Review: Candida auris Infections
24 Nov, 2024 | 19:50h | UTCIntroduction: Candida auris, first identified in Japan in 2009, has rapidly emerged as a global public health threat due to its multidrug resistance and propensity to cause difficult-to-control outbreaks in healthcare settings. This review by Lionakis and Chowdhary aims to provide clinicians with an in-depth understanding of the mycologic features, immune responses, epidemiology, risk factors, clinical manifestations, diagnosis, antifungal resistance, treatment, and prevention strategies associated with C. auris infections to inform effective patient care and containment measures.
Key Points:
- Mycologic Features: C. auris is a budding yeast that thrives in high-salt and high-temperature environments. It is divided into five clades (I–V) with distinct geographic distributions and varying virulence and resistance profiles.
- Immune Response: The interleukin-17 pathway is crucial in reducing skin colonization by C. auris, while phagocytes like monocytes, macrophages, and neutrophils are essential for clearing bloodstream and organ infections.
- Epidemiology: Reported in over 45 countries, C. auris is known for causing outbreaks in healthcare facilities due to its persistence on skin and surfaces and challenges in accurate identification. The CDC classifies it as an urgent threat, and the WHO places it in the “critical” group of human fungal pathogens.
- Risk Factors: Key risk factors include advanced age, indwelling medical devices, immunocompromised states, diabetes, recent surgery, use of broad-spectrum antibiotics or antifungals, prolonged hospitalization, and severe COVID-19.
- Clinical Manifestations: Primarily causing invasive infections like candidemia, C. auris is associated with high morbidity and mortality rates (30–60%). Up to 25% of critically ill colonized patients may develop invasive infections.
- Diagnosis: Accurate identification is challenging due to misidentification with other Candida species on conventional tests. Reliable methods include MALDI-TOF mass spectrometry, sequencing of rDNA regions, and molecular assays like PCR.
- Antifungal Resistance: C. auris exhibits clade-specific multidrug resistance, with most strains resistant to fluconazole and some resistant to echinocandins and amphotericin B. Resistance mechanisms involve mutations in the ERG11 and FKS1 genes.
- Treatment: Echinocandins are recommended as first-line treatment for invasive C. auris infections. Close monitoring is essential due to potential treatment failure and emergence of resistance. Amphotericin B formulations may be used in neonates or if echinocandin resistance is present.
- Prevention: Strict infection control measures are critical, including contact precautions, environmental cleaning with EPA-registered disinfectants effective against C. auris, surveillance screening, and cohorting of patients to prevent nosocomial transmission.
Conclusion: The rapid global spread of multidrug-resistant C. auris presents significant challenges for clinical management and infection control. Early and accurate diagnosis, appropriate antifungal therapy, and stringent prevention strategies are essential to improve patient outcomes and prevent further dissemination of this pathogen.