By Lynne M. Sehulster, PhD, M(ASCP), CMIP(AHE)
Editor’s note: This is the second of a series of articles about the role of healthcare laundry in infection prevention.
Maintaining both the quality and cleanliness of processed healthcare textiles (HCTs) prior to their use is a shared responsibility. It calls for a collaborative effort between laundry operators and the healthcare professionals in the recipient healthcare facilities. This maintenance phase is the last part of the overall laundry process of preparing reusable fabric items for use in the next clinical setting, and infection prevention is central to its success. Thus, it is useful to understand how efficiently contemporary laundry procedures reduce contamination; a perspective on the outbreaks that have been attributed to laundered HCTs; and an awareness of when and where, and how HCTs can become contaminated prior to use.
Microbial Inactivation/Removal Properties of the Laundry Phase
A review article published in 2015 summarized the published evidence supporting the notion that contemporary laundering procedures excel at both soil/organic matter removal and microbial contamination removal and inactivation.1 According to the Centers for Disease Control and Prevention (CDC) “hygienically clean laundry carries negligible risk to healthcare personnel and patients, provided that the clean textiles are not inadvertently contaminated before use.”2 The laundry process is primarily a soil removal process, but the combination of detergent use, agitation of the textiles during the wash, duration of the wash, use of laundry additives with antimicrobial properties, rinsing, and hot air drying together can achieve significant microbial reductions (i.e., > 8 log10).3 Antimicrobial chemicals for laundry use include but are not limited to quaternary ammonium compounds, chlorine compounds, hydrogen peroxide and other oxygenated formulations (some of which include peracetic acid), and ozone producing systems.1 Many of these chemicals are registered by the Environmental Protection Agency (EPA) as either laundry sanitizers or laundry disinfectants, and many are designed specifically for use with cooler wash water temperatures.4
Infectious Disease Epidemiology and Laundered HCTs
Laundered HCTs are hygienically clean but they are not sterile (the exception being surgical textiles which are sterilized prior to use), and they will accumulate microorganisms from patients, the environment, and anything that touches them while they are in use.5 Nevertheless, four decades of experience using laundered, reusable HCTs strongly supports the notion that current industrial laundry processes are effective in interrupting potential patient-to-patient transmission of infectious diseases.1 The significance of this assessment increases when one notes the annual volume of laundered HCTs produced for U.S. hospitals is estimated to be 4.34 billion pounds; this volume of clean HCTs increases potentially by several billion pounds when the clean HCT demands of non-hospital venues are taken into account.1, 6-7
Immunocompetent patients in general are not adversely affected from contact with hygienically clean, reusable HCTs despite anticipated accumulation of microbes from various sources (e.g., patient skin squames, microbial transfer from hands and other surfaces, microbes settling out from the air). A literature search, however, identified 13 outbreaks around the world attributed to laundered HCTs that were ultimately determined to be contaminated prior to use.1 Box 1 summarizes the main points describing these outbreaks; the earliest of these events was in the late 1970s and the latest outbreak occurred in Hong Kong in 2015.1, 8
Of these 13 outbreaks, seven occurred in the period 2004 – 2015 (53.8 percent). Five of these outbreaks were clusters of Bacillus cereus bloodstream infections (5/7, 71.4 percent) and two outbreaks involved invasive systemic infections due to fungi of the family Mucoraceae (2/7, 28.6 percent). The fact that more than half of the reported disease outbreaks attributed to laundered HCTs have occurred in the most recent 12 years in a more than 40-year period begs the question, what has changed in healthcare delivery in recent years? Four things come to mind: 1) significant advances in medical technology and treatment options are now available to treat diseases and conditions deemed incurable or untreatable only a decade or so ago; 2) the proportion of hospitalized patients with either severely compromised immune systems or medical conditions necessitating very lengthy hospital stays has steadily increased; 3) many of these severely immunocompromised patients require care in a protective environment; and 4) routine care for immunocompetent patients continues to move from acute-care hospitals to other healthcare venues (e.g., ambulatory care centers).2 In short, more hospitalized patients are at increased risk of acquiring a healthcare-associated opportunistic infection, including infections due to exposure to environmental pathogens.
