Active Screening for C. auris Colonisation: A Preventive Step or an Excessive Measure? A Systematic Review

Patients' and surfaces' colonisation play a pivotal role in C. auris transmission. Understanding how, when, and where screening for colonisation should be done is important to control the spread.

This systematic review searched studies regarding C. auris patient colonisation, without previous outbreaks, until October 2024. Patient demographic and clinical data, sample type, collecting procedure, laboratory methods for strain identification, Clade determination, and susceptibility profile were collected.

Thirty-eight studies published between 2019 and 2023 across 18 countries were included using well-established inclusion criteria. Various body sites were screened mainly in patients admitted to intensive care units (ICUs). Patients had various comorbidities and were more commonly colonised during hospitalisation, compared to admission. Most of the isolates belonged to Clade I. Of 19 studies determining antifungal susceptibility, 15 reported resistance, mainly to azoles. Azole resistance was consistently associated with ERG11 substitutions (Y132F/K143R in Clade I, and V125A/F126L in Clade III).

Healthcare workers should be on high alert for older, long-term hospitalised, ICU patients with comorbidities and co-colonisation with other pathogens. Composite bilateral axilla-groin sampling should remain the standard minimum approach. Additional anatomical sites may be considered. Well-equipped laboratories are vital for precision identification and antifungal susceptibility testing.