CDC Discusses Candida auris With ICT: What Makes It So Dangerous?

The media has been inundated with inquiries about Candida auris (C auris), causing many to wonder about its potential risks and what infection preventionists and environmental hygienists should be aware of.

To address these concerns, Infection Control Today^® (ICT^®) spoke with Megan Lyman, MD, medical officer, Mycotic Diseases Branch, CDC, and Danielle A. Rankin, PhD, MPH, CIC, health scientist, Division of Healthcare Quality and Promotion, Prevention and Response Branch, Antimicrobial-Resistance Team, CDC. This interview was conducted in collaboration with our colleague Chris Spivey, editorial director for Pharmaceutical Technology, Pharmaceutical Technology Europe, and BioPharm International.

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ICT: Could you briefly explain what C auris is for our viewers who may or may not know this pathogen?

Megan Lyman, MD: C auris¹ is a type of yeast that is different from other species of Candida because it's often resistant to multiple antifungal medications. It can also cause serious infections, but it can also colonize or live on the skin without causing infections. And for that reason, it spreads easily in health care settings.

Megan Lyman, MD, medical officer, Mycotic Diseases Branch, CDC

(Photo courtesy of the CDC)

ICT: Initial press reports about the stubbornness of infection recall the alarms that were set off by Acinetobacter baumannii. While different pathogens exist, are they similar to C auris?

ML: C auris is very similar to some other resistant bacteria, like Acinetobacter baumannii, and similar to Acinetobacter, it can colonize the skin and shed from the skin into the environment where it can persist on surfaces for a very long time, even as long as a month. This is why both C auris and estimate a backdoor can lead to outbreaks and transmission in health care settings.¹

Chris Spivey: Is there a virulence factor you noticed or want to describe that we should watch out for?

ML: There are many questions about the variance of C auris and how it compares to other Candida species. There's some evidence, some animal studies that suggested it is not more virulent than other species of Candida that spreads more easily and can be more resistant, but not necessarily more virulent. But there's still a lot to learn. Some more recent publications have compared Candida bloodstream infections caused by C auris to those caused by other species to learn more about this.

Danielle A. Rankin, PhD, MPH, health scientist, Division of Healthcare Quality and Promotion, Prevention and Response Branch, Antimicrobial-Resistance Team, CDC.

(Photo courtesy of the CDC)

ICT: How would you compare C auris to Candida albicans? How would you compare those 2 pathogens?

ML: The difference is that C auris is much more resistant to antifungal medications,¹ and the fact that it can colonize or live on the skin and prefers it. C auris grows at higher temperatures and in saltier environments than some other species, which might allow it to survive on the skin more easily and in settings where patients may have fevers compared to other species.

ICT: How much have C auris cases increased recently?

ML: Clinical and screening cases have increased over the years since it was first identified and reported here in the United States.¹ Clinical cases are identified through clinical specimens collected during routine care to diagnose and treat infections; those have almost doubled in 2021. We continue to see them increase. Screening cases detected through colonization screening swabs more than tripled in 2021 and have continued to increase.²

ICT: Why has it become such a danger over the last few years when other pathogen transmissions have steadily decreased?

ML: There are likely multiple reasons. Some aspects of C auris make it challenging to control, so the fact that it sheds from the skin and contaminates environmental surfaces, as I mentioned, and it's also resistant to many routine health care disinfectants, particularly quaternary ammonium compounds. But there have also been deficiencies, early identification of cases, and infection control that likely led to transmission in areas with C auris for some time and spread into new areas.

But the timing of this recent increase in some findings from our [CDC’s] own public health investigations¹ suggests that C auris spread may have worsened because of the strain on health care and public health during the COVID-19 pandemic.¹ Things like staph [infections] and equipment shortages, increased patient burden and disease severity, and increased antimicrobial use changes in patient movement patterns, and poor implementation of non-COVID-19 [infection prevention and control] IPC measures. There was so much focus on improving infection control measures, specifically for COVID-19, that practices for resistant pathogens spread through contact may have been neglected a little bit during that time.

References:

1. Increasing threat of spread of antimicrobial-resistant fungus in healthcare facilities. CDC. March 20, 2023. Accessed May 2, 2023. https://www.cdc.gov/media/releases/2023/p0320-cauris.html
2. Popescu, Sv. Hot topics in IPC: Candida auris, Marburg virus, and pseudomonas from eye drops. Infection Control Today. Accessed May 2, 2023. https://www.infectioncontroltoday.com/view/hot-topics-ipc-candida-auris-marburg-virus-pseudomonas-from-eye-drops

This transcription has been edited for length and clarity.