Even during the COVID-19 pandemic, infection preventionists, nurses, environmental services personnel, and other health care workers cannot forget about C auris.
In 2009, the world was entrenched in another pandemic, albeit much smaller in scale than the current COVID-19 pandemic. It was novel swine-origin influenza A (H1N1) virus or “swine flu.” But this wasn’t the only pathogen to emerge that year. A new Candida species was isolated from a patient's ear in Japan–Candida auris (C auris). Auris means “ear” in Latin, hence its name. Growth of this pathogen over the past decade has been exponential, and during the pandemic, while we were singularly focused on SARS-CoV-2, C auris rates (Table 1) were accelerated, with several outbreaks reported. This article will address the key problems with this newcomer, and solutions will be provided.
The Yeast that Behaves Like Bacteria
C auris is a unique Candida species in that it behaves more like a bacteria than a yeast, and these traits include:
Problem #1: C auris is Difficult to Identify
Because C. auris is often misidentified as other Candida species, specialized laboratory technology is required to identify this pathogen correctly. Additionally, many clinical laboratories do not routinely identify yeasts at the species-level when isolated from a non-sterile body site.
Solution: It’s essential to know when to suspect and to seek out speciation for C auris. There are essentially four situations in which this should be done, and these are when:
1. Yeast is isolated from normally sterile body sites such as the bloodstream or cerebrospinal fluid. Speciation guides appropriate initial treatment, which can be administered based on the typical, species-specific susceptibility patterns.2
2. Candida is isolated from non-sterile body sites. In this scenario, consider species-level identification when:
3. A fungal isolate is identified that is known to represent potential misidentification of C auris, such as Candida haemulonii.2
4. You are seeing an increase in infections due to Candida species in a given care unit or there has been an increase of Candida isolated from urine specimens.2
This algorithm in Figure may help in determining when to speciate:2,4
If your facility lab does not have the technology to identify C auris, the Centers for Disease Control and Prevention (CDC) has a beneficial table, which summarizes misidentifications by the type of lab test used. The recommendation is that if any of these species are identified or if the species level cannot be determined, further characterization using appropriate testing methods should be sought through your local public health dept.2
Problem #2: C auris Persists in the Environment
Surface transmission is the primary route in which C auris is spread, and once it gets a foothold in a facility, it can be tough to eradicate. Colonized patients shed the pathogen into the environment, where this pathogen can survive on environmental surfaces for several weeks. Additionally, portable medical equipment has been implicated as a reservoir in several outbreaks.
For these reasons, a robust infection prevention and control plan, including cleaning and disinfection, is critically important. The CDC recommends using EPA-registered disinfectants that have kill claims for either C auris or Clostridioides difficile.2 Use of diluted bleach is another alternative.2 In fact, enhanced cleaning with bleach 3 times daily is how one facility stopped a C auris outbreak.5 It’s important to note that quaternary ammonium compounds (“quats”) are not as effective against this C auris.2 Disposable ready-to-use disinfecting wipes should be readily accessible for staff at point of use. And because 50% of surfaces are missed during manual cleaning, using adjunct disinfection technologies such as electrostatic disinfection systems can help ensure that nothing gets overlooked and no C auris is left behind.
Problem #3: C auris Spreads Rapidly in and Between Health Care Facilities
Outbreaks with C auris have proven challenging to control. This pathogen can spread in health care settings through contact with contaminated environmental surfaces, medical equipment, and fomites or from individual to individual, such as from unclean hands. Recent investigations have demonstrated that one-third to half of all patients on a given unit can become colonized with C auris within weeks of an index case entering the facility.6 Other studies have found that C auris may be found not only in patients’ rooms but also in hallways, on countertops, and medical equipment—particularly portable equipment. Shared multi-use patient care equipment such as temperature probes and pulse oximeters may act as reservoirs for this drug-resistant fungus.7 In addition to robust cleaning and disinfection, the CDC recommends contact isolation precautions in addition to standard precautions to contain C auris.2
With our attention on a single pathogen during the COVID-19 pandemic–SARS-CoV-2–a few emerging pathogens like C auris have been able to get a foothold in this country. C auris is a problematic pathogen that has proven to be challenging and difficult to contain. The evidence-based recommendations provided in this article should be considered if you are faced with C auris.
Footnote: This article was originally published as a blog in December of 2021 at www.CloroxPro.com.