When 13-year-old Billy Sticklen woke up the morning of Sept. 24, he discovered he couldn’t lift his arms above his chest. Within days his paralysis had progressed to the point where he could only move his hands and feet.
Now, with intensive physical therapy, he’s been making steady progress, moving from a wheelchair to a walker, and just days ago to walking with a cane.
Researchers once thought they might have an explanation for why this Joplin, Mo., boy and more than 100 other children from across the country have developed this poliolike paralysis since August.
But as they collect more evidence, the cause has become less and less certain.
“In fact, it’s a medical mystery,” said Mary Anne Jackson, chief of infectious diseases at Children’s Mercy Hospital.
Jackson and other doctors at Children’s Mercy were among the first in the nation to recognize that a virus called enterovirus D68, or EV-D68, once considered rare, was causing an outbreak of often severe respiratory illnesses among children last summer. Since August, the Centers for Disease Control and Prevention has counted more than 1,100 confirmed EV-D68 cases nationwide, almost all among children, many who had a history of asthma. It’s possible that millions of kids with milder symptoms also became ill.
“It was the largest outbreak of its type ever reported in the world,” Jackson said.
About the same time that EV-D68 was sweeping the nation, poliolike cases started appearing among children, first in Colorado and then in 33 other states.
Researchers suspected a link between EV-D68 and the paralysis because there were initial signs that some of the paralyzed children had been exposed to the virus. EV-D68 is a distant cousin of the polio virus.
But as researchers have sifted through the evidence, they haven’t been able to establish that connection.
“Today, there is no association” between EV-D68 and the paralysis, Jackson said. “We just don’t have any evidence that these two things go together.”
Jackson wouldn’t say that EV-D68 has been ruled out entirely as a cause, but research into these paralysis cases has broadened considerably.
Billy Sticklen’s case suggests just how easy it might be to look at EV-D68 as a suspect.
Over Labor Day weekend, he and two of his older siblings came down with respiratory illnesses. About two weeks later, he began experiencing headaches, fever and neck pain. His doctor diagnosed viral meningitis. When paralysis set in, Billy was taken by ambulance to Children’s Mercy, where he stayed until Christmas Eve.
As it turned out, Billy never had EV-D68. Neither did the two other paralysis cases that Children’s Mercy has treated. Of the more than 300 confirmed EV-D68 cases at Children’s Mercy, none ever developed paralysis or other neurologic symptoms.
A CDC report earlier this month on the paralysis cases across the country said that some of the patients have tested positive for EV-D68, but others have tested positive for a variety of other respiratory and cold viruses. And among patients whose spinal fluid has been tested, none showed signs of EV-D68.
“The specific causes of this illness are still under investigation, and causal relationship to EV-D68 has not yet been substantiated,” the CDC said.
Billy Sticklen isn’t concerned that his illness remains a mystery. On the contrary.
“I think it’s kind of cool,” he said Wednesday evening before getting into the Children’s Mercy physical rehabilitation pool for a swimming workout. “No parents want their kids to be a statistic, but I think it’s cool. It’s going to make a great story.”
His mother, Dawn Sticklen, has seen her son’s optimism and confidence grow as his condition continues to improve.
“That put our mind at ease, as well,” she said.
Although only one of the children who’ve suffered the paralysis nationwide has made a full recovery, about two-thirds of the children so far have seen improvement in their condition, according to the CDC.
Jackson and other Children’s Mercy researchers are continuing to examine the mysteries of EV-D68 and the poliolike illnesses.
The hospital is collaborating with the CDC to look at blood serum from nearly 500 toddlers, children, teens and adults obtained in 2012, before the EV D-68 outbreak, to look for antibodies to the virus. This may show whether EV-D68 was circulating to any large extent before the outbreak.
Children’s Mercy doctors also are going back over several years of brain and spinal cord scans to look for evidence of the kind of neurological damage the paralysis causes. That damage can be hard to detect unless a doctor is looking for it specifically.
“The suspicion that I have is that there are going to be a number of viruses implicated” in the paralysis cases, Jackson said.
Jackson said research triggered by EV-D68 and the paralysis cases could eventually lead to better ways to diagnose viral infections and to new drugs or vaccines.
“This is just the beginning of the story,” she said.