Conventional laundering methods for hospital bedsheets left 60% of Clostridium difficile spores behind, increasing the risk of contaminating other bed linens and patients, new data show.

"The findings of this study may explain some sporadic outbreaks of C difficile infections in hospitals from unknown sources, however, further research is required in order to establish the true burden of hospital bedsheets in such outbreaks," senior author Katie Laird, PhD, head of the Infectious Disease Research Group, School of Pharmacy, De Montfort University, Leicester, United Kingdom, said in a news release.

Joanna Tarrant, PhD, from the Infectious Disease Research Group, School of Pharmacy, De Montfort University, and colleagues report their findings in an article published online October 16 in Infection Control and Hospital Epidemiology.

To test the effect of laundering on C difficile spores, the investigators used both naturally contaminated bedsheets from patients infected with C difficile and experimentally inoculated sheets. The sheets were washed according to the current UK National Health Service (NHS) laundry policy, as specified in Health Technical Memorandum (HTM) 01-04.

With the experimentally inoculated sheets, the authors initially tested the effects of washing without detergent (a control cycle), exposing the spores to the heat and agitation specified in the NHS protocol, and found that the sheets remained heavily contaminated.

After washing with detergent, the experimentally inoculated sheets still contained 0 to 9 colony-forming units (cfu) per 25 cm2 swatch. Moreover, previously sterile swatches washed in the load with the experimentally inoculated sheets held 0 to 14 cfu/25 cm2. Thus, the washing not only did not sterilize the original bedsheets but also spread the contamination to other items in the laundry load.

When the team repeated the analysis with naturally contaminated sheets laundered at a commercial laundry in accordance with the NHS protocol, the results were similar. Prior to washing, the sheets were contaminated with an average of 51 cfu/cm2. After laundering, the spore count was 33 cfu/cm2.

"The thermal disinfection conditions, described in HTM 01-04, were inadequate to fully decontaminate linen that had been naturally contaminated with C. difficile spores," the authors write.

The residual contamination could be contributing to sporadic outbreaks, the authors note, especially if facilities rent linens from companies that distribute bedding to multiple hospitals or healthcare facilities.

The study received no financial support. The authors have disclosed no relevant financial relationships.

Infect Control Hosp Epidemiol. Published online October 16, 2018. Abstract

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