My 9-month-old niece was just hospitalized with RSV. We know nothing about this. Could you please explain it?
The straightforward answer to your question is that RSV, which stands for respiratory syncytial virus, is a virus notorious worldwide for causing common cold and respiratory symptoms, especially in the winter and early spring (in the US). Not only does this common virus spread easily from person to person by direct or close contact, but it can also survive on hands and surfaces. Once someone is infected with the virus, it may take anywhere from two to eight days for symptoms to show up. In other words, RSV is a very common virus that causes very common respiratory and cold symptoms and infects just about everyone by the age of 3. These facts naturally lead people to question just why this particular virus deserves the special recognition it gets. After all, how many other common cold viruses do you know by name?
Unfortunately, what you have discovered with the hospitalization of your 9-month-old niece is that RSV has the potential to cause more serious symptoms in infants and others with certain risk factors. Those at greatest risk include infants born prematurely, those under 6 months during RSV season, and those who have underlying conditions such as heart or lung problems, asthma, or weakened immune systems. While you or I (or older children) tend to only experience more mild upper respiratory symptoms (such as a clear runny nose), infants and young children are more likely to experience lower respiratory infections such as wheezing, bronchiolitis, or pneumonia. In fact, RSV is the most common cause of lower respiratory tract infection in children younger than a year.
While I don't know the details of your niece's circumstances, I can tell you that her hospitalization is not unique. RSV is thought to be responsible for up to an estimated 120,000 pediatric hospitalizations a year. In some instances, an infant's poor feeding, fever, dehydration, irritability, and/or lethargy may warrant admission for closer observation and to make sure she gets enough to drink to avoid dehydration. Others may experience enough difficulty breathing to require hospitalization and treatment.
I certainly hope that your niece's RSV infection follows the typical course and resolves on its own, just like most other common colds. In the meantime, be aware that anyone who has RSV is typically considered contagious for up to eight days (but as long as a month for young infants) after symptoms appear. Remember to try and avoid contact with "contaminated" items such as mucus and used tissues when possible, commit to regular hand washing with soap and water—especially after coming in close or direct contact—and be aware that disinfection of frequently touched and known-to-be contaminated surfaces can help limit the spread of RSV (not to mention other germs).