gears now to the health scare that has parents on edge. Doctors fighting enterovirus and looking for a link to paralysis in some kids. Clayton Sandell has the story. Reporter: Doctors around the country are on high alert for strange symptoms seen in Colorado. Children with serious respiratory illness now coming down with signs of paralysis. They may have trouble lifting their arm to get their fork to their mouth. And that's a muscle weakness. Reporter: There is no confirmed link, but health officials say a leading suspect is enterovirus d-68, inflicting symptoms from a cold to sere respiratory symptoms. It was in 11 states, two weeks ago, 27 states, now 47 states with confirmed or suspected cases. Kids have a difficult time breathing. You notice something is wrong. Those are reasons any parent should access care for their children. Reporter: Hospitals are on the look youth. In Kansas City -- We have three cases we are focused on that have limb weakness as a presentation. Reporter: Doctors say the Colorado patients are now getting physical therapy. The question is if any of them will have permanent neurologic damage or not. Reporter: For some, the road to recovery may be very long. For "Good morning America," Clayton Sandell, ABC news,