News & Articles

Biofilms - WFHSS Day 1

On the first day of the 2016 WFHSS congress in Brisbane, there were a number of papers presented that were of interest in the endoscopy reprocessing world.

Karen Vickery from Sydney drove home the challenges of biofilms. 

(If you would like some basic information on what biofilms are and how they behave, we would recommend going to The Center for Biofilm Engineering site at http://www.biofilm.montana.edu/biofilm-basics.html from which the following is copied):

In endoscopy, biofilms are a particular challenge since they form inside a scope channel, and are not fully removable by brushing etc, since they form and nestle in any small indentations in the channel wall. Staphylococcus attaches readily to human protein, and thereby compounds the risk.  Karen reported on a couple of studies, one that showed that 1.8% of operation-ready scopes had E coli elutable from their channels, and on destructive examination of these scopes 40% had colonies of E coli bacteria within their channels. In another study, she showed evidence that in an ICU that was about to be decommissioned there were biofilm colonies around the room in 41 of 44 samples taken from doors, curtains, blinds etc – and even after a year of storage in a dry sterile environment, these biofilms were still viable.  The EPS coating on a biofilm contains a lot of water that appears to be resistant to high levels of dehydration.  The overall message is that we cannot be complacent about disinfection and sterilisation processes at their being able to remove the viability of the bacteria encompassed within biofilms, and that biofilms are all around us.

Tillo Miorini from the Austrian Society of Sterile Supply reported on a study that indicated that manual pre-washing was in decline in some areas, that not all automated endoscope reprocessors (AER) in use are validated to ISO 15883-4, the standard for endoscope washer-disinfectors, and that not all the chemicals being used in some of the machines had been validated for use with that machine.  As a result, several critical incidents have been observed by accredited inspection bodies. (In the UK it has been observed that a number of auditing bodies are not completely up-to-date with published British, European, and International standards, and are in fact fequently missing non-compliant areas in UK SSDs.)

John van Bergen Henegouw from The Hague reminded the audience that all flexible endoscopes, according to European Regulations, should be reprocessed in an AER.  The AERs need to be validated to ISO 15883-4, but this international standard only validates the AER, and not the process.  He pointed out that there is currently no international process standard available. (In the UK, BES Decon has been proposing what we call the BESTest as a means to validate the whole process from entry into the AER to removal from the dryer/storage cabinet.)