what is rsv virus
Article Body. The respiratory syncytial virus (RSV) is a major cause of infections of the breathing passages and lungs in infants and young children., It is one of many viruses that can cause bronchiolitis (an infection of the bronchioles, the small breathing tubes of the lungs).rticle Body. The respiratory syncytial virus (RSV) is a major cause of infections of the breathing passages and lungs in infants and young children., It is one of many viruses that can cause bronchiolitis (an infection of the bronchioles, the small breathing tubes of the lungs).