Etiology of invasive and subcutaneous fungal infection: Report from the Portuguese laboratory network

The epidemiology of invasive fungal infections has been changing with the emergence of new etiological agents. In order to better understand the epidemiology of these infections in Portugal, in 2013 the National Network for Laboratory Surveillance of Invasive and Subcutaneous Fungal Infections was made up, comprising 14 hospital laboratories. The following were included for study: i) cases of invasive fungal infection (IFI) by filamentous / dimorphic fungi, ii) cases of probable IFI, according to the criteria established by EORTC / MSG 2008, and iii) cases of subcutaneous fungal infections. Yeast and Pneumocystis jirovecii infections were not included. Participating laboratories ensure the communication of IFI cases to the Reference Laboratory, sending biological or isolated samples, accompanied by a survey containing demographic, laboratory and clinical assessments of patients with suspected fungal infection. Between June 2013 and May 2020, 76 cases were included, distributed as follows: proven IFI (n = 19), subcutaneous infection (excluding endemic fungi) (n = 25); infection by endemic fungi (n = 11), totaling 72.3% of proven deep fungal infections (n = 55), the remaining 27.6% corresponding to probable IFI. It was possible to identify the etiological fungal agent in 96% of the included cases. The genus Aspergillus was the most frequent fungal genera detected being more frequent in the proven and probable IFI. Aseptate fungi of the Mucorales order corresponded to 9.2% of infections, and infections caused by dimorphic endemic fungi represented 14.5% of the total cases. In 10 cases, no positive culture was obtained and the identification of the etiological agent was achieved by panfungal PCR followed by sequencing or though targeted PCR (Aspergillus / Mucorales). Regarding the risk factors for fungal infections, in 81.6% (n=62) of cases, the presence of one or more risk factors for fungal infection was reported. Despite the small number of cases, results allowed perceiving the high diversity of species and the main associated risk factors associated with the diagnosed IFI. Knowledge of the epidemiology of fungal infections is important to improve their diagnosis and treatment.N/