Microbiological evaluation of the ability of the DEKO-190 Washer/Disinfector to remove Clostridium difficile spores from bedpan surfaces

Background: Clostridium difficile is a major nosocomial pathogen causing mild diarrhoea to life-threatening pseudomembranous colitis, and its spores frequently contaminate hospital environments and equipment. Washer/Disinfectors (WDs) are commonly used to clean and decontaminate soiled equipment in health care facilities. This study aimed to evaluate the effectiveness of the DEKO-190 WD in removing C. difficile spores from bedpans.

Methods: Plastic carriers were inoculated with suspensions of C. difficile spores in autoclaved (sterile) human faeces. The carriers were then taped to a sterile plastic bedpan which was subjected to short, long or intensive wash cycles in the WD using one of two test detergents: Formula A (generic) and Formula B (highly alkaline). Mean log₁₀ reductions in spores were calculated for each wash cycle.

Results: Mean log₁₀ reductions were 3.21(SEM ± 0.20) and 2.82 (±0.13) for Formula A and B, respectively, for the short cycle. The mean log₁₀ reductions using the long wash cycle were 3.65 (±0.44) using Formula A and 5.30 (±0.43) using Formula B, while log₁₀ reductions were 3.37 (±0.58) (Formula A) and 4.64 (±0.47) (Formula B) for the intensive cycle. Washing with the DEKO-190 significantly reduced spore concentrations on carrier surfaces on a bedpan. Spore counts were most effectively reduced when carriers were washed on a long or intensive wash cycle using an alkaline detergent.