Advancements in early diagnosis and the introduction of effective agents
have improved the rates of response of aspergillosis to primary
antifungal therapy. These changes allow the subsequent continuation of
cytotoxic chemotherapy and/or performance of hematopoietic stem cell
transplantation in an increasing number of patients with hematological
malignancies. These developments have increased interest in secondary
prophylaxis of aspergillosis, because the resumption of myelotoxic
chemotherapy in these patients is associated with high rates of relapse
of this opportunistic mycosis in the absence of prophylaxis. However,
the risk factors for relapsing invasive aspergillosis and the strategies
for reducing risk are not well defined. Furthermore, differentiating
aspergillosis relapse from reinfection with a new Aspergillus isolate is
problematic when using the available laboratory tools. We summarize the
existing knowledge regarding the pathogenesis of, risk factors for, and
natural history of relapsing invasive aspergillosis and review the
limited data regarding the role of secondary antifungal prophylaxis
