Candida auris: The Major IPAC Concern
Candida auris is the yeast species representing the most critical Infection Prevention and Control concern due to antimicrobial resistance, classified by the CDC as an urgent public health threat with mortality rates up to 64%, multidrug resistance patterns, and unique ability to spread in healthcare environments. 1, 2, 3
Why C. auris is the Primary IPAC Threat
C. auris stands apart from other Candida species due to three defining characteristics:
- Multidrug resistance: Only 10.7% of C. auris isolates are susceptible to fluconazole, 90-98.2% remain susceptible to echinocandins, and approximately 43.1% are susceptible to amphotericin B 1, 4
- Healthcare transmission: Unlike most Candida species, C. auris colonizes patients indefinitely and persists in healthcare environments, enabling patient-to-patient spread 4, 5
- Pan-resistance emergence: Cases of resistance to all three antifungal classes have been documented, with a tripling of echinocandin-resistant isolates observed in recent years 2, 6
Epidemiologic Trends Supporting IPAC Priority
The global surveillance data demonstrates C. auris as an escalating threat:
- Rapid global spread: Since first identification in 2009, C. auris has been reported in over 20 countries across five continents 4, 5
- Outbreak potential: The largest U.S. outbreak occurred in New York with 801 patients identified by June 2019, demonstrating healthcare facility entrenchment 6
- Clade-specific resistance: Clades I and III show 94-96% fluconazole resistance, while Clade IV exhibits resistance to both azoles and echinocandins 7
Comparison to Other Candida Species
While other non-albicans species show concerning resistance patterns, none match C. auris's IPAC threat:
- C. glabrata: Shows increasing fluconazole resistance (10.6% in North America, 6.8% in Asia-Pacific) but lacks the transmission characteristics of C. auris 8
- C. krusei: Intrinsically resistant to fluconazole but remains relatively rare in hospital settings 2, 9
- C. albicans: Remains the most common species but maintains better antifungal susceptibility profiles 8, 2
Critical IPAC Implications
The unique combination of resistance and transmissibility requires aggressive infection control:
- Patient isolation: Strict isolation measures must be implemented for all C. auris cases 1
- Environmental persistence: Standard quaternary ammonium disinfectants are ineffective; sporicidal agents (hydrogen peroxide, peracetic acid, or chlorine-based) are required 1
- Screening protocols: High-risk patients and contacts require composite swabs of axilla and groin using specialized salt-containing or chromogenic media 1
- Clearance criteria: Three consecutive negative screens taken at least 24 hours apart are needed before discontinuing precautions 1
Diagnostic Challenges Complicating IPAC
Misidentification by conventional methods delays outbreak recognition:
- C. auris can be misidentified as other yeasts by commonly available identification methods, impeding early outbreak detection and control measure implementation 4, 5
- Specialized diagnostic capabilities and genomic studies are critical for proper identification and clade determination 7
Common Pitfalls
Avoid these critical errors in C. auris management:
- Never use fluconazole empirically when C. auris is suspected or confirmed, given only 10.7% susceptibility 1, 9
- Do not rely on standard disinfectants for environmental decontamination 1
- Never assume clearance without proper screening protocols as colonization can persist indefinitely 4
- Avoid delaying susceptibility testing on all clinical isolates, especially serial isolates from patients receiving echinocandins 6