Invasive aspergillosis in children with hematologic malignancies

The respiratory tract is the most common system affected by aspergillosis in children with hematologic malignancies. However, Aspergillus spp. tend to invade blood vessels, resulting in systemic dissemination to multiple organs including, but not limited to, the brain, bones, liver, kidneys, and skin. Because early diagnosis and treatment are critical to the patient's outcome, a high index of suspicion should be maintained in children with hematologic malignancies who are neutropenic and have prolonged fever that is unresponsive to systemic antibacterials. Several diagnostic modalities should be used simultaneously in order to establish the diagnosis in an expeditious manner. Detailed radiographic evaluations with plain radiographs, and CT scans of the chest, sinuses, brain, and other organs should be performed as soon as clinical suspicion is raised. Detection of circulating antigens, such as galactomannan and 1,3-beta-glucan, and polymerase chain reaction appear promising in aiding in the diagnosis. A definitive diagnosis requires both a positive culture from a sterile site and evidence of tissue damage demonstrated by imaging studies or microscopic evaluations of sites of infection. Because the mortality rate is very high, empiric systemic antifungal therapy with amphotericin B, or one of its lipid formulations, should be initiated while laboratory investigations to substantiate or refute the diagnosis are continued. Surgical intervention is associated with a high mortality rate but may be of benefit in children with localized disease.