DENVER (CBS4) — Human enterovirus 68 is responsible for dozens of children across Colorado ending up in intensive care units. It mimics the common cold, but within hours those affected can become severely ill. Parents say that within hours of developing cold symptoms, their children were gasping for air and placed on ventilators.

Thirteen-year-old Will Cornejo said, "I remember thinking I was going to die. Yesterday I felt like I couldn't breathe at all." He remains on oxygen in intensive care, but his parents say he is improving. "He was white as a ghost, his lips were blue, he was completely unconscious at that point," said his mother, Jennifer Cornejo. "Sheer terror," said his father, Matt Cornejo. They called 911 and he had to be airlifted to the hospital. "At that point we weren't sure he was going to make it," Jennifer said.

At Rocky Mountain Hospital for Children, Dr. Raju Meyappan said the virus had not been seen in Denver previously. He is concerned by how quickly it can become life-threatening, especially in children with mild asthma. "The onset of symptoms was very rapid, usually within hours," Meyappan said. Will is still weak, but his mother can tell he is getting better. DENVER — A rare virus has sickened dozens of Colorado children, filling intensive care units around the state, CBS Denver reports. Human enterovirus 68 has the same symptoms as the common cold, but within hours those affected can become severely ill; parents say children who initially seem to have a cold can be left gasping for air and placed on ventilators. Since EV‑D68 is a virus, antibiotics don’t work; doctors can only treat symptoms, helping kids breathe and keeping airways open.

"I remember thinking I was going to die," said 13-year-old Will Cornejo. "Yesterday I felt like I couldn't breathe at all." Will is still on oxygen and in intensive care, but his parents say he's improving. "He was white as a ghost, his lips were blue, he was completely unconscious at that point," said his mother, Jennifer Cornejo. His father, Matt Cornejo, said they felt "sheer terror." "It was the scariest moment of my life because he was surrounded by five paramedics and a police officer," he said. "It's kind of shocking to be a few minutes away from possibly dying to being a normal eighth grader. We're very relieved." Will had to be airlifted to the hospital. "At that point we weren't sure he was going to make it," said Jennifer. In the ICU at Rocky Mountain Hospital for Children, Dr. Raju Meyappan said the virus hadn't shown up in Denver until now and he is seeing how quickly it becomes life-threatening, especially in children with mild asthma. "The onset of symptoms was very rapid, usually within hours," Meyappan said. Since human enterovirus 68 is a virus, antibiotics don't work; doctors can only treat the symptoms, helping kids breathe and trying to keep their airways open. Will is still weak but his mother can tell he is getting better. "He's texting, he's doing Instagram," said Jennifer Cornejo. "A lot of people were wondering if I died," said Will. "And I wanted to make sure that they didn't think that, so I started texting people telling them I wasn't." "It's kind of shocking to be a few minutes away from possibly dying to being a normal eighth-grader," said his father. "We're very relieved." Will Cornejo is recovering at Rocky Mountain Hospital for Children at Presbyterian/St. Luke's Medical Center; his parents, Jennifer and Matt of Lone Tree, were with him. Children's hospitals in Denver are experiencing an alarming spike in a severe respiratory illness—especially among very young children and those with asthma—that may be caused by an uncommon viral pathogen. Officials at Children's Hospital Colorado said they have treated more than 900 children since Aug. 18 for severe respiratory illness and admitted 86 to the hospital. "We've been seeing a very high volume in our ER, ICU and among hospitalized patients. The hospital is very, very full," said Dr. Christine Nyquist, a pediatric infectious disease physician. "Kids are getting the virus and having asthma complications." The suspected agent is human enterovirus 68, a rare virus associated with respiratory illness and related to rhinovirus, which causes the common cold, according to the Centers for Disease Control and Prevention. Samples sent to confirm whether it is enterovirus 68 have not yet produced a definitive answer, and similar outbreaks are being investigated in other cities, including confirmed cases in Kansas City, Mo. At Rocky Mountain Hospital for Children at Presbyterian/St. Luke's Medical Center in Denver, 13-year-old William Cornejo, a moderate asthmatic, was one of five children physicians put on ventilators this week after his mild cold developed overnight into a life-threatening illness. "Tuesday evening he had a little cold," said his mother, Jennifer. "He's a pretty moderate asthmatic." On Friday he was recovering at the hospital. "He'd never gone to the hospital for it since he was 2. I just never dreamed that we needed to go to the hospital," his mother said. After three treatments inhaling albuterol (the medicine used to prevent and treat wheezing, shortness of breath, coughing, and chest tightness), William wasn't any better, his mother said. She was trying to reach his doctor when she noticed he was unresponsive. "His lips were blue. He was white as a ghost," Cornejo said.