Herpes Simplex Virus and Varicella Zoster Virus in Hematopoietic Stem Cell Transplant Recipients

Patients who undergo hematopoietic stem cell transplant (HCT) have a high incidence of herpes simplex virus (HSV) and varicella zoster virus (VZV) infections, despite universal prophylaxis post-transplant. Unique risk factors, such as the utilization of aggressive conditioning chemotherapy regimens, acute or chronic graft-versus-host disease (GVHD), and decline in T-cell-mediated immunity, contribute to the high incidence of these infections post-HCT. Epidemiology, specific risk factors, and unique clinical features of HSV and VZV infections post- HCT are described in this chapter. In addition, acyclovir-resistant (ACVr) HSV infections have the highest incidence in HCT recipients. In this chapter, we describe specific risk factors, diagnostic challenges, and treatment strategies for ACVr HSV infection management.