Invasive mould infections in intensive care units: Epidemiology, microbiologic diagnosis and antifungal resistance

Abstract

Invasive fungal infections present with a rising incidence and high morbidity and mortality rates. Among these infections are those due to moulds which draw particular attention per the diagnostic difficulties and higher mortality rates. While a relative decrease is observed in mortality rates regarding the use of prophylactic, empirical or preemptive antifungal regimens, there is a tendency of increase in antifungal resistance rates. Furthermore, due to increase in number of cases with immunosuppression, infections caused by rare and emerging moulds are now more frequently observed. Breakthrough infections, nosocomial infections, and infections due to risk factors other than immunosuppression are also a clinical concern.  Diagnosis of invasive mould infections requires a multidisciplinary approach with clinical, radiological, histopathological and microbiological data. However, nonspecificity of clinical signs and radiological findings and difficulties in differentiation of infection and colonization are major problems in patients with invasive mould infections in intensive care units. Limited availability of routine microbiology laboratories with adequate facilities in mycological diagnostics and problems in specificity and sensitivity of diagnostic tests for intensive care unit patients result in further difficulties in diagnosis of these infections. In this review article, epidemiological data and microbiological diagnostic methods for invasive mould infections in intensive care units were reviewed per the published reports and the recommendations of current guidelines. Finally, antifungal resistance and clinical impact of resistance were discussed.