Case Report
Potential pandemic pathogens series: Candida auris, an imposter among us?


    Nederstigt1,2, L.G. Bakker3, D.J. van Westerloo1 and J. van Paassen1


    1Department of Intensive Care, Leiden University Medical Center, Leiden, the Netherlands

    2Department of Intensive Care, Tergooi Medical Center, Hilversum, the Netherlands

    3Department of Medical Microbiology, Tergooi Medical Center, Hilversum, the Netherlands


    Judith van Paassen,
    Case Report

    Potential pandemic pathogens series: Candida auris, an imposter among us?


    The last two years we have experienced the effects of the COVID-19 pandemic. Since pandemics have been a part of the history of humanity, we can be certain of new pandemics to appear, even more frequently than in the past, due to growth in the human population, increased travel, global warming and increasing spillover events due to decreased barriers between animals and humans. In this series, each edition we highlight a different potential pandemic pathogen and describe its characteristics, history and potential for global pandemics. This time we discuss Candida auris.

    Introduction of Candida auris

    Candida auris derives its name from the ear of a Japanese woman (Auris means ear in Latin), from where the yeast was first sampled, isolated and sequenced in 2009 [1]. After that, in 2011 in South Korea three patients had positive blood cultures with C. auris of two patients deceased despite treatment [2]. In the years to follow retrospective studies revealed that C. auris was already cultured in clinical samples since 1996 [3]. Furthermore it was discovered in other continents, its incidence was increasing, its resistance to antifungal medication was imminent and its pathogenicity in the seriously ill was a serious burden. Therefore C. auris is expected to become an increasing threat to our health care system. Do we have to be prepared?

    Clinical picture

    The clinical picture is not that different from other Candida species, although C. auris colonizes preferably the skin, which may be an explanation for the high capacity for person-to-person spread (BRON EIX). It has also been isolated from invasive locations including urine, bile, blood and the gut and is generally hospital acquired. It is considered as an opportunistic pathogen, and invasive infections are associated with health care exposures and underlying conditions [4], such as polytrauma, cardiovascular disease, sepsis, diabetes and cancer [5, 6] and several outbreaks were reported from ICU COVID-19 units [7]. Long-stay at a health care facility is probably one of the strongest predictors of C. auris colonization and infection [8, 9], especially for bloodstream infections [10].

    In particular, the use of medical devices is associated with colonization including tracheostomy, mechanical ventilation, percutaneous gastrostomy or jejunostomy tubes and indwelling urinary catheters. [5, 9]. Broad spectrum antimicrobial treatment (carbapenems) and antifungal treatment are other predisposing factors for colonization. [9].


    After its discovery, it soon became clear that C. auris was remarkable for its resistance to widely used antifungal regimens. Of C. auris isolates ninety percent is resistant to a least one antifungal medication and 30 percent to at least two [11] and it is shown that C. auris acquires further multidrug resistance rapidly in vitro [12]. In some areas the estimated resistance to fluconazole is over ninety percent and resistance to amphotericin B, voriconazol and caspofungin is generally over twelve percent [13, 14], although percentages and MICs (minimal inhibitory concentrations of antimicrobials) vary widely among different geographic regions [13, 15]. Contrary, the susceptibility for micafungin and anidulafungin,  is around 99 percent [13] and are recommended as initial therapy [16]. Pan resistant isolates are emerging, especially in areas where patients have been treated with antifungal drugs [9, 17, 18]. In case of reduced susceptibility to echinocandins, liposomal amphotericin B can be considered if tested susceptible. For treatment of pan-resistant C. auris infections several forms of combination therapies are proposed but efficacy is varying and clade- and isolate specific [19]. Treatment of colonization is not recommended and undesirable, since C. auris is difficult to irradicate and only adds to resistance [32]. Besides antifungal therapy, replacement of medical devices (if possible) is necessary because of biofilm formation, which is an important mechanism for longstanding colonization of catheters and devices in Candida species [20, 21]. C. auris biofilms, though in some clades less effective compared to C. albicans biofilms, have been shown to be more resistant to antifungals than their planktonic equivalents [22, 23] and one study showed significant biofilm formation in specific conditions mimicking the (axillary) skin [24].


