To get us in the mood for Dr Nneoma Okeke’s Journal Club tomorrow (register here!), I’ve been reading the paper that will be covered. Over the past two decades, a huge population-based study in Queensland, Australia sheds light on the evolving landscape of Candida and Candida-like species bloodstream infections. This analysis, including 2,586 episodes across 2,420 patients, reveals critical trends in species prevalence, resistance patterns, gender differences, and clinical outcomes that have significant implications for healthcare practices.

The genomic epidemiology of Candida and Candida-like species is frankly beyond me. It’s a complicated space and really the domain of a specialist fungal taxonomist! But, as we can tell from the recent reclassification of Candida auris to Candidozyma auris, the taxonomical sands shift frequently.

One of the most striking findings of this study was the shift in species distribution. While Candida albicans remained the most common pathogen, its prevalence declined over time. In contrast, Nakaseomyces glabratus (formerly Candida glabrata – yet more fungal reclassifcation!) and Candida dubliniensis showed notable increases. The rise of these species, particularly those with higher resistance profiles, underscores the need for careful surveillance and responsive approaches to treatment.

Overall, resistance to fluconazole and echinocandins remained low, with fluconazole resistance decreasing from 4.5% to 2.2% over the study period. However, recurrent BSI episodes exhibited higher resistance rates, especially to echinocandins, which rose to 2.0%. This trend has been noted with bacterial BSIs too, where recurrent infections are more likely to be resistant to antibacterials.

Females were more likely to experience fluconazole-resistant infections and had higher recurrence rates within one year. Perhaps underling this, females were more likely to have polymicrobial infection and a urinary or pelvic source of infection. These findings have implications for antifungal stewardship in both community and hospital settings.

Mortality rates remained relatively stable over the 20-year period, with a 30-day all-cause mortality of 21%. Candida tropicalis was associated with increased mortality, whereas those with C. parapsilosis complex were linked to better survival outcomes. Does this mean that 21% of patients with Candida BSI will die from their infection? Not at all – this is all-cause mortality, and pretty much all of the patients with these invasive fungal infections have serious underlying disease. Indeed, factors such as older age, ICU admission, and higher Charlson Comorbidity Index scores were independently associated with higher mortality, meaning that it’s quite difficult to interpret the mortality-related outcomes from this study.

Around 3% of cases reoccurred within one year. Recurrence was significantly associated with infections caused by uncommon Candida species and those with an endovascular source. Perhaps this gives us some pointers as to how to prevent these recurrent infections.

In conclusion, this comprehensive study provides helpful insights into the epidemiology of Candida BSI, highlighting changes in species prevalence, resistance patterns, and gender-related differences. The emergence of C. auris in other parts of the world suggests that the low rates of antifungal resistance are under threat.

Hope you can join us for the Journal Club tomorrow (register here!).