cleaned instrument but had difficulty and then proceeded with a
scope that had been used on a prior patient, but had only been pre-
cleaned and not completely disinfected.
CDC investigators and the maker of the duodenoscopes linked to the
outbreak at UCLA determined staff members followed the manufactur-
ers' reprocessing directives to the letter. That biofilm wasn't able to be
removed from the scopes, even after they were cleaned properly, points
to a design that's challenging to clean. Specifically, it's difficult to com-
pletely remove bacteria from a duodenoscope's elevator mechanism dur-
ing manual cleaning, before proper high-level disinfection or sterilization
can take place.
Following the outbreaks, duodenoscope manufacturers have made
design changes to reduce risk of contamination in that problematic
