Introduction
Candida auris is an emerging pathogen that causes nosocomial infections and is regarded as a major global health concern. With the exception of Antarctica, it has been isolated in 35 nations since its first discovery in 2009 as a unique species of Candida. High death rates are linked to invasive infections caused by C. auris. Due to its varying resistance patterns to several common antifungal medications used to treat other Candida infections, it is regarded as a multi-drug resistant species.
Fluconazole and other preventative antifungals have been overused in recent years, which is assumed to be the cause of the increased prevalence of non-albicans Candida species colonization and infection. The detection and management of this disease are challenging since laboratory yeast identification techniques frequently misidentify C. auris as other yeasts. Even in nosocomial settings where infection prevention and control protocols are in place, there is a risk of Candida auris spread.
It is a pathogen that is nationally notifiable in the US, which enables public health to monitor and contain its spread. Among the yeast species in the genus Candida is Candida auris. It got its name from the fact that it was initially removed from a patient’s external ear canal in a Japanese hospital. The yeast DNA analysis revealed a unique species that shared similar profiles with Candida pseudohaemulonii, C. duobushaemulonii, Candida ruelliae, and Candida haemulonii.
Transmission
It is easy for Candida auris to spread from person to person. Unlike most other species of Candida, C. auris is transmitted mostly through the host’s microflora rather than through contact with another individual. Like many other species of Candida, C. auris is not normally found within the human gastrointestinal tract and is not regarded as a resident commensal organism. C. auris likes to feed on skin, especially in the groin and axilla. After exposure, it may colonize hosts in a matter of days to weeks, and invasive infections may follow in a matter of days to months.
C. auris colonization can last for several months or even forever. Consequently, it is crucial to recognize asymptomatic colonized patients so that extra safety measures can be taken when they have surgery or indwelling device implantation. Additionally, these patients could transmit diseases to other patients and contaminate the environment.
When C. auris is shed from infected or colonized patients, it can spread through contact with contaminated surfaces and fomites. Research has revealed that C. auris can be discovered in patient rooms as well as public areas such as corridors, seats, beds, windowsills, counters, blood pressure cuffs, infusion pumps, and ventilators.
Shared, multipurpose medical devices like pulse oximeters and temperature probes could harbor C. auris. According to research conducted in laboratories, C. auris can last for seven days on both dry and wet surfaces.According to a different study, C. auris cells can be cultured for two weeks and remain alive for up to four weeks. Precautions against touch and isolation should stop C. auris from spreading nosocomially.
Physical Evaluation
A Candida auris infection presents clinically similarly to other species of the same genus. The nose, throat, sputum, lungs, pleural cavity, heart, blood, liver, abdominal cavity (peritoneal fluid), rectal or stool culture, urine, vagina, bone, axilla, groin, wounds/surgical tissue, pus, ear, and brain are just a few of the body sites from which C. auris has been isolated.
Colonization rather than true infection is most likely what isolates from non-sterile body locations including the genitourinary tract, skin and soft tissues, and lungs indicate. It is important to check for erythema, soreness, and purulent material on any indwelling devices, including urine catheters, ports, venous catheters, and prosthetic devices.
Bloodstream infections (fungemia), myocarditis, urinary tract infections, surgical wound infections, burn infections, skin abscesses (associated with catheter insertion), otitis, meningitis, and bone infections are among the clinical disorders that have been recorded.
It has been demonstrated that Candida auris grows well on the skin in contrast to other species, which are normally commensals of the gastrointestinal system and not usually linked to nosocomial transmission. A multilayer biofilm is formed by C. auris, which thrives in environments resembling perspiring axillary skin conditions.[46] individuals who have become colonized can spread the infection to other individuals. After exposure, colonization can happen anywhere from a few hours to many days, and invasive infections can show up days or even months later.
Management/Treatment
The amount of drug resistance and the potential for drug resistance to develop to the three main classes of antifungals is the most difficult part of managing invasive Candida auris infections, as was previously addressed. C. auris isolates were the subject of an Indian study that examined their susceptibility patterns. The results revealed that 90% of the isolates were resistant to azoles (fluconazole), 8% to polyene (amphotericin B), and 2% to echinocandins (anidulafungin and micafungin). According to the study, 13% of the isolates were multi-azole resistant and 25% of the isolates were multi-drug resistant. The minimum inhibitory concentration (MIC) for azoles, echinocandins, polyenes, and nucleoside analogs was abnormally high, according to the Centers for Disease Control and Prevention’s breakpoint study of isolates in the United States.
Research conducted in vitro indicates that the combined application of antifungals in a synergistic manner has yielded encouraging outcomes when treating multiresistant isolates with voriconazole and micafungin. This wasn’t shown, though, in other echinocandin and azole combinations.
Regarding treatment possibilities for C. auris infection, there is no hard evidence. Susceptibility testing is used as a guide when managing the majority of cases on an individual basis. Seeking advice from an expert in infectious diseases is strongly advised. When C. auris is isolated from non-invasive locations (such as the skin, urine, and respiratory tract), treatment should only begin in the event that a clinical illness is present. Patients who have been colonized with C. auris should not get treatment.
Differential Diagnosis, Prognosis and Complication
The differential diagnoses of Candida auris include invasive fungal infections caused by other species of Candida and comprise 95% of all invasive fungal infections such as Candida albicans, Candida glabrata, Candida tropicalis, Candida paratropicalis, and Pichia kudriavzevii. Other differentials are Aspergillosis, Bacterial sepsis, Cryptococcosis and Septic shock.
The phenotypic characterization, such as the appearance and color of C. auris colonies in culture, high tolerance to growth in high heat (up to 42C), and saline environments, helps distinguish it from other Candida species but should not be used as the sole method for identification. Phenotypic platforms typically mistake C. auris for C. haemulonii and different yeasts (C. famata, C. guilliermondii, C. lusitaniae, C. parapsilosis, C. sake, Saccharomyces cerevisiae, and Rhodotorula glutinis). Molecular identification methods are the standard-of-care testing for a definitive diagnosis of C. auris.
The mortality rate of invasive infections associated with C. auris is comparatively higher than that of other Candida species. The crude mortality rate associated with C. auris infections ranges from 30% to 72%. The variable mortality rate data may be due to several factors, including the extent of the infection, age, associated risk factors, and co-morbid conditions. Infections have been reported in preterm infants to the elderly. Pediatric populations showed a higher likelihood of survival. Early identification of Candida auris and prompt treatment with appropriate anti-fungal regimens are associated with higher survival.
The complications of invasive Candida auris infection vary depending on the extent of the infection, host co-morbidities, and resistance patterns. While the most common presentation of Candida auris infection occurs as bloodstream infection (fungemia), it may spread hematogenously to seed different organs and cause multi-organ dysfunction. Conversely, a localized infection may eventually become an overwhelming bloodstream infection and have further complications such as sepsis, multi-organ system failure involving the kidneys, heart, lungs, eyes, brain, liver, and spleen, and ultimately death.
Source
Sikora A, Hashmi MF, Zahra F. Candida auris. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563297/