Respiratory Syncytial Virus in Hematopoietic Stem Cell Transplantation and Solid-Organ Transplantation.

Respiratory syncytial virus (RSV), one of the most common causes of respiratory infections in immunocompetent individuals, can cause significant pulmonary morbidity and mortality in hematopoietic stem cell (HSCT) and less often in solid-organ transplant recipients. Early diagnosis and medical intervention prior to the progression from upper to lower respiratory tract viral involvement is essential to positively affect the clinical course. The greatest risk of disease progression from upper to lower respiratory tract disease is during the early posttransplant period for HSCT recipients, with lymphopenia being an important risk factor. Polymerase chain reaction has become the preferred method for rapidly diagnosing infection in this population because of higher sensitivity compared to traditional viral culture and direct viral antigen methods. Despite the lack of prospective randomized trials, retrospective pooled analyses have suggested that systemically delivered ribavirin (either aerosolized, oral, or IV; with or without immunomodulator therapy) can decrease the risk of progression of disease. Additionally, there are a number of clinical trials currently in process to evaluate several new agents that target RSV in the high-risk HSCT patient population.