    Globally, around 400 000 blood stream infections caused by Candida species occur annually with a mortality of 30-40 percent [25]. From the limited studies available we learn that mortality from C. auris bloodstream infection is 30-45 percent but highly variable [13, 14, 26]. Furthermore, C. auris infection is relatively frequent complicated by distant septic metastases (as spondylodiscitis and endocarditis) in twelve percent of the patients [27]. Because yeast infections occur most frequent in patients with compromised immune status, a long-standing serious illness, and serious pre- or coexistent extensive disease, it is difficult to distinguish whether mortality has a (partial) causal relationship to C. auris infections or  C. auris is being the marker for poor prognosis at baseline.

    Pandemic threat potential

    Epidemiology and spread

    As Candida auris is difficult to distinguish by macroscopic characteristics and traditional phenotypical methods

    Done from other Candida species and misidentification was common, several surveillance studies researched old samples of Candida infections throughout the past decades that were stored [3, 26, 28, 29]. Then, it became clear that C. auris was already amongst us since 1996 and incidence was rapidly increasing. From 2013 an increasing incidence of C. auris was reported worldwide, peaking in 2016 and decreasing thereafter [13] (Figure 1) with currently continuous outbreaks in the Americas [30, 31]  and Europe [32].

    Figure 1: Countries from which Candida auris cases have been reported (until August 2023)

    To date, five genetically diverse clades have been discovered [33]. Although, spread of C. auris mainly occurs in health care facilities [4], reservoirs are also found in natural environments and on apples (handled by human) [34, 35]. Three clades of C. auris emerged on three different continents including Asia, Africa and South America. Sequencing analysis suggests near-simultaneous emergence of C. auris rather than recent spread from a single source [26, 36].  Various hypotheses are described explaining this mechanism, including the increased thermal resistance of fungi following global warming as this reduces the difference between ambient temperatures in which fungi preferably grow and mammalian basal temperatures. This mechanism would make human an increasingly suitable host [37, 38]. As isolates in the Unites States and Europe include multiple clades of C. auris, it is thought that repatriation of colonized patients and healthy travelers are the most plausible explanation for the occurrence of C. auris in these parts of the world [26, 39].

    After discharge, clearance of C. auris is 62 percent in colonized patients, with clearance rates of 5.1 percent per 100 person-months [40] but the exact prevalence of C. auris in a healthy population is unknown. Epidemiological outpatient studies on Candida species in urinary tract infections and vaginal flora may be the best surrogates and generally find no C. auris among the isolates [41, 42] but, as C. auris has a history of misidentification in the past, these studies may be not representative.

    Getting close?

    After retyping stored Candida species, the first European case of C. auris occurred in 2007 in a patient that was repatriated from India to France [43]. Thereafter several large outbreaks have been reported in the United Kingdom (50 cases, during 2015–2017) [44, 45], Spain (203 cases, during 2017–2019) [46], Italy  (277 cases, from 2019) [32, 47] and Greece (74 cases, 2019-2021) [48]. As isolates of patients during a local outbreak generally form a single genetic cluster [44, 45], it is likely that the admission of one colonized patient can be the starting point of a significant outbreak.

    In 2018, in two different Dutch hospitals, two separate cases of C. auris were found. Both patients were of treated in a healthcare facility in India prior to admission [49]. No further cases have been described since then. However, quality assessment to evaluate the ability of Dutch clinical microbiological laboratories to identify C. auris from 2019 showed that only 74 percent of the laboratories were able to identify C. auris correctly in the past.  At present, widely used MALDI-TOF databases contain several C. auris spectra and it is likely that C. auris is correctly identified in the majority of the Dutch laboratories [50].

