Hematopoietic Stem Cell Transplantation: An Overview of Infection Risks and Epidemiology

The dynamic nature of damage to host defenses and restoration of host defenses and immunity after HSCT

The risk for infection and the spectrum of infectious syndromes differs by type of transplant, type of conditioning regimen, type of stem cell graft, and type of posttransplant therapies and whether or not certain posttransplant complications occur, such as GVHD. Table 1 illustrates some of these considerations. The risk of infection can be divided into three time intervals. The time periods and infectious risks are illustrated in Table 2.

Early, before engraftment, the major compromises in host

Prevention and treatment approaches

Management strategies are beyond the scope of this article. Consensus guidelines for infection prevention for HSCT patients were first published in 2000⁵¹ and recently have been updated.¹ Evaluation and management guidelines for neutropenic fever have been published.3, 4 Prevention and treatment guidelines for Candida and Aspergillus have been published.52, 53 Discussions of CMV treatment have been published.49, 54

Summary

HSCT has become a common treatment of bone marrow failure and certain malignancies. Types of transplant, including types of stem cells and conditioning regimens vary, impacting the magnitude and duration of primary risk periods. Risks for infections caused by numerous bacterial, viral, and fungal pathogens can extend over a long period of time, dictating preventative strategies and differential diagnoses.