a paramyxovirus (see myxovirus) that causes infections of the nose and throat. It is a major cause of bronchiolitis and pneumonia in young children. In tissue cultures infected with the virus, cells merge together to form a conglomerate (syncytium). RSV is thought to have a role in cot death. Vulnerable children can be treated with ribavirin, but most children just require supportive measures.
Medical dictionary. 2011.