    Infection prevention

    To date, several strategies to contain C. auris transmission in health care facilities are proposed and have been more or less successful [7]. Based on these experiences, several guidelines and recommendations are developed with as agreement that early detection forms a corner-stone [6, 32]  including prehospital screening of patients transferred from other healthcare facilities. Patients who are colonized or infected with C. auris should be isolated during their entire hospital stay and direct contacts should be screened including patients that are already discharged [51].

    Detection of colonized patients is reliably done by rectal and skin swabs [52] and further surveillance is essential as C. auris specifically tends to colonize not only the human host but also its environment. Compared to other Candida species, C. auris shows higher resistance against various environmental stresses including long-term starvation and higher temperatures [53] and stays viable on plastic surfaces for weeks [54]. In several studies during a local outbreak C. auris was isolated from sphygmomanometer cuffs, patient tables, keyboards, temperature probes and infusion pumps, indicating that C. auris spreads and dwells on surfaces in patient rooms [27, 44] and despite strict measures, new cases continue to appear including medical staff [55]. Eradication from a health care facility usually takes a long standing joint effort including adherence to isolation and hygiene measures. C. auris is for example resistant to some common eradication methods such as ammonia and UV light, used in hospital cleaning [56, 57].


    Although not frequently reported in the Dutch health care facilities yet, C. auris is among the most threatening nosocomial infections to date. Colonization of the environment persists for weeks and once a health care facility is contaminated, it is very difficult to eradicate C. auris permanently. Furthermore, C. auris colonizes and infects our most vulnerable patients, is increasingly resistant to antifungal drugs, and is associated with a high mortality. Carefully mounted protocols including guidelines on infection prevention, detection, treatment and eradication are needed to prevent further spread and outbreaks. Increased awareness of this treat to our healthcare system is essential.


    All authors declare no conflict of interest. No funding or financial support was received.


