Non-Aspergillus molds

Abstract

Non-Aspergillus molds, including Mucorales, Scedosporium, Lomentospora, and Fusarium species, are a significant cause of morbidity and mortality in heart and lung transplant recipients. These organisms have a marked propensity for angioinvasion leading to thrombosis and tissue infarction and disseminated infection. General risk factors for infection with these non-Aspergillus molds include older age, augmented immunosuppression (e.g., hypogammaglobulinemia, neutropenia, T-cell depletion), presence of endobronchial stent, and airway ischemia. Infection is uncommon, but in many cases may ensue following respiratory colonization, particularly in lung transplant recipients. Timing of infection varies, although many invasive fungal infections occur within the first year following transplantation. Diagnosis is challenging and often delayed. Imaging is recommended to localize infection and to guide sampling of infected tissue for culture and histopathology. Management of these rare molds in lung and heart transplant recipients presents a major therapeutic challenge due to intrinsic resistance patterns, delayed diagnosis, and the complex pharmacologic interactions in this population. In general, lipid preparations of amphotericin B or azole antifungals (voriconazole, posaconazole, isavuconazole) are frequently used for treatment. Investigational therapies such as fosmanogepix or olorofim are promising as future treatment modalities for some of these difficult-to-treat non-Aspergillus molds.