Study on invasive fungal infections in immunocompromised patients to present a suitable early diagnostic procedure

SummaryObjectivesThe incidence of invasive fungal infections has increased considerably in recent years. The aim of this study was to present a suitable early diagnostic procedure in immunocompromised patients, using a molecular assay.MethodsFrom September 2005 to January 2007, 310 immunosuppressed patients were followed for fungal infections for a 6-month period. EDTA-anticoagulant whole blood specimens were collected prospectively once per week and stored at −20 °C until use in molecular assays.ResultsMolecular assays were positive in 55 (17.7%) patients. The etiologic agents were Candida albicans (67.3%), Aspergillus flavus (20.0%), Aspergillus fumigatus (7.3%), Candida tropicalis (3.6%), and Candida krusei (1.8%). The sensitivity, specificity, and positive and negative predictive values of PCR–ELISA with proven and probable invasive fungal infections were 84.6%, 92.7%, 75.3%, and 95.8%, respectively. The results showed that the mean clinical manifestation time was 38.96 days and the mean time of positivity of the molecular test (time of infection) was 17.69 days. A linear model for predicted infection and clinical manifestation time was found to be as follows: Y = 11.64 + 1.147X, r2 = 0.812, where Y is the time at presentation of clinical signs and X is the time of infection (positive PCR–ELISA result).ConclusionIt may be concluded that the molecular assay would help in the diagnosis of invasive fungal infections at the early stage of infection, before clinical manifestations.