Microbial Contamination of Hospital Reusable Cleaning Towels and Laundering Practices

In a study published last year, researchers demonstrated that cloth towels used for cleaning hospital rooms contained high numbers of microbial contaminants and that hospitals are advised to determine whether the reuse of cloth towels increases the risk of pathogen transmission. 

Hospital cleaning practices are critical to the prevention of nosocomial infection transmission. To this end, cloth towels soaked in disinfectants are commonly used to clean and disinfect hospital surfaces. Cloth cleaning towels have been linked to an outbreak of Bacillus cereus and have been shown to reduce the effectiveness of commonly used quaternary ammonium disinfectants.

Sifuentes, et al. (2013) sought to determine the effects of laundry and cleaning practices commonly used in hospitals for washing, storage and disinfection of cloth cleaning towels on their microbial loads. Ten hospitals in Arizona, selected at random, participated in the study. Three clean cotton and microfiber towels were collected from each location, for a total of 30 towels. Each towel was placed into a sterile bag with 300 mL of buffered peptone water to ensure complete saturation of the towel. Each towel was manually kneaded until the liquid was completed absorbed, after which the peptone broth was extracted from the towel by wringing.  The extract was assayed using selected media for isolation for the various bacteria.

Buckets containing hospital-grade disinfectant were collected samples from the inside surface of a bucket used to soak the towels in disinfectant was collected at each hospital. Each disinfectant soaking bucket was swabbed just above the disinfectant liquid line. Samples from the towels and buckets were cultured for total bacteria (heterotrophic bacteria), coliform bacteria,  E coli, C difficile, MRSA, molds, and aerobic spore-forming bacteria.

The researchers found that of the total number of towels tested, 93 percent contained viable microorganisms even after laundering. The microbial load was higher on the clean towels than on the samples taken from the buckets containing disinfectant. Bacteria identified from the towels included Pseudomonas luteola, Pantoea spp, Klebsiella oxytoca, Klebsiella pneumoniae, Serratia plymuthica, Pasteurella pneumotropica, Aeromonas hydrophilica, and Micrococcus luteus. Molds identified from the towels included Aspergillus niger, Fusarium spp, and Cladosporium spp.

Statistical analyses indicated significant differences in total bacteria, mold, coliform bacteria, and aerobic spore-forming bacteria in the towels. Along with the overall differences, classification of the towels into four groups for analysis based on their fabric content revealed statistical differences between cotton and microfiber towels for all microbial contaminants. The microfiber towels harbored greater numbers of bacteria compared with the cotton towels.

A survey of cleaning practices was conducted at each hospital and included questions on  protocols used for cleaning rooms, towel use and laundry procedures. Specific questions related to the disinfectant(s) used, whether the towels were soaked in or sprayed with the disinfectant, exposure time, frequency of disinfectant changes, fabric content of the cleaning towels, towel washing and drying practices, and towel storage conditions.

The researchers found that 8 of the 10 hospitals reported using cotton towels, and the two others reported using microfiber towels. Two hospitals sent their linens to be laundered in a central facility, and the eight others laundered their towels in-house.  All but one of the hospitals reported a quaternary ammonium compound as their disinfectant of choice; the lone exception was a rehabilitation hospital that reported using bleach for terminal cleaning under all circumstances. All but one of the hospitals reported soaking their cleaning towels in a bucket with disinfectant.

Sifuentes, et al. (2013) concluded that hospital laundering practices appear insufficient to remove microbial contaminants and may even add contaminants to the towels.  It has also been previously reported that towels can interfere with the action of common hospital disinfectants. Either independently or in combination, these two factors may increase the risk for transmission of pathogens in hospitals. These observations indicate the need to critically reevaluate current hospital cleaning practices associated with reuse of cloth towels.

Reference: Sifuentes LY, Gerba CP, Weart I, Engelbrecht K, Koenig DW. Microbial contamination of hospital reusable cleaning towels. Am J Infect Control. 2013 Oct;41(10):912-5. doi: 10.1016/j.ajic.2013.01.015.