sink drains won’t be the cause of your next outbreak?
