Lab Update 34 – Candida auris Screening

September 2022
Ampath | ampath.co.za

Overview

Ampath now offers Candida auris colonisation screening using two modalities:

1. Culture-based screening
2. PCR-based screening

🧪 The choice of screening criteria should be determined by the hospital or infection prevention and control (IPC) team.

Who Should Be Screened for C. auris Colonisation?

Screening is recommended for individuals meeting one or more of the following criteria:

✅ Close healthcare contacts of a newly identified C. auris case

• Roommates or neighbouring patients in shared rooms or wards
• All patients in high-risk open units (e.g. ICU), especially with ongoing transmission

✅ Positive screen for carbapenemase-producing Enterobacterales (CPE)

• C. auris co-colonisation is frequently seen in these patients

✅ Recent hospital or long-term care facility admission

• Particularly if the facility is known to harbour C. auris

✅ Admission to high-risk units

• Such as ICU or oncology units
• Especially before invasive procedures or mechanical ventilation

Specimen Collection Guidelines

For all patients, the axilla and groin must be swabbed. This is the most consistently colonised site.

Specimens by Type:

🧫 Culture-based Screening

• Swab sites:
  • Left and right axilla
  • Left and right groin
• Urine: Preferred third specimen
  • If urine unavailable, submit swab from an alternate site

🧬 PCR-based Screening

• Swab sites:
  • Left and right axilla
  • Left and right groin
• Additional swab options (if urine not submitted):
  • Anterior nares
  • Wounds
  • External ear canal
  • Catheter exit sites
  • Rectum

Swabbing technique:

• Swab each site up and down at least five times to collect sufficient material.

Maximum of 3 specimens per patient:

1. Specimen 1 (swab): Bilateral axilla
2. Specimen 2 (swab): Bilateral groin
3. Specimen 3:
   • Culture-based: Urine (preferred)
   • PCR-based: Alternate site swab if urine unavailable

Test Comparison Summary

🧫 Culture-based C. auris Screening

• Specimen type:
  • Gel swabs (axilla + groin)
  • Urine
• Turnaround time: 48 hours
• Mnemonic: CAURSC

🧬 PCR-based C. auris Screening

• Specimen type:
  • Dry swabs (axilla + groin)
  • Alternate third site as needed
• Turnaround time: 24 hours
• Mnemonic: CAURISPCR

📌 For additional guidance or IPC support, please contact your local Ampath microbiologist or infection control representative.