    1. Satoh K, Makimura K, Hasumi Y, Nishiyama Y, Uchida K, Yamaguchi H. Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital. Microbiol Immunol. 2009;53(1):41-4.
    2. Lee WG, Shin JH, Uh Y, Kang MG, Kim SH, Park KH, et al. First three reported cases of nosocomial fungemia caused by Candida auris. J Clin Microbiol. 2011;49(9):3139-42.
    3. Kim MN, Shin JH, Sung H, Lee K, Kim EC, Ryoo N, et al. Candida haemulonii and closely related species at 5 university hospitals in Korea: identification, antifungal susceptibility, and clinical features. Clin Infect Dis. 2009;48(6):e57-61.
    4. Southwick K, Ostrowsky B, Greenko J, Adams E, Lutterloh E, Denis RJ, et al. A description of the first Candida auris-colonized individuals in New York State, 2016-2017. Am J Infect Control. 2022;50(3):358-60.
    5. Ruiz-Gaitán A, Martínez H, Moret AM, Calabuig E, Tasias M, Alastruey-Izquierdo A, et al. Detection and treatment of Candida auris in an outbreak situation: risk factors for developing colonization and candidemia by this new species in critically ill patients. Expert Rev Anti Infect Ther. 2019;17(4):295-305.
    6. Caceres DH, Forsberg K, Welsh RM, Sexton DJ, Lockhart SR, Jackson BR, et al. Candida auris: A Review of Recommendations for Detection and Control in Healthcare Settings. J Fungi (Basel). 2019;5(4).
    7. Prestel C, Anderson E, Forsberg K, Lyman M, de Perio MA, Kuhar D, et al. Candida auris Outbreak in a COVID-19 Specialty Care Unit – Florida, July-August 2020. MMWR Morb Mortal Wkly Rep. 2021;70(2):56-7.
    8. Cortegiani A, Misseri G, Fasciana T, Giammanco A, Giarratano A, Chowdhary A. Epidemiology, clinical characteristics, resistance, and treatment of infections by Candida auris. J Intensive Care. 2018;6:69.
    9. Rossow J, Ostrowsky B, Adams E, Greenko J, McDonald R, Vallabhaneni S, et al. Factors Associated With Candida auris Colonization and Transmission in Skilled Nursing Facilities With Ventilator Units, New York, 2016-2018. Clin Infect Dis. 2021;72(11):e753-e60.
    10. Caceres DH, Rivera SM, Armstrong PA, Escandon P, Chow NA, Ovalle MV, et al. Case-Case Comparison of Candida auris Versus Other Candida Species Bloodstream Infections: Results of an Outbreak Investigation in Colombia. Mycopathologia. 2020;185(5):917-23.
    11. Centers of Disease Control and Prevention, Factsheet on Candida Auris. 2021.
    12. Carolus H, Pierson S, Muñoz JF, Subotić A, Cruz RB, Cuomo CA, et al. Genome-Wide Analysis of Experimentally Evolved Candida auris Reveals Multiple Novel Mechanisms of Multidrug Resistance. mBio. 2021;12(2).
    13. Chen J, Tian S, Han X, Chu Y, Wang Q, Zhou B, et al. Is the superbug fungus really so scary? A systematic review and meta-analysis of global epidemiology and mortality of Candida auris. BMC Infect Dis. 2020;20(1):827.
    14. Osei Sekyere J. Candida auris: A systematic review and meta-analysis of current updates on an emerging multidrug-resistant pathogen. Microbiologyopen. 2019;8(8):e00901.
    15. Szekely A, Borman AM, Johnson EM. Candida auris Isolates of the Southern Asian and South African Lineages Exhibit Different Phenotypic and Antifungal Susceptibility Profiles In Vitro. J Clin Microbiol. 2019;57(5).
    16. Centers of Disease Control and Prevention, guideline on the treatment of Candida auris 2021 [Available from:
    17. Chowdhary A, Prakash A, Sharma C, Kordalewska M, Kumar A, Sarma S, et al. A multicentre study of antifungal susceptibility patterns among 350 Candida auris isolates (2009-17) in India: role of the ERG11 and FKS1 genes in azole and echinocandin resistance. J Antimicrob Chemother. 2018;73(4):891-9.
    18. Jacobs SE, Jacobs JL, Dennis EK, Taimur S, Rana M, Patel D, et al. Candida auris Pan-Drug-Resistant to Four Classes of Antifungal Agents. Antimicrob Agents Chemother. 2022;66(7):e0005322.
