Candida auris fungaemia outbreak in a tertiary care academic hospital and emergence of a pan-echinocandin resistant isolate, Greece, 2021 to 2023

Abstract

After the start of the COVID-19 pandemic, a rapid rise in reported numbers and wide geographic spread of Candida auris-related invasive infections has been observed globally. However, the contemporary epidemiology of C. auris fungaemias in Greece remains unknown. An outbreak of C. auris bloodstream infections has been ongoing for almost 3 years in a Greek tertiary care academic hospital, with 89 C. auris-driven episodes appearing in five waves every 6-7 months following peaks in colonisation rates by 3-4 months. All isolates clustered in clade I and were genetically related, 84% were fluconazole-resistant and all were non-resistant to amphotericin B and echinocandins, except one pan-echinocandin-resistant isolate (FKS1S639F mutant) recovered from a patient on empiric therapy with anidulafungin. Notably, C. auris was in 2023 the most prevalent (34%) cause of candidaemia in our hospital. The accelerated and long-term transmission dynamics of C. auris fungaemia underscore the need for rigorous infection control measures, while antifungal stewardship is warranted to contain the selection of echinocandin-resistant isolates.

Keywords: Candida auris; Greece; candidaemia; echinocandin-resistance; outbreak.

Figure 1

Epidemiological curve of Candida auris bloodstream infections during the COVID-19 transmission waves in different patient populations, Greece, 2021–2023 (n = 89)

Figure 2

Dendrogram of short tandem repeat genotypes and minimal spanning tree of representative Candida auris isolates from bloodstream infection and colonisation, Greece, 2021–2023 (n = 45) plus the first C. auris isolated in 2019 in Greece (ID 92)

Figure 3

Timeline of microbiological investigation and antifungal therapy of in vivo evolution to Candida auris echinocandin resistance in one patient, Greece, March 2022–June 2022