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By Gary Evans, Medical Writer
Multidrug-resistant Candida auris continues to threaten national emergence from endemic areas, finding safe harbor in step-down facilities and moving across the continuum to infect other patients.
These reservoir facilities include skilled nursing facilities for ventilated patients — so called “vSNFs” — and long-term acute care hospitals (LTACHs).
Hospitals are discharging high-acuity patients to these other facilities, which do not have a comparable level of infection prevention education and staffing, says Tom Chiller, MD, MPHTM, chief of the mycotic diseases branch at the Centers for Disease Control and Prevention. Intensifying the problem, the acuity of discharged hospital patients has been “ratcheted up” in recent years, he adds.
“It is really a dual-edged issue,” he says. “We have focused a lot of our infection control efforts in hospitals, as we should. But the step-down facilities, for lack of a better word, have been sort of forgotten about in the continuum.”
These reservoir sites are the latest problem in controlling a pathogen that presents many formidable challenges. For example, C. auris can evade lab detection without specialized equipment, as standard clinical testing may misidentify the pathogen with more benign Candida strains like C. haemulonii, the CDC reports.1
That contributes to ineffective antibiotic treatment, as C. auris can be highly resistant to first-line therapy with fluconazole and other antifungals. In addition, C. auris can become endemic in the environment, requiring strong sporicidal disinfectants to eradicate from surfaces. Throw in high mortality rates in frail patients and the ability to exploit weak spots along the healthcare continuum, and you have a storm that is near perfect.
“These vSNFs and LTACHs do not have the same staffing that a hospital has, and yet, these patients are still very sick. And — based on prevalence data in Chicago — they have a lot C. auris colonization,” Chiller says.
Indeed, a study2 presented recently in San Francisco at IDWeek 2018 revealed that Chicago healthcare facilities are struggling to contain C. auris, primarily because it has established reservoirs in step-down sites.
“C. auris has rapidly emerged in the Chicago area,” said Sarah Kemble, MD, medical director of the communicable diseases program at the Chicago Department of Public Health. “Repeat point prevalence surveys indicate transmission and amplification within vSNFs.”
That does not bode well for containment of C. auris, which is still primarily found in three states: Illinois, New York, and New Jersey. In similar findings, investigators in New York City recently reported the pathogen was moving across the continuum and posing challenges in a number of different settings.
“Epidemiologic links indicated a large, interconnected web of affected healthcare facilities throughout New York City,” they reported.3
“Of the 51 clinical case-patients, 23 (45%) died within 90 days, and isolates were resistant to fluconazole for 50 (98%),” they found. Overall, screening of 572 patients revealed that 61 were C. auris positive. In 12 of 20 facilities that were screened, at least one patient was positive for C. auris. Facilities with a positive culture included five vSNFs. In addition, 8% of all environmental samples taken in the facilities were positive for C. auris.
“Contamination of surfaces and objects in case-patients’ rooms and mobile equipment outside the rooms was common,” they found. “High-yield items included bedrails, IV poles, beds, privacy and window curtains, windows, and floors.”
In addition, patient colonization was found in sites with environmental contamination, suggesting a link to transmission. It is becoming increasingly clear that colonization can have consequences, Chiller says.
“We know based on this study in New York that at least 4% of colonized patients go on to develop invasive infections,” he says. “We know that colonization can be a risk for invasive disease, and that’s ultimately what we are trying to avoid. We also know that colonization is a risk for transferring C. auris to other patients. I think the environment is playing a major role in transmission.”
Various means of decolonization are under study, but there is no clear path forward, he adds.
“Chlorhexidine [bathing] is being embraced by some and not others. The jury is still out,” Chiller says. “Is it contact time? Is it using chlorhexidine more frequently? We don’t know. Maybe just bathing with soap and water more frequently could even be a decolonization method. We are actively searching other ways to think about this.”
The goal is reducing the pathogen bioburden enough to diminish transmission risk. If such bioburden is reduced, “we may be able to cut down a lot on transmission and really control these organisms, but this is a very large issue with very limited data,” he says.
C. auris was first detected in Japan in 2009. The first cases appeared in the United States in 2016. As of Oct. 31, 2019 — the most recent U.S. data available — there have been 457 confirmed cases of C. auris and 30 probable, the CDC reports.4 The vast majority are in the aforementioned three states, with a smattering of cases in nine other states. Overall, New York had 249 confirmed cases of C. auris and four probable; New Jersey had 96 and 22; and Illinois 91 and 4.
C. auris becomes a nationally reportable infection this year, a boost to surveillance that should be further aided by wider availability of rapid PCR testing for the bug. The decision by the Council of State and Territorial Epidemiologists to add C. auris to national reporting (see sidebar on the right) should bring its prevalence into better focus, but Chiller doubts it will result in a large spike in cases.
“People are looking pretty hard for cases, and I think if they had one they would report it to us because they want help containing it,” he says. “I think what this is going to do is set up a more sustainable way of tracking. It gives states an opportunity to tell their facilities that they need to report. It puts a system in place that is going to help us track the spread or our success in containing it over time.”
Another key development is increased use of PCR testing and analysis through the CDC Antibiotic Resistance Lab Network (ARLN), a nationwide group of labs that can rapidly identify pathogens and perform whole genome sequencing to shed light on transmission.
The wider use of rapid tests could allow active surveillance of incoming patients considered at risk. Standard culture testing for C. auris can take up to two weeks to yield results, meaning it will rarely inform patient isolation decisions. That is one reason the CDC has not emphasized active surveillance, but the agency does recommend isolating patients with known C. auris risk factors.
