Challenges in the Diagnosis of Invasive Fungal Infections in Immunocompromised Hosts

Abstract

Purpose of review The expanding population of immunocompromised patients coupled with the recognition of a growing number of different species of fungi responsible for diseases in such hosts makes the diagnosis of invasive fungal infection (IFI) a challenging task. The recent advances and challenges in the diagnosis of IFI in the setting of immunocompromised hosts are reviewed. The advantages and limitations of histopathology and the role of culture-independent methods, such as those based on the use of nucleic acids applied to fresh and formalin-fixed, paraffin-embedded sections, besides culture-and non-culture-based diagnostic methods, to obtain a timely and correct diagnosis of IFI are highlighted. Recent findings The therapeutic implications of identifying the genus and species of the fungus present in the specimen with the molecular diagnostics applied to tissue specimens are reviewed. No method alone is efficient in correctly identifying fungi and it is essential to combine the traditional histochemical staining with molecular methods to achieve a rapid and genus-/speciesspecific diagnosis of IFI. Summary We review the recent findings and challenges in the hystopathologic diagnosis of IFI in the setting of immunocompromised hosts. Non method alone is efficient in correctly identify fungi and pathologists should combine classic staining with molecular methods to achieve a rapid and genus/species fungal diagnosis.

Breakthrough invasive fungal infections: Who is at risk?

“…Non‐infectious etiologies and endemic mycoses can masquerade as bIFI and vice versa. Pulmonary or extra‐pulmonary infections from endemic fungi such as blastomycosis and coccidioidomycosis, as well as Aspergillus nodules, can mimic malignancy 7,130 . Although Aspergillus nodules are typically rounded, they can appear speculated which is a common appearance of carcinoma 131 .…”

A single-centre, retrospective study of the incidence of invasive fungal infections during 85 years of autopsy service in Brazil

“…The first diagnosis of invasive aspergillosis in this study was performed in 1996, and the incidence of aspergillosis (11.2%) was lower than that in the literature, even in the most recent years 14 , 15 , 41 , 42 . Such a low incidence may be explained by difficulties in identifying the pathogen by conventional histological methods and the low incidence of the disease until the 1990s 43 .…”

“…A total of 1853 deaths due to paracoccidioidomycosis were recorded in Brazil between 1986 and 2006, representing 51% of the total number of deaths due to fungal infections 9 – 12 . In the last three decades, there has been an important decrease in mortality from paracoccidioidomycosis in the state of Sao Paulo, probably due to increased urbanization 13 , 14 .…”

Virulence and in vitro antifungal susceptibility of Candida albicans and Candida catenulata from laying hens

“…Candida species are among the most common causes of infections, with overwhelming mortality rates in immunocompromised patients (Antinori et al 2018 ; Tscherner et al 2019 ). Candida spp.…”