Milwaukee \u00e2\u0080\u0094 A deadly respiratory illness that\u0027s spreading rapidly this year can be very dangerous for infants and young children. Every year in the U.S., about 57,000 kids under age 5 need to be treated in hospitals for respiratory syncytial virus, also known as RSV, according to the U.S. Centers for Disease Control and Prevention. It can also lead to as many as 500 deaths per year.The flu-like virus has babies filling a Milwaukee intensive care unit. That includes Robin and Sarah Komassa\u0027s son Colton, who was diagnosed with RSV just before Christmas."We were scared, and confused, like we had just gone to the doctor so we didn\u0027t expect this," said Robin Komassa.Colton was admitted to Wisconsin Children\u0027s, where CBS News had to interview Dr. Michael Meyer in the hallway because the ICU was full."For you and I, RSV is a common cold virus. For little kids, because their airways and their passages are so small, you fill that up with secretions, suddenly it\u0027s very difficult to breathe," Meyer said.Flu season comes early this year due to unexpected virusEarly flu season prompts hospitals to take extra precautionsSymptoms include a runny nose, cough, fever, wheezing and a decrease in appetite.\u00a0The CDC and state health department don\u0027t track severe RSV like they do with the flu. But besides Wisconsin, hospitals in at least four other states \u00e2\u0080\u0094 Michigan, Kentucky, Ohio and New York \u00e2\u0080\u0094 have reported a surge in cases. Paisley Mitchell, who is three weeks old, is recovering from RSV in the ICU at Arkansas Children\u0027s Hospital, which has seen 100 more patients than it had by this time last year.After a week in the hospital, Colton is now recovering at home. Unlike the flu, which can spread through particles in the air, RSV is transferred by contact, which is why washing your hands and cleaning surfaces, including your phone, is so important.