“Certainly, for known patients coming in, you do isolate,” he says. “With this PCR test, we may be able to screen much more rapidly and do a better job in determining if someone is positive — so you can put them in isolation or take them out.”
In addition to a heavy emphasis on hand hygiene and environmental cleaning, the CDC recommends5 that patients with confirmed or suspected C. auris infection should be cared for as follows in all settings:
Two Illinois patients were among the first U.S. cases of C. auris, and state health officials and clinicians strove to contain it. They thought they had done so after the first seven cases, but ongoing prevalence studies show otherwise, Kemble said.
Running through a timeline of the studies, she said in the Chicago area, facilities reported 24 clinical C. auris cases from May 2016 to January 2018. Ten involved bloodstream infection, the most severe manifestation of the pathogen. A surge began in 2018, as investigators continued prevalence studies in facilities that included seven vSNFs, five hospital ICUs, and three skilled nursing facilities. As of Sept. 17, 2018, Kemble and colleagues had performed some 50 additional prevalence studies, raising the total of C. auris to 76 clinical cases and 289 colonized cases.
“Thirteen colonized patients went on to develop clinical infections,” she said, a concerning finding since the proportion of colonized cases continues to grow.
In the first year of conducting surveys, only 2% of cases were colonized, but that number increased to 19% by September 2018 for all facilities. “Prevalence has only increased in vSNFs since January,” Kemble said. “On our most recent survey, colonization prevalence was at 71%. The majority of patients were found to be previously colonized with C. auris. Adding to the challenge in these facilities is a number of other MRDOs [multidrug-resistant organisms].”
In response, the Illinois state health department has sent out a series of alerts to raise awareness about C. auris, recommending contact precautions and emphasizing hand hygiene.
“Facilities must ensure interfacility communication regarding the status of any patient known to be infected or colonized with C. auris or other multidrug-resistant organisms at the time of transfer to another facility,” a health department alert states.6 “Communication should include any patient screened for a multidrug-resistant organism but for whom laboratory results are not available at the time of transfer.”
Citing risk factors and the presence of invasive devices, the health department reported that of “47 infected patients with available data, 83% had an IV device, 79% had wounds, 70% had a feeding tube, 66% had a urinary catheter, 62% had a tracheostomy, and 62% were mechanically ventilated.”
The alerts have been followed by direct calls to healthcare facilities that shared large numbers of patients with high C. auris prevalence, Kemble said.
The vSNFs in particular face challenges in implementing infection control measures due to understaffing and high staff turnover, she reiterated. Moreover, practices and regulations in long-term care facilities may run counter to traditional infection control approaches.
“One of the facilities was cited by a state regulatory agency for having too many patients on contact precautions because it wasn’t consistent with a ‘home-like’ environment,” Kemble said. “The patient dignity piece is a very strong theme in regulation, especially in Illinois. It often is at odds with what needs to happen with infection control.”
As in other investigations, environmental testing also is showing widespread contamination of the environment in some facilities, she said.
“Initially, with the first cases, we did not find C. auris except in a patient room that still had the patient in it,” Kemble said. “But subsequently, in screening environmental surfaces in vSNFs, we have found a lot of positives. Temperature probes as well as glucometers are items we are frequently finding positive — items that are shared up and down the hall.”
A recently published study in the United Kingdom reported a similar problem, with C. auris spreading to ICU patients via “reusable axillary temperature probes — indicating that this emerging pathogen can persist in the environment and be transmitted in healthcare settings.”7 In total, 70 patients were colonized or infected with C. auris, the authors reported.
Given the continuing spread of C. auris, Kemble and colleagues are teaching staff in the vSNFs and other nonhospital settings how to monitor hand hygiene compliance and use glow markers to show cleaning staff areas that remain contaminated.
“These kind of concepts were completely novel in many of these settings,” she said.
The findings were similar in New York, where investigators found infection control lapses in nonhospital settings, many of which had insufficient availability of alcohol-based hand sanitizers.
“A common problem with implementation of contact precautions was ineffective signage,” the investigators found. “One facility had no signs or other effective systems to identify persons around whom contact precautions should be taken.”
PPE problems included lack of knowledge about equipment needed, improper donning and doffing of gear, and insufficient stocks of appropriate supplies. Disinfection lapses included use of disinfectants without sporicidal label claims, inadequate disinfection of shared patient items, and lack of knowledge of necessary chemical contact times. The CDC is assisting infection control efforts, but the challenge ultimately falls to state and local health departments, Chiller says.
“These organisms are challenging to control. And certainly, if there are large reservoirs of these organisms existing in environments with suboptimal infection control and environmental disinfection, that is going to create an easy way for this to be transmitted and spread as patients go in and out of different facilities.”
And this raises the inevitable question: Can the CDC keep this bug at bay, contained in the endemic areas?
“I’m cautiously optimistic that we have been maintaining it at least in these three major areas for now,” Chiller says. “We have had one-off cases in other places when they have reacted very strongly. It did not appear to set up shop. But if it did so in LTACHs where we are not looking, we might not see it for a long period of time — until it bubbled over into acute care. That concerns me.”
Financial Disclosure: Peer Reviewer Patrick Joseph, MD, reports that he is a consultant for Genomic Health, Siemens, and CareDx. Senior Writer Gary Evans, Editor Jesse Saffron, Editor Jill Drachenberg, Nurse Planner Patti Grant, RN, BSN, MS, CIC, and Editorial Group Manager Terrey L. Hatcher report no consultant, stockholder, speaker’s bureau, research, or other financial relationships with companies having ties to this field of study.