Breaking the Chain of Transmission to Prevent C Auris Infections in Health Care Settings

Candida auris, now reclassified Candidozyma auris, has emerged as a very concerning public health scourge. This rapidly spreading yeast poses a major challenge for infection control teams, and its frequent multidrug resistance calls for a systematic, strategic approach within health care facilities.

C auris infections can be severe, often leading to infections of the ears, wounds, and blood. Mortality rates can reach up to 60% of cases, especially with C auris bloodstream infections.¹

C auris is detected globally; the World Health Organization has listed it as a critical priority pathogen.² In addition, the US CDC declared C auris as an urgent microbial resistance threat due to the increasingly common strains that are resistant to all classes of antifungal therapies.^3,4

In health care facilities, C auris poses a particular challenge for infection control teams; once established, it is difficult to eradicate. The pathogen is impervious to standard disinfectants and can survive on surfaces for up to 3 months.⁵ There is also a growing concern about the increase in prevalence of this pathogen in health care facilities, potentially from asymptomatic colonized individuals. Estimates show 7045 clinical cases recorded in the US for nearly all of 2025, a 56% increase compared to the 4514 cases in 2023.^6,7

C auris requires an infection control response that accounts for the potential for rapid outbreaks, high antimicrobial resistance, and high in-hospital mortality. Infection control and clinical laboratory teams are pivotal in addressing C auris since the first step in any mitigation strategy is to identify patients who might be colonized or infected so staff members can rapidly manage patients and stop transmission through prompt isolation. This process calls for accurate and rapid pathogen detection to avert deadly outbreaks in health care facilities.

C auris: A Snapshot

C auris is now detected throughout the Americas, Africa, Asia, Europe, and the Middle East.⁸ The spread of this pathogen is alarming as cases continue to increase globally. In the past decade, approximately 30,000 to 40,000 documented global cases have been reported, and public health experts believe there is widespread underreporting.

While community spread is rising, this hardy pathogen remains frequently detected in health care facilities, posing a particular risk to patients under long-term care with devices such as ventilators or feeding tubes. Unfortunately, long-term care facilities are often reservoirs harboring C auris, facilitating continued transmission of this deadly pathogen.

Alarmingly, about a third of patients diagnosed with a C auris infection die within a month; mortality rates worsen when the infection enters the bloodstream.⁹ A CDC study found that cases of C auris in the bloodstream led to estimated mortality rates of nearly 50%.¹⁰ The same study showed that between 2017 and 2022, 20% of C auris cases reported in the US manifested as bloodstream infections.

Worryingly, the fungus has developed an effective arsenal of antimicrobial resistance mechanisms. Clinical data indicate that approximately 90% of C auris isolates are resistant to the widely used antifungal fluconazole.¹¹ While more susceptible to the broad-spectrum amphotericin B, 30% of isolates remain resistant. Currently, the echinocandin class of antifungal treatments remains most effective with less than 5% resistance, although that proportion is increasing.^4,11 In addition to worsening patient outcomes, this puts increasing pressure on clinical laboratory teams not only to detect the pathogen but also to generate resistance profiles for C auris isolates quickly enough to enable more effective treatment selection.

Techniques for Testing

To minimize the risk of C auris outbreaks in hospitals or health care facilities, it is essential to identify colonized patients so that proper isolation, protection, and disinfection procedures can be implemented. Universal screening of all admitted patients is neither institutionally cost-effective nor appropriate in most instances.

A targeted screening strategy for patients who may have been exposed to C auris and asymptomatically colonized is key. At-risk patients who should be tested include nursing home residents, long-term acute care patients, patients on respirators, individuals who have received antifungal therapy, and people from countries or regions with high rates of C auris.¹² In addition, high-risk patients include those who may have been exposed to C auris in a hospital or health care facility after sharing a room with an infected or colonized person, or those who received treatment from health care providers exposed to infected or colonized patients.

However, knowing whom to test is only half the story; knowing how to test is equally important. Rapid detection enables faster identification of patients colonized with C auris to trigger the necessary isolation protocols to prevent potential outbreaks in health care settings.

Culture-based testing has been the primary method for many clinical laboratories, but it fails to deliver results within a useful timeframe, taking 3 to 7 days to identify C auris using standard phenotypic and biochemical tests performed after culture. Culture alone is known to misidentify C auris as other pathogenic fungal organisms.¹³

Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry tests can identify C auris and, importantly, distinguish it from other Candida species by using an FDA-cleared reference library that includes C auris. While MALDI-TOF detection can be rapid, the procedure still requires an isolated colony from culture, which takes 2 to 3 days. This methodology has other major drawbacks: the high capital costs associated with mass spectrometry instruments, as well as the extensive operator training needed for the high-complexity nature of the test. As a result, MALDI-TOF testing is not a good fit for all laboratories.