The outbreak of infection due to Rhizopus delemar, an environmental fungus that was linked to contaminated HCTs in a New Orleans children’s hospital in 2009 provides insight into the epidemiology of this infection and the risk factors at work here.9 Five case-patients with different clinical conditions in three different critical care areas of the hospital were identified, each with an extended length of stay. All five patients died. An epidemiologic investigation to identify possible exposure risk factors found HCTs as the only item in common with the care for these patients. Applying the chain of infection to the analysis of the outbreak information provides some clarity. In its original presentation, the five links in the chain are: 1) presence of a pathogen; 2) an infectious dose of that pathogen; 3) a mode of transmission; 4) a susceptible host; and 5) a portal of entry.10
“Laundry A” provided laundered HCTs to all departments in this hospital, but only five patients were clinically susceptible to this opportunistic pathogen and became infected. All the other patients in the hospital during this period were presumably immunocompetent to prevent this pathogen from initiating infection. A medical chart review revealed that all five patients had significant clinical risk factors (i.e., immunocompromised, acidosis, hyperglycemic) for opportunistic Rhizopus infection.9, 11 All of the case patients developed cutaneous lesions on their skin at some location (e.g., face, neck, upper back, etc.), which suggests the mode of transmission was cutaneous via direct contact and the lesions became the portal of entry. In this outbreak, each of the case-patients had extensive exposure to laundered HCTs that were inadvertently contaminated with R. delemar.9 In the investigation of this outbreak, R. delemar was isolated from laundered HCTs, hospital areas where the HCTs were stored, and in clean HCTs and clean linen delivery carts at Laundry A.9 Sterilization of HCTs used by at-risk patients helped to stop this outbreak.
Inadvertent Environmental Contamination Compromises HCT Quality and Cleanliness
Referring back to Box 1, the majority of pathogens implicated in the outbreak investigations of infections associated with laundered HCTs are environmental microbes that are present in both indoor and outdoor environments. In each of the investigations efforts were made to identify the root cause leading to the inadvertent environmental contamination of the HCTs.
Three of these root causes are associated with laundry equipment maintenance and operation issues, which suggests that routine facility and equipment maintenance and process inspection should be priorities. Improper wash process parameter settings can affect all aspects of the wash cycle and reduce the overall level of microbial inactivation of the wash process. Three other root causes are related to improper HCT storage settings and control of dust from construction or other sources. It is well known that dust can serve as a carrier of organic matter contamination, bacteria, and fungal spores. Dust and lint control measures such as regular blow-downs and keeping a regular surface cleaning schedule are necessary to minimize the deposition of dust on clean HCTs as they move toward the packaging/bundling stage of the overall process. Once these packages/bundles are in either a holding stage or in storage, the storage units and/or carts should be designed to minimize any additional contact with dust. Strategies to help with dust control in the healthcare facility storage rooms include: 1) regular cleaning and disinfection of surfaces; 2) setting the area’s ventilation at positive pressure relative to adjourning spaces; 3) installing self-closing doors: and 4) storage rooms should not be near the loading dock. Additionally, HCT storage rooms should not be designed as pass-through areas, thereby keeping personnel traffic in the room to a minimum. Climate control in these rooms should be engineered to prevent departures from recommended settings for temperature and humidity.
In regard to inadvertent environmental contamination of laundered HCTs, one possible means of contamination control would be to apply an antimicrobial treatment to the HCTs. To date, however, we have not seen published reports describing the use of such treatments on a large scale. Furthermore, selection of the appropriate antimicrobial for this purpose requires some consideration re: how the chemical is applied, what are the target microbes (e.g., fungi, bacteria, viruses, etc.), and whether or not the chemical is safe for patients.1 The other method of contamination control involves steps that are taken to eliminate environments within the textiles themselves that can promote microbial growth on the fabrics. For example, fungi require three things to grow and proliferate: 1) a food source [e.g., cellulose]; 2) moisture; and 3) favorable environmental conditions [e.g., temperature and relative humidity].16 Some fabrics such as cotton contain large amounts of cellulose. Some degree of moisture can be present in laundry bundles if they are wrapped before the fabrics have fully dried out. And when these bundles are stored in settings with warm environments with fluctuations in temperature and humidity, fungi within these bundles can increase in numbers sufficient to pose a potential risk of infection to highly susceptible patients.
