Candidozyma auris

Candidozyma auris (formerly Candida auris) is an emerging yeast pathogen that can cause severe, invasive and potentially life-threatening infections in humans. The organism was first isolated in Japan in 2009 from a swab of a patient’s external auditory canal. The species name auris (Latin for ‘ear’) has its origin in this. Since its discovery, the pathogen has spread rapidly across several continents and is now regarded as a significant nosocomial pathogen. In 2024, phylogenomic studies led to its reclassification from the genus Candida to the new genus Candidozyma [1, 2].

Candidozyma auris (C. auris) primarily affects people with underlying medical conditions or weakened immune systems, as well as those who have been in hospital for a long time or are using invasive medical devices, such as central venous catheters. Healthy people may carry the pathogen on their skin or mucous membranes without developing symptoms, yet still contribute to its transmission. Particularly problematic is the pathogen’s ability to develop resistance to several antifungal agents, making infections difficult to treat [3, 4].


Due to its significant impact on global public health, C. auris was included by the World Health Organisation (WHO) in the 2022 list of priority fungal pathogens, where it was classified as ‘critical’ (the highest priority level). The pathogen is therefore among the fungal pathogens that present the most urgent need in the areas of research, surveillance, prevention and the development of treatments [5].

Symptoms

Colonisation with Candidozyma auris is often asymptomatic. Colonised individuals may carry the yeast on their skin for long periods, particularly in areas such as the armpits, the groin or other moist parts of the body. Despite the absence of symptoms, these individuals can act as a reservoir for transmission within healthcare settings [4].

If an infection does occur, C. auris can cause a wide range of clinical presentations. The most severe form is invasive candidiasis, in which the pathogen enters the bloodstream and causes bloodstream infections (candidaemia). Affected individuals may develop fever, chills, hypotension and signs of sepsis, which persist despite antibacterial therapy. In addition, wound infections, urinary tract infections, ear infections, and infections of the central nervous system and other organs have been reported [4, 6].

The severity of the disease depends largely on the patient’s state of health. Those at particular risk include critically ill patients, patients in intensive care units, organ transplant recipients and immunocompromised individuals. Mortality from invasive C. auris infections is described as high, although many affected individuals also have severe comorbidities that contribute to an unfavourable clinical course [4, 7].

A particular challenge is the pathogen’s resistance to one or more commonly used antifungal agents, including fluconazole. Some strains exhibit multidrug resistance, which limits treatment options and further highlights the importance of infection prevention and early detection [5, 7, 8].

Routes of transmission

Unlike many other fungal pathogens, which predominantly originate from environmental sources, Candidozyma auris spreads efficiently within healthcare settings. Transmission occurs via both direct and indirect contact [6, 8].

Direct transmission can occur via the hands of healthcare staff following contact with colonised or infected individuals. Consequently, consistent adherence to hand hygiene is crucial to prevent further spread [7, 8].

Indirect transmission occurs via contaminated medical devices, hospital equipment, surfaces and objects in the immediate vicinity of patients. The pathogen is characterised by its ability to survive on inanimate surfaces for several days and, under certain conditions, even for up to three weeks. This long environmental persistence increases the risk of nosocomial outbreaks and necessitates rigorous cleaning and disinfection measures [9].

Healthcare facilities, particularly intensive care units, long-term care facilities and wards with particularly vulnerable patient groups, represent the main sites of transmission. Numerous outbreaks have been documented worldwide, which were frequently associated with persistent environmental contamination and delayed identification of colonised individuals [5, 8].

Distribution

Since its first description in 2009, Candidozyma auris has been detected on every inhabited continent and is now considered an emerging pathogen worldwide. Numerous countries have documented nosocomial outbreaks, which highlight the fungus’s potential for rapid international spread and establishment within healthcare systems [1, 5, 10].

The rise in reported case numbers in recent years is partly attributed to improved diagnostic methods and more intensive surveillance, but also reflects an actual epidemiological spread. International travel, patient transfers and the fungus’s long survival in healthcare settings have likely contributed to this trend [5, 8].

Cases have been documented in Europe, North America, Asia, Africa and South America, particularly among hospitalised patients requiring intensive care. National and international health authorities are monitoring developments very closely due to the potential for outbreaks and antifungal resistance [7, 10, 11].

Its classification by the WHO as a fungal pathogen of the highest priority underscores the global concern regarding its impact on healthcare systems [5, 7].

Measures to prevent infection

Prevention of the transmission of Candidozyma auris relies on a combination of surveillance, screening, isolation measures, hand hygiene, environmental hygiene and the appropriate use of disinfectants. Healthcare facilities should implement targeted screening strategies for at-risk patients and identify colonised or infected individuals at an early stage [8, 12].

Consistent hand hygiene is one of the most important preventive measures. Healthcare staff should carry out hand disinfection in accordance with current infection prevention guidelines before and after patient contact, as well as after contact with potentially contaminated surfaces or equipment [7, 8].

As the pathogen can survive on surfaces for prolonged periods, thorough cleaning and disinfection of patient areas and reusable medical devices are essential. Particular attention should be paid to frequently touched surfaces and equipment in the immediate patient environment [9, 12].

C. auris is very stable in the environment and can survive on surfaces for several days. In general, for inactivation of yeasts a yeasticidal disinfectant is recommended, which was tested e.g., according to EN13624 and EN16615 against Candida albicans. Due to the high environmental stability of C. auris, HARTMANN has tested the two surface disinfectants Mikrobac® forte and Dismozon® plus against C. auris. Both are effective against C. auris when applied in exposure times and concentrations as for the standard yeasticidal activity. In cases of C. auris, a yeasticidal disinfectant can therefore be used [13, 14].

Use surface disinfectants safely. Always read the label and product information before use.

Sources

1. Satoh K et al. (2009). Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital. Microbiol Immunol. 53(1):41–44.
2. Liu et al. (2024). Phylogenomic analysis of the Candida auris–Candida haemulonii clade and related taxa in the Metschnikowiaceae, and proposal of thirteen new genera, fifty-five new combinations and nine new species.
3. Wagener and Kurzai (2019). Candida auris: Profile of a new fungus. Dtsch Arztebl 2019; 116(29-30): [4]; DOI: 10.3238/PersInfek.2019.07.22.01
4. Smith et al. (2018). Candida auris: a review of the literature. Clin Microb Rev 31(1):e00029-17.
5. World Health Organisation (2022). WHO list of priority fungal pathogens to guide research, development and public health action.
6. Centres for Disease Control and Prevention (CDC) (2026). About C. auris.
7. European Centre for Disease Prevention and Control (ECDC) (2018). Candida auris in healthcare settings – Europe – first update.
8. Centres for Disease Control and Prevention (CDC) (2020). Candida auris: a drug-resistant pathogen that spreads in healthcare facilities.
9. Wißmann JE et al. (2021). Persistence of pathogens on inanimate surfaces: a narrative review. Microorganisms. 9:343.
10. European Centre for Disease Prevention and Control (ECDC) (2025). Survey on the epidemiological situation, laboratory capacity and preparedness for Candidozyma (Candida) auris, 2024.
11. Centres for Disease Control and Prevention (CDC). Candida auris – Infection Control Guidance.
12. National Reference Centre for Invasive Fungal Infections (2019). Factsheet: Candida auris.
13. Rutala WA et al. (2019). Susceptibility of Candida auris and Candida albicans to 21 germicides used in healthcare facilities.
14. Müller A et al. (2020). Investigation of the susceptibility of Candida auris and Candida albicans to chemical disinfectants using European Standards EN 13624 and EN 16615. J Hosp Infect. 105:648–656.