Residual elements of the bacteria Clostridium difficile survive on hospital bed linens even after being washed, according to a new study. Researchers said the findings provide hospitals another possible source for any outbreak after investigating more common causes for infection.
The study published Tuesday in the journal Infection Control & Hospital Epidemiology looked at inoculated swatches of cotton sheets with C. difficile that were then laundered with sterile uncontaminated pieces of fabric to measure the levels of contamination before and after washing.
One of the washing methods tested for the study followed the British National Health Service's policy procedures for decontaminating healthcare laundry. Researchers washed naturally contaminated bed linens in a commerical washer with industrial detergent at 167 degrees Fahrenheit for eight minutes. The study found the laundering process reduced C. difficile spore counts by only 40%, failing to meet microbiological standards for containing no disease-causing bacteria.
Dr. Gonzalo Bearman, chair of the Division of Infectious Diseases at Virginia Commonwealth University and a board member of the Board of the Society for Healthcare Epidemiology of America which publishes the journal that contained the recent study said the risk of infection from a bed linen that has been laundered by such methods was small. But he said the findings gave hospitals another possible explanation for the source of an outbreak once they've ruled out traditional causes.
"The focus first and foremost should be on hand hygiene and water, isolation of patients, a good and strong antibiotic stewardship program that limits antibiotic overuse, the daily disinfection of patient rooms—those are like the bedrock interventions," Bearman said. "If those things are being done with fidelity yet there are still ongoing elevated rates of C. difficile, you should definitely look at other possibilities such as a bio-burden."
Bearman also warned that hospitals using commercial washers to decontaminate sheets with C. difficile could be spreading the bacteria when washed sheets are then reused and mixed in with uncontaminated sheets.
C. difficile is a common infection acquired in healthcare settings, costing hospitals $4.8 billion a year in excess healthcare costs.
A 2015 study published in the New England Journal of Medicine estimated nearly 500,000 C. difficile infections occurred in the U.S. in 2011, resulting in 29,000 deaths. Approximately two-thirds of those infections were associated with an inpatient stay.
C. difficile bacteria are typically found in feces and can contaminate surfaces and items. Anyone who's taken antibiotics for a long period of time is particularly at risk of infection, a fact the Centers for Disease Control has cited to underscore its efforts to reduce unnecessary antibiotic use among providers. The agency estimated a 10% decrease in antibiotic use could reduce a hospital's rate of C. difficile infections by 34%.
Healthcare creates an estimated 5 billion pounds of laundry every year, according to the CDC. Agency guidelines in terms of environmental control involving the laundry process call for linens to be washed at a temperature of at least 160 degrees Fahrenheit for a minimum of 25 minutes and the use of chlorine bleach for an added measure of safety.
The SHEA study is not the first to raise the possibility of acquiring infections through bed linens.
A 2016 study published in the journal FEMS Microbiology Letters that investigated soiled linens washed in a facility in Seattle that processes linens for six local hospitals found that linens that tested positive for C. difficile had contaminated areas within the facility where they were stored.
Dr. Cindy Sears, president of the Infectious Disease Society of America, said the study's findings were not a cause for panic but rather a call for additional testing under more real-life circumstances to better understand the amount of potential risk.
Like Bearman, Sears said the study offered another avenue for study, but should not take away focus from the importance of antibiotic stewardship, which will ultimately have a much more substantial impact in driving down rates of C. difficile.
"It raises an interesting question," Sears said. "We know that a room that has had a prior patient can occasionally be a source for a subsequent patient, but that's not the bulk of the problem."
