Viral Infections in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Literature Review

Hematopoietic stem cell transplant (HSCT) recipients are at an increased risk of bacterial, viral, fungal and parasitic infections. Past exposures to infections, the degree of immunosuppression, prolonged neutropenia and presence of graft versus host disease (GVHD) are some of the factors which make HSCT recipients more susceptible to infections. Viral infections have emerged as a major challenge causing high morbidity and mortality in stem cell transplant recipients. Myeloablative conditioning regimens and GVHD prevention strategies which may delay immune reconstitution and serologic status of donors and recipients affect the incidence of viral infections. Community-acquired respiratory and gastrointestinal viral infections like respiratory syncytial virus (RSV), rhinovirus, adenovirus, influenza, norovirus and reactivation of latent viruses like herpes simplex virus (HSV), cytomegalovirus (CMV) are some of the important pathogens increasing the morbidity and mortality in transplant recipients. Clinical manifestations range from asymptomatic carriage to severe disease. Due to lack of effective agents to treat viral infections and emerging resistance patterns, preventive and prophylactic strategies are valuable. Our review article provides an overview of commonly encountered viral infections and their management in an allogeneic stem cell transplant setting in the adult age group.