Antifungal prophylaxis in hematopoietic stem cell transplant recipients

Efforts at preventing and treating fungal infection in hematopoietic stem cell transplant (HSCT) recipients must take into account the types of infections likely to be encountered during the different risk periods in hosts with different underlying risks. Given the emergence of molds as prevalent pathogens and the long duration of risk in allogeneic HSCT recipients, optimal antifungal prophylaxis would consist of treatment that can be given over a prolonged period and that would provide both anti-Candida and anti-Aspergillus activity. Optimal empiric therapy would consist of a broad-spectrum agent in the absence of more sensitive and specific methods for microbial diagnosis. Fluconazole (Diflucan) is currently the standard prophylactic agent for candidiasis, although mold-active agents and alternative strategies for polyene administration are being investigated. The gold standard for empiric therapy is currently a polyene antifungal, yet an increased appreciation for amphotericin B-resistant yeasts and molds, and less toxic mold-active alternatives, might lead to the use of other compounds in the future. The recent development of multiple alternatives emphasizes our need to establish treatment algorithms that consider both the likely pathogens and potential toxicities.