    19. O’Brien B, Chaturvedi S, Chaturvedi V. In Vitro Evaluation of Antifungal Drug Combinations against Multidrug-Resistant Candida auris Isolates from New York Outbreak. Antimicrob Agents Chemother. 2020;64(4).
    20. Kojic EM, Darouiche RO. Candida infections of medical devices. Clin Microbiol Rev. 2004;17(2):255-67.
    21. Shin JH, Kee SJ, Shin MG, Kim SH, Shin DH, Lee SK, et al. Biofilm production by isolates of Candida species recovered from nonneutropenic patients: comparison of bloodstream isolates with isolates from other sources. J Clin Microbiol. 2002;40(4):1244-8.
    22. Sherry L, Ramage G, Kean R, Borman A, Johnson EM, Richardson MD, et al. Biofilm-Forming Capability of Highly Virulent, Multidrug-Resistant Candida auris. Emerg Infect Dis. 2017;23(2):328-31.
    23. Larkin E, Hager C, Chandra J, Mukherjee PK, Retuerto M, Salem I, et al. The Emerging Pathogen Candida auris: Growth Phenotype, Virulence Factors, Activity of Antifungals, and Effect of SCY-078, a Novel Glucan Synthesis Inhibitor, on Growth Morphology and Biofilm Formation. Antimicrob Agents Chemother. 2017;61(5).
    24. Horton MV, Johnson CJ, Kernien JF, Patel TD, Lam BC, Cheong JZA, et al. Candida auris Forms High-Burden Biofilms in Skin Niche Conditions and on Porcine Skin. mSphere. 2020;5(1).
    25. Koehler P, Stecher M, Cornely OA, Koehler D, Vehreschild M, Bohlius J, et al. Morbidity and mortality of candidaemia in Europe: an epidemiologic meta-analysis. Clin Microbiol Infect. 2019;25(10):1200-12.
    26. Lockhart SR, Etienne KA, Vallabhaneni S, Farooqi J, Chowdhary A, Govender NP, et al. Simultaneous Emergence of Multidrug-Resistant Candida auris on 3 Continents Confirmed by Whole-Genome Sequencing and Epidemiological Analyses. Clin Infect Dis. 2017;64(2):134-40.
    27. Ruiz-Gaitán A, Moret AM, Tasias-Pitarch M, Aleixandre-López AI, Martínez-Morel H, Calabuig E, et al. An outbreak due to Candida auris with prolonged colonisation and candidaemia in a tertiary care European hospital. Mycoses. 2018;61(7):498-505.
    28. Oh BJ, Shin JH, Kim MN, Sung H, Lee K, Joo MY, et al. Biofilm formation and genotyping of Candida haemulonii, Candida pseudohaemulonii, and a proposed new species (Candida auris) isolates from Korea. Med Mycol. 2011;49(1):98-102.
    29. Lamoth F, Kontoyiannis DP. The Candida auris Alert: Facts and Perspectives. J Infect Dis. 2018;217(4):516-20.
    30. Villanueva-Lozano H, Treviño-Rangel RJ, González GM, Ramírez-Elizondo MT, Lara-Medrano R, Aleman-Bocanegra MC, et al. Outbreak of Candida auris infection in a COVID-19 hospital in Mexico. Clin Microbiol Infect. 2021;27(5):813-6.
    31. Desoubeaux G, Coste AT, Imbert C, Hennequin C. Overview about Candida auris: What’s up 12 years after its first description? J Mycol Med. 2022;32(2):101248.
    32. Candida auris outbreak in healthcare facilities in northern Italy, 2019-2021: European Centre for Disease prevention and Control; 2021 [Available from:
    33. Chybowska AD, Childers DS, Farrer RA. Nine Things Genomics Can Tell Us About Candida auris. Front Genet. 2020;11:351.
    34. Yadav A, Jain K, Wang Y, Pawar K, Kaur H, Sharma KK, et al. Candida auris on Apples: Diversity and Clinical Significance. mBio. 2022;13(2):e0051822.
    35. Arora P, Singh P, Wang Y, Yadav A, Pawar K, Singh A, et al. Environmental Isolation of Candida auris from the Coastal Wetlands of Andaman Islands, India. mBio. 2021;12(2).
    36. Casadevall A, Kontoyiannis DP, Robert V. Environmental Candida auris and the Global Warming Emergence Hypothesis. mBio. 2021;12(2).
    37. Garcia-Solache MA, Casadevall A. Global warming will bring new fungal diseases for mammals. mBio. 2010;1(1).
    38. Casadevall A, Kontoyiannis DP, Robert V. On the Emergence of Candida auris: Climate Change, Azoles, Swamps, and Birds. mBio. 2019;10(4).
    39. Chow NA, Gade L, Tsay SV, Forsberg K, Greenko JA, Southwick KL, et al. Multiple introductions and subsequent transmission of multidrug-resistant Candida auris in the USA: a molecular epidemiological survey. Lancet Infect Dis. 2018;18(12):1377-84.
