At many centers voriconazole and caspofungin have replaced amphotericin for prevention of invasive fungal infections. Treatment with these newer agents does not always follow recommended guidelines and in our hospital, prescriptions for these drugs have increased. There were 55 stem cell transplants in the past 12 months at our leukemia and stem cell transplant center. We present the 3 patients (2 undergoing stem cell transplant) who during a 4 month interval (Jan 2005-April 2006) developed breakthrough fungemia to voriconazole or caspofungin. Patient 1: A 30 year old man with Acute Myelogenous Leukemia had fever after 20 days of neutropenia. He was not on antifungal therapy and the fever resolved with voriconazole. Twenty days later, while neutropenic on voriconazole, blood cultures grew Candida glabrata (MIC (mcg/ml): fluc 64, vori 4, casp 0.12). Patient 2: A 44 year old woman underwent an autologous stem cell transplant for multiple myeloma. After receiving fluconazole for 5 weeks she was changed to voriconazole. Blood cultures obtained 5 days later grew Candida glabrata (MIC (mcg/ml): fluc 128, vori 2, casp 0.12). Caspofungin was substituted and the fungemia resolved. She remained neutropenic on caspofungin and 3 weeks later she died of fungemia with Trichosporon asahii. Patient 3: A 28 year old woman underwent an allogeneic stem cell transplant for aplastic anemia. After 2 weeks of fluconazole, she was changed to caspofungin. Four weeks later, while neutropenic on caspofungin, a Candida species (MIC (mcg/ml): fluc >256, vori >16, casp 0.25) grew in 3 bottles of blood over 5 days. The laboratory was unable to speciate the Candida isolate. Breakthrough fungemia rates in clinical trials of voriconazole and caspofungin were low. Yet, an increasingly immunocompromised population, and indiscriminate use of antimicrobials is promoting the emergence of fungi capable of evading these drugs. Targeted use of antifungals is critical to controlling the escalation of breakthrough infections.
Full conference title:
Infectious Diseases Society of America, 44th Annual Meeting
- IDSA 44th