From ward to washer: The survival of Clostridium difficile spores on hospital bed sheets through a commercial UK NHS healthcare laundry process.

OBJECTIVE: To quantify the survival of Clostridium difficile spores on hospital bed sheets through the United Kingdom National Health System (UK NHS) healthcare laundry process (Health Technical Memorandum (HTM) 01-04) in vitro and on bed sheets from patients with C. difficile through the commercial laundry.

METHODS: Clostridium difficile spores were inoculated onto cotton sheets and laundered through a simulated washer extractor cycle using an industrial bleach detergent with sodium hypochlorite 15% and peracetic acid sour 14% (acetic acid and hydrogen peroxide; pH, 2-4). Spore survival on hospital sheets naturally contaminated with C. difficile was also assessed using a washer extractor plus drying and finishing cycles at a commercial laundry.PatientsNaturally contaminated C. difficile bed sheets were taken from beds of patients that had previously been diagnosed with C. difficile infection (CDI) and had received care on an isolated C. difficile ward.

RESULTS: The simulated washer extractor cycle, with an industrial detergent, demonstrated survival of 2 strains of C. difficile NCTC 11209 (0-4 colony-forming units [cfu] per 25 cm2) and ribotype 001/072 (0-9 cfu per 25 cm2). Before laundering, naturally contaminated bed sheets had an average spore load of 51 cfu per 25 cm2, and after washing, drying, and finishing, the spore load was 33 cfu per 25 cm2. Before and after washing, the C. difficile strain was identified as ribotype 001/072. Both the simulated and in-situ laundering processes failed the microbiological standards of no pathogenic bacteria remaining.

CONCLUSIONS: Clostridium difficile spores are able to survive laundering through a commercial washer extractor and may be contributing to sporadic outbreaks of CDI. Further research to establish exposure of laundry workers, patients, and the hospital environment to C. difficile spores from bed sheets is needed.