A retrospective Italian analysis on the characteristics of invasive fungal infections in the intensive care unit setting: CHARTER-IFI study

Background: Invasive fungal infections (IFI), prevalent in critically ill ICU patients, have gained attention due to post-COVID-19 epidemiological shifts. Notably, COVID-19-associated aspergillosis and candidiasis pose significant risks. WHO recognises key fungal pathogens, emphasising the need for enhanced research and interventions. Methods: The CHARTER-IFI study retrospectively examines 186,310 individuals admitted to ICUs in Italy from 01/01/2012-01/09/2023, utilising administrative databases covering around 10 million inhabitants. Adult patients were included having at least one ICU discharge diagnosis of IFI at their first IFI-related hospitalisation and having at least 12 months of available data prior to this hospitalisation. Results: A total of 746 IFI patients discharged from ICU (incidence of 4.0 per 1000 ICU-hospitalised patients), were included. Median age was 68 years, 63% were males, and the overall Charlson Comorbidity Index was 2.2. The top three diagnoses were candidiasis (N = 501, 2.7/1000 ICU-hospitalised patients), aspergillosis (N = 71, 0.4/1000), and pneumocystosis (N = 55, 0.3/1000). The evaluation of the comorbidity profile in IFI patients revealed the presence of hypertension (60.5%), use of systemic GC/antibacterials (45.3% during 12 months before and 18.6% during 3 months before hospital admission), cancer (23.1%), diabetes (24.3%) and cardiovascular diseases (23.9%). The mean (±SD) length of hospitalisation in ICU was 19.9 ± 24.1 days (median 11 days), and deaths occurred in 36.1% of IFI patients (within 30 days from discharge). Conclusions: This retrospective analysis among ICU-hospitalised patients described the burden of IFI in ICU, and its understanding could be crucial to strengthen surveillance, investments in research, and public health interventions as required by WHO.