Is screening for Candida auris recommended and what tests should be used?

Candida auris Screening Recommendations in Healthcare Settings

Screening for Candida auris is strongly recommended for high-risk patients, with axilla and groin composite swabs being the preferred sampling method using specialized culture media or PCR-based detection. 1, 2

Screening Indications

• Screening should be implemented for patients at high risk of C. auris colonization, including:

  • Patients previously hospitalized abroad within the past two months 3
  • Patients in critical care settings with prolonged ICU stays 4
  • Close contacts of known C. auris colonized or infected patients 1
  • Patients in healthcare facilities with known C. auris outbreaks 2

• The positivity rate for C. auris screening in high-risk patients is approximately 3-4%, justifying targeted surveillance 5

Preferred Screening Methods

• Composite swabs of the axilla and groin are the recommended sampling sites for C. auris screening 1

• Laboratory testing options include:

  • Specialized salt-containing media or chromogenic agars for culture-based detection 1
  • PCR-based molecular methods with high sensitivity and specificity 3

• Conventional identification systems often misidentify C. auris as other Candida species (C. famata, C. sake) or even as Rhodotorula or Saccharomyces, necessitating specialized testing 4

Screening Protocol Implementation

• For newly admitted high-risk patients:

  • Collect samples from axilla, groin, nares, throat, and rectum 3
  • Process using specialized culture media or PCR-based detection 3
  • Isolate patients until screening results are available 1

• For contact tracing:

  • Screen all close contacts of confirmed cases 1
  • Consider patients negative only after 3 consecutive negative screens taken at least 24 hours apart 1

Infection Control Considerations

• C. auris can persist in the healthcare environment and on patient skin for prolonged periods (up to a year or more) 6

• Patients who develop C. auris infections typically remain colonized even after treatment, requiring continued infection control measures 2

• Environmental cleaning requires sporicidal disinfectants (hydrogen peroxide, peracetic acid-based, or chlorine-based) as quaternary ammonium compounds have poor activity against Candida species 1

Common Pitfalls and Caveats

• Relying solely on standard identification methods may lead to misidentification of C. auris 4

• Standard culture techniques have limited sensitivity; specialized media and molecular methods improve detection 3

• Screening only a single anatomical site may miss colonization, as C. auris can colonize multiple body sites 3, 6

• Failure to implement proper infection control measures after identifying colonized patients can lead to outbreaks 2

• The current evidence base for C. auris screening is primarily from outbreak settings rather than prospective studies, suggesting that screening protocols should be informed by both available evidence and fungal microbiology principles 6