Zygomycosis and other rare filamentous fungal infections in solid organ transplant recipients

Abstract

Fungi cause severe infections in solid organ transplant (SOT) recipients. Recently, a shift towards non-Aspergillus filamentous fungal infections (nAFFI) was noticed. In a series of 2878 SOTs (kidney, pancreas, islets, liver, heart, lung, and bowel) performed between January 1995 and December 2006 at the Innsbruck medical university, eleven cases of nAFFI were diagnosed. The encountered species included Zygomyzetes (n = 8), and Alternaria alternate, Pseudallescheria boydii, Trichoderma spp. (one each); there were three liver and three heart, one intestinal, pancreas, lung, bilateral forearm and renal recipient each. Five patients died from nAFFI (zygomycosis: 4, Pseudallerichia boydii: 1); four were diagnosed postmortem. In five cases infection was surgically treated in combination with antifungals. Risk factors for nAFFI were renal failure (73%) and intensified immunosuppression (73%); two cases were associated with post-transplant lymphoproliferative disorder, one with graft versus host disease. An increase in the incidence of nAFFI was observed parallel to introduction of caspofungin and voriconazole (three cases until 12/2003, seven cases thereafter). NAFFI are increasingly found in SOT recipients. If diagnosed in time, the outcome seems acceptable. Intensified immunosuppression and exposure to antifungals not active against zygomycetes may be risk factors. Surgical therapy may play an important role in these infections.