What is the burden of aspergillosis and other opportunistic fungal infections in patients with severe influenza and COVID-19 in the ICU?

ABSTRACT

BackgroundCo-infection with Aspergillus previously described to cause significant morbidity and mortality in those with severe Influenza, has more recently been described in COVID-19. ‘Influenza-Associated Pulmonary Aspergillosis’ (IAPA) and ‘COVID-Associated Pulmonary Aspergillosis’ (CAPA) have been reported in up to 23% and 35% of severe disease, respectively. Establishing evidence of invasive Aspergillosis (IA) in these patients is challenging, requiring specific clinical, radiological and microbiological criteria. The burden of IAPA and CAPA in the ICU in our region is unknown.AimsTo identify the incidence of invasive Aspergillosis (IA) and other opportunistic fungal infection in those with severe Influenza and COVID-19 in a district general hospital, Fife, Scotland.MethodsRetrospective cohort review of ICU admissions with severe Influenza or COVID-19 from May 2017 - February 2021. IA was diagnosed using international definitions according to EORTC/MSG, AspICU and modified AspICU criteria.Results89 patients were identified with Influenza (27;median age 53.3 yrs, male 56%) and COVID-19 (62;median age 59.1 yrs, male 61%). No case satisfied criteria for definite IA, however, the majority of patients did not undergo all relevant tests;CT imaging features in 26/89 (29.2%), and fungal biomarkers in 3/89 (3.4%). Two patients demonstrated Aspergillus culture from respiratory samples but did not meet other criteria. Fungal infections were identified in 39/89 (44%), the majority Candida (37), mostly from ET secretions (54%). Candida was significantly higher in COVID-19 than in Influenza, including 2 patients with Candidaemia. Positive fungal culture was associated with increased length of stay (43d vs 20d), ICU bed days (26d vs 19d), but not mortality (33.3% vs 30.0%). Few patients (7.9%) received antifungal treatment, with possible explanations including unclear diagnosis, high costs, uncertain benefit. 54/89 (60.7%) demonstrated bacterial co-infection, including 31/89 (34.8%) with bacteraemia (COVID, 23;Influenza, 8).ConclusionsIAPA and CAPA were not identified in this 4-year cohort, although case finding was limited by inadequate diagnostics. Timely access to fungal biomarkers compromises diagnostic testing. The incidence is likely to be low, despite the significant study limitations. We recommend prospective systematic practice of investigations and improved fungal diagnostics to better understand the burden of Aspergillosis in these patients.