Neutropenia is a major risk factor for invasive fungal infections, particularly those caused by moulds, such as Aspergillus spp., Fusarium spp. and the Zygomycetes. Among neutropenic patients, these invasive mould infections (IMI) occur almost exclusively in patients with profound neutropenia (<100 neutrophils/mm3) lasting more than 10-15 days [1-3]. Empiric antifungal therapy is considered standard of care in patients with persistent or recurrent fever and neutropenia. However using fever as the sole criterion for starting empiric therapy, a significant number of patients will receive antifungal therapy unnecessarily, particularly among recipients of fluconazole prophylaxis, because persistent fever in these patients is commonly due to various factors, such as uncontrolled occult bacterial infection, viral infection, drug fever and others [4].