During the colder months, we often hear about ways to avoid the flu. Another respiratory illness that can have serious effects on young children and the elderly is Respiratory Syncytial Virus, or RSV.In the United States, RSV is the most common cause of bronchiolitis and pneumonia in children less than a year old. Of those infected with RSV, a small percentage of children develop severe respiratory illness. In addition to young children, adults with compromised immune systems and those 65 and older are also at an increased risk for RSV.A person with RSV may cough, sneeze and have a runny nose, fever, and decreased appetite. Wheezing may also occur. Very young infants may be irritable, have decreased activity and may exhibit breathing difficulties. If your child or an adult who is vulnerable to respiratory illness has the symptoms of RSV, call your doctor immediately. The physician will assess the symptoms and decide whether hospitalization is necessary.To avoid RSV, ask people to cover their coughs and sneezes and to wash their hands.