Current World Health Organization guidelines pertaining to the reprocessing of
surgical instruments in the face of potential iatrogenic transmission of
Creutzfeldt-Jakob disease (iCJD) are incompatible for the vast majority of devices. This has led to the advent of a range of new decontamination measures. Even without the implementation of these new procedures, the incidence of proven iCJD through surgery remains low. In this study, existing decontamination processes in sterile service departments have been evaluated using simulated washer-disinfector cycles on surgical grade
stainless steel wires inoculated with ME7
scrapie homogenate. The consequence of varying the soil drying times and choice of cycle pre-treatment on
prion removal were evaluated. Assessment of residual contamination at each cycle phase was carried out with the application of a sensitive fluorescent staining procedure to identify both total
protein and
prion-associated
amyloid. The study confirmed that immediate reprocessing following contamination was beneficial during the pre-treatment phase with either an enzymatic or pre-soak
wetting agent. Final total
protein levels at the end of the cycles, were not significantly different from those where the soil was allowed to dry. In addition, cycles involving a pre-treatment with either an enzymatic cleaner or pre-soak, whether the soil was allowed to dry or not, showed complete removal of detectable
prion amyloid. The results suggest that current decontamination procedures, combined with immediate processing of
surgical instruments, have the potential to be highly effective alone at reducing the risk of surgical transmission of CJD.