    40. Bergeron G, Bloch D, Murray K, Kratz M, Parton H, Ackelsberg J, et al. Candida auris Colonization After Discharge to a Community Setting: New York City, 2017-2019. Open Forum Infect Dis. 2021;8(1):ofaa620.
    41. Achkar JM, Fries BC. Candida infections of the genitourinary tract. Clin Microbiol Rev. 2010;23(2):253-73.
    42. Paulitsch A, Weger W, Ginter-Hanselmayer G, Marth E, Buzina W. A 5-year (2000-2004) epidemiological survey of Candida and non-Candida yeast species causing vulvovaginal candidiasis in Graz, Austria. Mycoses. 2006;49(6):471-5.
    43. Desnos-Ollivier M, Fekkar A, Bretagne S. Earliest case of Candida auris infection imported in 2007 in Europe from India prior to the 2009 description in Japan. J Mycol Med. 2021;31(3):101139.
    44. Eyre DW, Sheppard AE, Madder H, Moir I, Moroney R, Quan TP, et al. A Candida auris Outbreak and Its Control in an Intensive Care Setting. N Engl J Med. 2018;379(14):1322-31.
    45. Schelenz S, Hagen F, Rhodes JL, Abdolrasouli A, Chowdhary A, Hall A, et al. First hospital outbreak of the globally emerging Candida auris in a European hospital. Antimicrob Resist Infect Control. 2016;5:35.
    46. García CS, Palop NT, Bayona JVM, García MM, Rodríguez DN, Álvarez MB, et al. Candida auris: report of an outbreak. Enferm Infecc Microbiol Clin (Engl Ed). 2020;38 Suppl 1:39-44.
    47. Di Pilato V, Codda G, Ball L, Giacobbe DR, Willison E, Mikulska M, et al. Molecular Epidemiological Investigation of a Nosocomial Cluster of C. auris: Evidence of Recent Emergence in Italy and Ease of Transmission during the COVID-19 Pandemic. J Fungi (Basel). 2021;7(2).
    48. Kohlenberg A, Struelens MJ, Monnet DL, Plachouras D. Candida auris: epidemiological situation, laboratory capacity and preparedness in European Union and European Economic Area countries, 2013 to 2017. Euro Surveill. 2018;23(13).
    49. Vogelzang EH, Weersink AJL, van Mansfeld R, Chow NA, Meis JF, van Dijk K. The First Two Cases of Candida auris in The Netherlands. J Fungi (Basel). 2019;5(4).
    50. Buil JB, van der Lee HAL, Curfs-Breuker I, Verweij PE, Meis JF. External Quality Assessment Evaluating the Ability of Dutch Clinical Microbiological Laboratories to Identify Candida auris. J Fungi (Basel). 2019;5(4).
    51. Kenters N, Kiernan M, Chowdhary A, Denning DW, Pemán J, Saris K, et al. Control of Candida auris in healthcare institutions: Outcome of an International Society for Antimicrobial Chemotherapy expert meeting. Int J Antimicrob Agents. 2019;54(4):400-6.
    52. Piatti G, Sartini M, Cusato C, Schito AM. Colonization by Candida auris in critically ill patients: role of cutaneous and rectal localization during an outbreak. J Hosp Infect. 2022;120:85-9.
    53. Chakrabarti A, Sood P. On the emergence, spread and resistance of Candida auris: host, pathogen and environmental tipping points. J Med Microbiol. 2021;70(3).
    54. Welsh RM, Bentz ML, Shams A, Houston H, Lyons A, Rose LJ, et al. Survival, Persistence, and Isolation of the Emerging Multidrug-Resistant Pathogenic Yeast Candida auris on a Plastic Health Care Surface. J Clin Microbiol. 2017;55(10):2996-3005.
    55. Al Maani A, Paul H, Al-Rashdi A, Wahaibi AA, Al-Jardani A, Al Abri AMA, et al. Ongoing Challenges with Healthcare-Associated Candida auris Outbreaks in Oman. J Fungi (Basel). 2019;5(4).
    56. Rutala WA, Kanamori H, Gergen MF, Sickbert-Bennett EE, Weber DJ. Susceptibility of Candida auris and Candida albicans to 21 germicides used in healthcare facilities. Infect Control Hosp Epidemiol. 2019;40(3):380-2.
    57. Cadnum JL, Shaikh AA, Piedrahita CT, Jencson AL, Larkin EL, Ghannoum MA, et al. Relative Resistance of the Emerging Fungal Pathogen Candida auris and Other Candida Species to Killing by Ultraviolet Light. Infect Control Hosp Epidemiol. 2018;39(1):94-6.