Molecular tests such as PCR are more widely used across clinical laboratories as compared to MALDI-TOF given their capabilities to target pathogens with sample-to-answer automation, speed of results, and accuracy. In addition, many molecular tests are designated as moderate complexity, enabling wider use with less training than higher-complexity tests.

The FDA has authorized a PCR-based test for targeted detection of patients suspected of C auris colonization. Using composite swab samples from the bilateral axillae and groin collected from patients suspected of C auris colonization, the test delivers results within 2 hours.¹⁴ For diagnostic workups, the FDA has cleared molecular panel tests that include C. auris along with other targets frequently associated with active bloodstream infections.¹⁵ Other molecular tests also include genetic markers of drug resistance, offering health care teams useful guidance for therapy selection.¹⁶ Collectively, these powerful tools can support infection prevention and control strategies in health care settings.

Looking Ahead

Along with standard infection prevention and control measures such as isolation, disinfection, and personal protective equipment, rapid molecular testing can help reduce the risk of C auris outbreaks in health care settings. While antifungal treatment is not recommended for any individual colonized with C auris, targeted screening to identify asymptomatic patients remains key, as it allows teams to prevent transmission to other vulnerable patients. This can either be directly from colonized individuals or via environmental surfaces or medical devices that come into contact with them. Ultimately, rapid molecular testing is an essential tool for infection control teams seeking to gain the upper hand against C auris.

References

1. Kim HY, Nguyen TA, Kidd S, Chambers J, et al. Candida auris: a systematic review to inform the World Health Organization fungal priority pathogens list. Med Mycol. 2024;62(6):myae042. doi:10.1093/mmy/myae042
2. World Health Organization. WHO releases first-ever list of health-threatening fungi. Published October 25, 2022. Accessed April 7, 2026. https://www.who.int/news/item/25-10-2022-who-releases-first-ever-list-of-health-threatening-fungi
3. Houšť J, et al. Antifungal drugs. Metabolites. 2020;10:106. doi:10.3390/metabo10030106
4. Increasing threat of spread of antimicrobial-resistant fungus in healthcare facilities. CDC. Published March 20, 2023. Accessed April 7, 2026. https://www.cdc.gov/media/releases/2023/p0320-cauris.html.
5. Horton MV, Nett JE. Candida auris infection and biofilm formation: going beyond the surface. Curr Clin Microbiol Rep. 2020;7(3):51-56. doi:10.1007/s40588-020-00143-7
6. Twenter P. US records an increase in C auris clinical cases. Becker’s Clinical Leadership. Published December 31, 2025.
7. Candida auris, clinical: (week 1) weekly cases of notifiable diseases, United States, US Territories, and Non-US Residents week ending January 10, 2026. CDC Stacks. Published January 10, 2026.
8. Osei Sekyere J. Candida auris: a systematic review and meta-analysis of current updates on an emerging multidrug-resistant pathogen. MicrobiologyOpen. 2018;7(4):e00578. doi:10.1002/mbo3.578
9. Fact sheets. CDC. Published 2023. Accessed April 7, 2026. https://www.cdc.gov/fungal/candida-auris/fact-sheets/index.html.
10. Benedict K, Forsberg K, Gold J, et al. Candida auris-associated hospitalizations, United States, 2017-2022. Emerg Infect Dis. 2023;29(7):1485-1487. doi:10.3201/eid2907.230540
11. Pallotta F, Viale P, Barchiesi F. Candida auris: the new fungal threat. Infez Med. 2023;31(3):323-328. doi:10.53854/liim-3103-6
12. Screening recommendations for healthcare facilities. CDC. Revised December 15, 2025. Accessed April 3, 2026. https://www.cdc.gov/candida-auris/hcp/screening-hcp/index.html.
13. Identification of C auris. CDC. Revised February 26, 2026. Accessed April 3, 2026. https://www.cdc.gov/candida-auris/hcp/laboratories/identification-of-c-auris.html
14. Leonard J, Amamoto A, Bates M, Tran AT, Ghatbale P, Kline A, Pride DT. Evaluation of a novel PCR-based assay for the detection of Candida auris colonization. Microbiol Spectr. Published 2026. Accessed April 7, 2026. https://pubmed.ncbi.nlm.nih.gov/41511087/
15. Emery CL, Dhiman N, Chow S, et al. Performance of the LIAISON PLEX yeast blood culture assay for identifying 16 invasive fungal pathogens in blood cultures. J Clin Microbiol. 2025;63(7):e0036225. doi:10.1128/jcm.00362-25
16. Hsu C, Yassin M. Diagnostic approaches for Candida auris: a comprehensive review of screening, identification, and susceptibility testing. Microorganisms. Published June 24, 2025. https://www.mdpi.com/2076-2607/13/7/1461