Bone-marrow transplantation and related infections.

The utility of bone-marrow transplantation (BMT) in the treatment of malignant and hematopoietic diseases is increasing. Additionally, refinements in the use of peripheral stem cells, unrelated marrow donors, and management of immunological complications of graft-versus-host reactions have contributed to the increase in the number of BMT performed each year. At the same time, the spectrum of infections associated with BMT are evolving. Improved prophylactic measures are decreasing the severity and frequency of bacterial, yeast and cytomegalovirus and Herpes simplex viral infections. However, other viruses are now emerging as pathogens. Common community-acquired respiratory viruses have caused significant morbidity and reports of human herpes virus-6 (HHV-6) infections in diffuse pneumonia raise the specter of additional previously unrecognized viral pathogens. Most alarming however, is the apparent increase in infections caused by filamentous fungi, which appear to develop despite anti-fungal prophylaxis. Improvement in preventive and treatment options for fungal disease is crucial to continued improvement in the outcome of BMT recipients.