Candida Auris

Candida auris was initially isolated from the ear of a patient in Japan in 2009, which explains its name. About the same time, 3 other distinct clades of C. auris were identified in Africa, South America, and South Asia. Since then, it has been reported in more than 55 countries. In October 2022, the WHO categorized C. auris as 1 of the 4 most critical fungal pathogens, along with Cryptococcus neoformans, Aspergillus fumigatus, and Candida albicans

C. auris was first identified in the United States in 2013. The CDC first alerted clinicians and laboratories in the United States about C. auris, in June 2016.  C auris has gradually increased from 53 confirmed cases in 2016 to 330 in 2018, 476 in 2019, 756 in 2020, and 1,471 in 2021. C. auris has been identified in 27 states within the United States. 

C. auris has a strong propensity for colonization. The majority of colonized patients do not become ill with invasive C. auris infections.  Patients can remain colonized with C. auris months after being discharged from a health care facility and can be a source of nosocomial transmission if they are admitted to another facility. 

Approximately 5 to 10% of colonized patients eventually develop invasive infections. People with serious underlying medical conditions who have received multiple antibiotics, and who have had prolonged admissions to healthcare settings are at highest risk of developing invasive infections. C. auris is resistant to multiple anti-fungal agents and has a mortality rate as high as 60%. The majority of invasive cases involve bloodstream infections. Treatment failure of a Candida infection from any site should alert physicians to the possible presence of C. auris. 

C. auris has been identified from many body sites including bloodstream, urine, respiratory tract, biliary fluid, wounds, and external ear canal. Approximately half of clinical cases in the United States have involved the bloodstream and the remainder have been found in non-invasive body sites.

Traditional identification methods used by microbiology laboratories may misidentify C. auris as another Candida species or give no identification. The US Food and Drug Administration (FDA) has approved use of the Bruker Maldi Biotyper CA system (MALDI-TOF) to identify C. auris. 

Susceptibility testing and identification to species level is performed routinely on Candida species isolated from sterile body sites and upon request when isolated from other sites. Antifungal susceptibility testing by the CDC Antibiotic Resistance (AR) Lab Network found that 86% of isolates tested in 2020 were resistant to azoles and 26% were resistant to amphotericin B. Most concerningly, resistance to echinocandins, the first-line treatment for all invasive Candida infections, tripled in 2021 compared with 2020 (rising from 3 to 19 cases). A few isolates have been resistant to all 3 classes of antifungal drugs. 

C. auris can survive in warmer and saltier environments than other fungal pathogens. Screening high-risk patients by swabbing their armpits and groin, common sites of colonization, is one key to stopping its spread in health care facilities. There is no protocol for decolonizing patients, but regular bathing with chlorhexidine can reduce C. auris growth.

To reduce the risk of spreading C. auris, health care facilities might cohort colonized and infected patients, instruct health care personnel or other caregivers to wear gowns and gloves when providing care to them, clean their rooms with different products than usual, and encourage family members and others who come in contact with them to wash their hands often. 

Although health care workers can carry C. auris on their skin or gloves or other protective gear, they don’t appear to become colonized.

C. auris is a nationally notifiable condition and is reportable in many states. Laboratories that identify cases of C. auris should report cases immediately to the state or local health department and to CDC at This email address is being protected from spambots. You need JavaScript enabled to view it..

References

Rubin Rita, On the Rise, Candida auris Outwits Treatments and Travels Incognito in Health Care Settings. Published Online: December 28, 2022. doi:10.1001/jama.2022.17760

Centers for Disease Control, Candida auris, https://www.cdc.gov/fungal/candida-auris/candida-auris-qanda.html

Lyman M et al. Worsening spread of Candida auris in the United States, 2019 to 2021, Ann Intern Med, March 21, 2023; https://doi.org/10.7326/M22-3469