The importance of climate and dust control for laundry facilities and storage areas is undeniable. In the outbreak of Rhizopus spp. infections in a Hong Kong hospital in 2015, the investigators noted excessive levels of dust throughout Laundry A and a dew point of 84 degrees F in the facility, all suggesting poor environmental control. HCTs were warm and moist to the touch in the packing area. HCT storage areas in the hospital, laundered HCTs, and environmental surfaces in Laundry A tested positive for zygomycetes while surfaces and HCTs in a control laundry were negative.8
Effective control of inadvertent environmental contamination of HCTs requires commitment and diligence from all laundry operators and healthcare professionals who manage the production and use of hygienically clean HCTs. Staying on top of these responsibilities can be made easier through the use of checklists such as those provided by the Healthcare Laundry Accreditation Council (HLAC).17 Process control in the laundry facility, taking steps to ensure thoroughly dry HCTs, controlling ambient storage conditions, and dust prevention are significant responsibilities, but taking action on all of these will help laundry and healthcare professionals navigate safely through one of the most challenging intersections where healthcare laundry and infection prevention meet.
Lynne Sehulster, PhD, M(ASCP), CMIP(AHE), recently retired from CDC after 20 years of serving as the Division of Healthcare Quality Promotion’s subject matter expert on environmental infection control.
1. Sehulster LM. Healthcare laundry and textiles in the United States: review and commentary on contemporary infection prevention issues. Infect Control Hosp Epidemiol 2015; 36:1073-1088.
2. Centers for Disease Control and Prevention and the Healthcare Infection Control Practices Advisory Committee (HICPAC). Guidelines for environmental infection control in health-care facilities. Published 2003. Available at: https://www.cdc.gov/infectioncontrol/pdf/guidelines/environmental-guidelines.pdf Accessed 22 August 2017.
3. Fijan S, Koren S, Cencic A, Šostar Turk S. Antimicrobial disinfection effect of a laundering procedure for hospital textiles against various indicator bacteria and fungi using different substrates for simulating human excrements. Diag Microbiol Infect Dis 2007; 57: 251-257.
4. U.S. Environmental Protection Agency. Product performance test guidelines OCSPP 810.2400: Disinfectants and sanitizers for use on fabrics and textiles – efficacy data recommendations. Available at: https://www.epa.gov/test-guidelines-pesticides-and-toxic-substances/series-810-product-performance-test-guidelines Accessed 23 August 2017.
5. Dancer SJ, White L, Robertson C. Monitoring environmental cleanliness on two surgical wards. Int J Environ Health Res 2008; 18: 257-264.
6. Government Accounting Office. VA Health care: Laundry service, operations and costs. Available at: https://www.gpo.gov/fdsys/pkg/GAOREPORTS-HEHS-00-16/html/GAOREPORTS-HEHS-00-16.htm Accessed 22 August 2017.
7. American Hospital Association. Fast facts on US hospitals. Available at: http://www.aha.org/research/rc/stat-studies/fast-facts.shtml Accessed 25 August 2017.
8. Cheng VCC, Chen JHK, Wong SCY, et al. Hospital outbreak of pulmonary and cutaneous zygomycosis due to contaminated linen items from substandard laundry. Clin Infect Dis 2016; 62: 714-721.
9. Duffy J, Harris J, Gade L, et al. Mucormycosis outbreak associated with hospital linens. Ped Infect Dis J 2014; 33: 472-476.
10. Greene VW. Microbiological contamination control in hospitals. Hospitals JAHA 1969; 43: 788-88.
11. Spellberg B, Edwards J Jr, Ibrahim A. Novel perspectives on mucormycosis: Pathophysiology, presentation, and management. Clin Microbiol Revs 2005; 18: 556-589.
12. Facility Guidelines Institute. Guidelines for Design & Construction of Hospitals & Outpatient Facilities. 2014 Edition. Available at: https://www.fgiguidelines.org/guidelines/2014-hospital-outpatient/read-only-copy/ Accessed 24 August 2017.
13. ANSI/ASHRAE/ASHE Standard 170-2013. Ventilation of Health Care Facilities. Available as Appendix A in reference 12.
14. Healthcare Laundry Accreditation Council. Accreditation Standards for Processing Reusable Textiles for use in Healthcare Facilities, 2016. Available at: http://www.hlacnet.org/standards-documents Accessed 23 August 2017.
15. American National Standards Institute (ANSI) / Association for the Advancement of Medical Instrumentation (AAMI). ANSI/AAMI ST 65:2009 R 2013 Processing of Reusable Surgical Textiles for Use in Health Care Facilities. Arlington, VA; Association for the Advancement of Medical Instrumentation; 2009.
16. Szostak-Kotowa J. Biodeterioration of textiles. Int Biodeterioration Biodegradation 2004; 53: 165-170
17. Healthcare Laundry Accreditation Council. Checklist for 2016 Accreditation Standards. Available at: http://docs.wixstatic.com/ugd/076879_a2ad48dc9b1b4f88b826dafd5d4446e6.pdf