thermal , and chemical factors . Dilution and agitation in water remove substantial quantities of microorganisms . Detergents and surfactants function to suspend soils , reduce water surface tension , and also exhibit some microbiocidal properties .”
The role of healthcare textiles in the transmission of infection
Exactly where microbial contamination comes from has been the subject of some debate . As Sehulster ( 2015 ) acknowledges , “ Several research teams evaluating microbial ecology in healthcare settings have demonstrated that patients and their hospital beds are at the center as a source of room contamination , with pathogen levels dropping in concentration per area as the distance from the patient increases . This suggests that hospital bed textiles become contaminated primarily with the patient ’ s flora and to a lesser degree with those microorganisms already present in the healthcare environment , including pathogens that are particularly adept at long-term survival . However , the epidemiology of outbreaks associated with laundered , reusable HCTs strongly supports the notion that current industrial laundry processes are effective in interrupting patient-to-patient transmission .”
When looking at the question of outbreaks related to healthcare textiles , it is important to consider the volume of HCTs processed , to understand the overall relative risk . Sehuslter ( 2015 ) notes , “ A current estimate for the annual volume of U . S . hospital laundry is approximately 4.34 billion pounds as derived from Government Accounting Office and American Hospital Association data sources . However , when the laundry needs for nonhospital healthcare settings are included , a conservative estimate of the total volume of HCTs processed annually in the U . S . today for all healthcare venues would be several billion pounds higher .”
When examining outbreaks involving laundered HCTs , along with occupational exposures to pathogens on soiled HCTs , the occupational infection clusters involved exposure to infectious aerosols from mishandling of the textiles or failure to use personal protective equipment ( PPE ), Sehulster ( 2015 ) points out , the outbreaks of clinically symptomatic infection among patients are associated mostly with textiles contaminated with environmental pathogens after laundering or contaminated owing to a deficiency in the laundering process : “ At least 350 patients worldwide have been infected in 12 outbreaks over the past 43 years . Despite the presence of microorganisms on clothing and HCTs , there appears to be little to no evidence of patient-to-patient transmission of infection attributed to laundered textiles , even for Clostridium difficile infection . We have not found reports of C . difficile spore persistence on patient-care HCTs , nor have we found reports of patient-to-patient transmission of C . difficile infection associated with HCTs not mixed with cleaning cloths , etc ., during laundering .”
Sehulster ( 2015 ) continues , “ Of the 12 outbreaks , seven were due to contamination from Bacillus cereus occurring in the late spring or the summer months . Towels were noted as being contaminated with B . cereus in four of these seven events . Higher ambient temperatures ( which favor spore-forming microorganisms ), coupled with normally moisture-absorbent textiles , result in conditions that favor environmental pathogen proliferation . Root problems associated with the B . cereus outbreaks included dust contamination of the clean textiles , inappropriate wash / rinse water temperatures , and storage conditions that promoted microbial growth . Two of these root problems were also identified in a recent Rhizopus outbreak in Louisiana , where storage conditions may have encouraged fungal growth on the healthcare textiles . This outbreak was limited to a very small group of severely immunocompromised patients , even though contaminated healthcare textiles presumably were used elsewhere in the hospital . Of the 12 outbreaks , four reported problems with laundered textile storage in the hospital ; seven reported contaminated washing equipment , inappropriate wash cycle or water temperature settings , or recycled water issues ; and one attributed the outbreak to inadvertent contamination occurring during transit from the laundry to the hospital .”
The take-away message is that outbreaks involving environmental pathogens strongly suggest that transport and storage of cleaned healthcare textiles can present opportunities for post-laundering contamination of textiles . As Sehulster ( 2015 ) explains , “ Storage or holding areas for cleaned textiles should be designed and engineered to protect textiles from dust and soil . The importance of temperature , relative humidity , and moisture control in storage areas is central to preventing microbial proliferation in and on materials that have some organic components . Given that some HCTs may consist of fibers with high organic content ( cotton ) and some textiles absorb moisture by design ( towels ), textiles with high moisture content ( textiles packaged in plastic before they are completely dry ) might provide a favorable environment for microbial proliferation , especially if the ambient temperature in the textile package storage area is warm . Environmental pathogen contamination of healthcare textiles also draws attention to the necessity of proper water and equipment management in the laundry . Bacillus spores can be present in water , and water recycling can potentially build up the spore concentrations in the wash and rinse cycles . Additionally , laundry additives may lack sufficient sporicidal potency to inactive large numbers of these spores during laundering . Prompt removal of wet textiles from the machines and proper washer maintenance should help to minimize equipment contamination and biofilm development .”
Overall , Owen and Laird ( 2020 ) say there are limited studies in the published literature that investigate the transfer of microorganisms to or from textiles in simulated or real-life clinical settings . They note , “ There is currently insufficient evidence to conclude either way if the movement of textiles is a source of HAIs or not . Despite published studies providing a theoretical basis for healthcare linen as potential fomites , there is a lack of direct evidence linking textile contamination and the transmission of HAIs .”
These researchers do point to HAI outbreaks associated with the use of inappropriate laundering parameters , and note , “ The case studies reported in the published literature provide preliminary evidence of a link between HAIs and textiles ; their small sample size and retrospective nature makes it difficult to conclude a direct link between the contaminated linen and outbreaks . However , the outbreak case studies demonstrates that textiles are able to act as fomites and this evidence should not be ignored . Most of the outbreaks reported in the published literature were associated with opportunistic environmental bacteria rather than healthcare-associated pathogens , which does not provide evidence of patient-to-patient transfer of HAIs ( Sasahara et al ., 2011 ; Wright et al ., 2012 ; Hosein et al ., 2013 ; Duffy , et al ., 2014 ; Sehulster , 2015 ; Cheng , et al ., 2016 ; Teal , et al ., 2016 ), yet the transmission of environmental microorganisms is still of importance and should be controlled due to a proportion of