Mucormycosis is an opportunistic fungal infection of the zygomycete family that primarily is a risk to immunocompromised patients (i.e., transplant recipients) or those with impaired skin integrity because of burns or other causes.
“Mucormycosis is characterized by tissue necrosis due to an invasion of blood vessels and subsequent thrombosis, which usually follows a rapid progression,” experts on the fungus emphasize.1 “The key to treatment is early and aggressive surgical debridement, along with high doses of intravenous antifungal therapy.”
Although fungal spores in the environment may be harmless to immune-competent patients, they can cause a 50% mortality rate in high-risk patients. Looking at the finer points does not necessarily reveal a granularity that would guide action. For example, it is not clear what level of fungi or other pathogens actually could cause an infection, which also depends to some degree on the immune competence and skin integrity of the patient population.
“[For] burn unit patients, bone marrow transplant patients … how many spores does it take to cause an infection?” said Janet Glowicz, PhD, RN, CIC, LTC-CIP, FAPIC, an infection preventionist (IP) in the Project Firstline initiative at the Centers for Disease Control and Prevention (CDC). “Again, we don’t know.”
Moreover, tracing a given infection to fungal contamination of laundry is an elusive challenge, but several studies have made the connection.2-4
“We know that as laundry comes out of the ‘tunnel washer’ — which is what many large laundry facilities use — they have removed the contamination that was on the soiled laundry, but keeping those linens clean is an underrecognized hazard,” Glowicz said.
However, visiting the hospital laundry facility, whether it is on or off site, is important, to meet the staff and review the process. An outbreak (to be described shortly) was traced to the laundering process.
“We see drug-resistant organisms, and we see other species of fungi, like Aspergillus, associated with textiles,” Glowicz said. “Mucormycosis specifically is a medical emergency. These are devastating infections. They have a very high mortality rate. They require frequent surgeries; aggressive, powerful antifungal medications; and they often affect immunosuppressed patients.”
The Centers for Medicare and Medicaid Services is not likely to survey a hospital laundry facility, but they will expect hospital leadership and infection control to ensure standards are being met and patients are safe.
“If there is a problem in a healthcare laundry, it is going to come to the infection prevention department and to the governing board of the facility,” Glowicz said.
Contamination After Dryer Cycle
Speaking at the same APIC presentation, Alexander Sundermann, DrPH, CIC, FAPIC, assistant professor of infectious disease at the University of Pittsburgh, described his experience as a beginning IP investigating an outbreak of likely healthcare-associated mucormycosis in four solid organ transplant patients.
The outbreak began with three infections in the same unit, so investigators hypothesized the cause was local and confined to a single room.
“I was a new IP in my first few months,” he said. “I was covering the cardiothoracic intensive care unit (CTICU) at our hospital. I vividly remember the day we got a call from our CTICU saying we’ve had a third case of an invasive mucormycosis patient within a transplant patient, and they were all in this one single room within our ICU.”
What followed was intensive investigation involving the local and state health departments as well as the CDC.
“We had these initial three patients that were in one single room,” Sundermann said. “All the facts pointed toward that room. We shut it down, our transplant program was shut down as well, and did some additional investigations.”
Then a fourth case appeared in a completely different building.
“We kind of threw our hypothesis out the window that it was this one room,” he said. “I started doing many environmental cultures, exploring the depths of our hospital, trying to pinpoint where these infections could be actually coming from. The only thing coming back positive was zygomycete — a type of a Mucor — was in our healthcare linens. We knew there was some evidence out there that linens could be a factor in this, and it was the only thing turning positive. So that’s where we turned our attention to.”
In a published account of the outbreak and remediation measures, Sundermann and colleagues began culturing various stages of transit for clean laundry coming from an off-site facility.5
“Surveillance cultures of freshly laundered healthcare linens (HCLs) and carts immediately upon delivery to the medical center and at the offsite [laundry] facility supplying the center demonstrated extensive contamination by Rhizopus, Lichtheimia, and other Mucorales,” they reported. “In contrast, Mucorales or other fungi were rarely recovered from cultures of hospital environments and supplies that were not associated with HCLs.”
