Fungi and molds following lung transplantation

The landscape of fungal infections in lung transplant recipients has significantly changed over the course of time. The initial predominance of CANDIDA species has given way to the prominence of ASPERGILLUS species in the current era followed by other mold infections, namely, SCEDOSPORIUM and Zygomycetes, which are emerging as newer pathogens. CRYPTOCOCCUS NEOFORMANS is another important pathogen responsible for the morbidity in lung transplant recipients. The use of widespread antifungal prophylaxis directed against the mold infections has resulted in delayed onset of invasive aspergillosis in lung transplant recipients. In recent studies cumulative incidence rate of invasive aspergillosis was noted to be 2.4% at 12 months. Invasive mold infections in lung transplant may present as tracheobronchitis, invasive pulmonary infections, or disseminated disease. Invasive pulmonary infections are now the most common manifestations of mold infections, followed by tracheobronchitis. Pre- or posttransplant ASPERGILLUS colonization, along with preceding cytomegalovirus infections, hypogammaglobulinemia, and single-lung transplants are considered significant risk factors for invasive aspergillosis. Recently posttransplant colonization has been implicated in the development of bronchiolitis obliterans syndrome. The appropriate antimold prophylaxis strategy, by the use of either voriconazole or inhaled amphotericin, remains to be fully determined. Advances in the diagnosis and treatment of invasive aspergillosis have resulted in significant decreases in mortality. The risk factors for other mold infections such as SCEDOSPORIUM or Zygomycetes are being elucidated. Infections with these organisms, however, carry mortality up to 80%. The current article reviews the changes in the epidemiology of invasive molds and CRYPTOCOCCUS infections and other emerging fungal pathogens and highlights the controversies surrounding antifungal prophylaxis in lung transplant recipients.