Flu cases are on the rise in Kentucky, especially in children, but so is another illness that hospitalizes between 75,000 and 125,000 babies each year.
Its an illness that can also be deadly, killing 500 a year.
Good Question: What is RSV and why is it so dangerous?
Four month old Zachary Smith is one lucky little guy.
"He wasn't eating as well as he normally did and he started having a runny nose and a slight cough," said he mother Elaine Smith a Lexington pediatric nurse.
In just a few days Zachary's condition worsened.
"When we got to the clinic he was breathing 90 times a minute," said Smith.
Zachary was hospitalized, one of thousands with an illness known as RSV.
"Its a common respiratory virus that children between the age of birth to two years can get," said Dr. Rhya Strifling with the University of Kentucky.
Dr. Strifling, a pediatrician at Kentucky Children's hospital says she's seen the number of RSV cases increase since December.
Nationwide the Centers for Disease Control says RSV accounts for one of every 10 visits to the pediatrician for little ones.
Symptoms can look a lot like a cold, very runny nose, congestion that makes it hard for babies to breathe, wheezing, coughing and often times a change in eating.
Doctors often tell parents to use a saline solution for the nose, but sometimes that's not enough.
"If they are working hard to breathe, they seem like they are in distress despite sucking out their nose, if they can't keep their oxygen levels up on their own, it they don't respond to a breathing treatment like Albuterol, they need to be admitted," said Dr. Strifling.
That's what happened to little Zachary.
"He was working so hard to breathe that it was just every ounce of effort was concentrated on trying to breathe," said Smith.
Zachary spent six days in the hospital, but is now a happy healthy four month old.
The CDC says most all children will be infected with RSV by their second birthday, in most cases the symptoms are not severe.