-- Simon Humphrey spent nine days in a Colorado hospital room fighting for his life.
Humphrey, 13, is one of hundreds of children across the country stricken by Enterovirus 68.
He later had problems moving his limbs.
"I couldn't move my legs," he told ABC News. "The muscles in my arms could barely lift the weight of my hands."
Humphrey is showing signs of improvement after the temporary paralysis. But his struggle reflects an emerging concern; young patients with respiratory infections later having trouble moving their arms and legs.
Investigators with the Centers for Disease Control and Prevention are searching for links between Enterovirus D-68 and paralysis. Nine patients at Children’s Hospital Colorado – all age 18 or younger – have experienced some level of paralysis. Four of the patients tested positive for Enterovirus D-68 but, so far, doctors have not confirmed a link between the respiratory infections and paralysis. Experts say it could take a week before conclusive test results emerge.
Six of the eight children tested were found to be positive for a rhinovirus or enterovirus, and four of those cases were found to be the Enterovirus 68. The other two cases were still pending.
Dr. William Schaffner, an infectious disease expert at the Vanderbilt University School of Medicine in Nashville, Tennessee, said it’s important for officials to understand the scope of the problem.
“In a circumstance like that, the virus actually infects the central nervous system, the spinal cord, causes injury to some of the cells, and that’s what causes the paralysis,” Schaffner said.
Dr. Larry Wolk, the chief medical officer and executive director for Colorado Department of Public Health and Environment, said the paralysis is rare but could be permanent.
“Parents ask, ‘Why? Why my child or why not my child?’” Wolk said. “And it’s a question we can’t answer because we don’t really know why some of these kids go on to develop this type of serious complication.”
Enterovirus D-68 is confirmed or suspected in 45 states. Authorities are investigating whether the virus killed a 4-year-old New Jersey boy Thursday.
Doctors are urging parents to keep a close eye on sick children.
“When your child is not acting the way you would expect with a cold symptom, that’s when you need to access care,“ Dr. Christine Nyquist of Children’s Hospital Colorado said. “Breathing difficulty and wheezing is important to deal with.”