With the contamination occurring beyond the hospital, a thorough investigation of the laundry facility was necessary.
“In order to pinpoint exactly where the contamination could be occurring from this facility, we decided to do a systematic culturing process, to see where the positivity rate [starts] increasing of these zygomycetes,” Sundermann told APIC attendees. “We cultured immediately after the wash/press, which was the earliest that we could actually culture them after getting cleaned; right after being dry from this large industrial dryer; then after being folded or handled from the machines; and then while being held in that area to be delivered to our hospital. We found a significant increase of contamination right after the dryer step.”
Breaking down the dryer process, they found that unfiltered air from the rooftop was being vented down to rapidly cool the dryers. “These dryers are so large and heat so quickly that they need to cool down rapidly in order for the folks working there to handle them,” he said. “That air has to come in extremely fast — it can’t be filtered or it might combust — brought down onto these clean sheets. We said, ‘Let’s go look at the roof.’”
There they discovered a thick layer of lint gathered near exhaust vents, which were close enough to allow the collected debris to be pulled down into the vents pulling air in to cool the dryers. The lint, which was being deposited directly on the linen as the dryers were cooled down, cultured positive for zygote fungi.
“We pinpointed air vents, storage of washed and folded HCLs in uncovered carts, and lint accumulation on the roof and within the plant as likely sources of contamination,” Sundermann and co-authors concluded. “Environmental remediation, quality assurance measures, and education directed toward these sources was associated with marked and sustained reductions in Mucorales-contaminated HCLs delivered to our center.”
Interventions included cleaning the roof and then subsequently recleaning it once per week.
“Since this remediation, we’ve had very good results of having clean linens without the presence of zygomycetes, because of this intervention,” he said. “We weren’t completely satisfied with this answer. We wanted to know what are other hospitals seeing out there.”
Knowing that mucormycosis outbreaks have been linked to contaminated laundry, Sundermann and colleagues conducted a follow-up investigation that performed similar stepwise fungal cultures on freshly laundered linens at 15 transplant and cancer hospitals that were nationally dispersed.
Visual inspections revealed that linens and laundry carts were unclean upon arrival at 33% (5/15) of hospitals. Moreover, 20% — three of the 15 hospitals — had evidence of hair, lint, insects, and other contaminants.
Freshly laundered HCLs were contaminated with Mucorales upon arrival at 47% — seven of 15 hospitals, they reported.6
“We were able to work with these facilities, give them our experience as well, and get some of their feedback,” he said. “Anecdotally, a lot of folks really improved their processes because of this data that we gathered. It was very revealing to see the true burden, [but] remediation is possible. There is a fix, but make sure that you work closely with your laundry facility.”
REFERENCES
- Hernández JL, Buckley CJ. Mucormycosis. StatPearls [Internet]. StatPearls Publishing. Updated June 12, 2023. https://www.ncbi.nlm.nih.gov/books/NBK544364/
- 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.
- Teal LJ, Schultz KM, Weber DJ, et al. Invasive cutaneous Rhizopus infections in an immunocompromised patient population associated with hospital laundry carts. Infect Control Hosp Epidemiol 2016;37:1251-1253.
- Duffy J, Harris J, Gade L, et al. Mucormycosis outbreak associated with hospital linens. Pediatr Infect Dis J 2014;33:472-476.
- Sundermann, AJ, Clancy CJ, Pasculle AW, et al. Remediation of Mucorales-contaminated healthcare linens at a laundry facility following an investigation of a case cluster of hospital-acquired Mucormycosis. Clin Infect Dis 2022;74:1401-1407.
- Sundermann AJ, Clancy CJ, Pasculle AW, et al. How clean is the linen at my hospital? The Mucorales on unclean linen discovery study of large United States transplant and cancer centers. Clin Infect Dis 2019;68:850-853.
Even pressed and folded, so-called “hygienically clean” hospital laundry can harbor fungal pathogens, sometimes in sufficient number to cause fatal mucormycosis infections in high-risk patients, outbreak investigators reported at the 2023 conference of the Association for Professionals in Infection Control and Epidemiology.
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