Incidence of zygomycosis in transplant recipients

Recently, a remarkable increase in the incidence of zygomycosis has been reported from institutions in the USA and Europe. The use of voriconazole for the treatment of aspergillosis and, less frequently, the use of echinocandins as empirical treatment for invasive fungal infections are thought to be responsible for the increase. In addition, an increased incidence of this infection has been observed in transplant recipients, including both haematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) patients. There are no global surveys on the prevalence or incidence of zygomycosis, but data from individual institutions and countries show that zygomycosis is an emerging infection. The increased incidence of zygomycosis most probably reflects a greater frequency of predisposing factors, such as higher numbers of patients undergoing HSCT and immunosuppressive chemotherapy. In addition, the emergence of rare pathogens as a result of the rise in the use of antifungal therapy against common species can be postulated. Further, the availability of antifungal agents with activity profiles that are more specific for selected fungi increases the necessity of identifying pathogenic fungi; the frequency of Zygomycetes infections may have been underestimated until now because therapeutic decisions did not depend on the precise identification of pathogenic fungi.