Editor’s note: This story was updated on Sept. 30 with additional cases in Colorado and Virginia and comments from the Children's Hospital Colorado media briefing.
Sept. 29, 2014 -- Some children hospitalized with breathing problems caused by enterovirus D68 in Colorado, Virginia, and Kansas City have also developed unexplained paralysis in their arms and legs, officials say.
Doctors have been watching for paralysis in enterovirus patients affected by the current outbreak, which the CDC says has spread to at least 40 states.
That’s because D68 is related to the virus that causes polio, which crippled thousands of children across the United States before a vaccine was created in the 1950s. And in 2012, researchers at Stanford University reported 25 childhood cases of paralysis of an unknown cause that shared features with polio, and in some cases also started as a respiratory illness.
When enteroviruses move beyond the gut or airways, they can attack nerve cells in the spine that control movement.
“The polio virus is a professional at doing this. All the other enteroviruses are amateurs. They do it very, very, very rarely,” says William Schaffner, MD. He's an infectious disease expert at Vanderbilt University in Nashville, TN. “But D68 is a new one. It’s a bit of a different enterovirus. The question is: Could it be doing this?”
He cautions that other germs, including West Nile virus, can also cause paralysis, and it could simply be a case of double infection in this cluster of children.
“This could be just coincidental, so we can’t leap to the conclusion that enterovirus D68 is the cause of this paralysis,” he says. “It’s right at the top of our list of suspects, but we haven’t nailed it yet.”
Early in the outbreak, pediatricians said they hadn’t seen any signs that infected children were having trouble moving their limbs.
But that changed recently when Children’s Hospital Colorado reported they had a cluster of nine patients with paralysis and signs of nerve damage on MRIs.
Four of the nine children have had enterovirus D68 isolated from their airways. Tests are pending for two others. And now the CDC is also checking samples of the children’s spinal fluid for the virus.
Late Monday, in a press briefing, doctors from Children’s Hospital Colorado said they’d recently seen another case of paralysis, bringing their total to 10 patients. That child is also getting further testing to see if there’s any link to enterovirus.
In each case, the paralysis or weakness started about a week after the breathing problems. Some of the affected kids are also having trouble lifting their necks and trunks. They’re getting physical therapy to help them with daily living skills. The doctors said it’s too early to say how much movement they’ll recover.
Despite the scary symptoms, Chris Nyquist, MD, medical director of infection prevention and control at Children’s Hospital Colorado, said parents shouldn’t panic.
“Probably millions of children are being infected with enterovirus D68 across the nation and they are having simple cold symptoms,” Nyquist says. "If we find that this is an association, which we haven’t proven, this is very, very uncommon. "The CDC sent out an alert to doctors across the country on Friday telling them to report similar cases. On Monday, a spokesperson for the agency declined to say how many patients with paralysis officials are aware of across the country or when the CDC might have test results.
Mary Anne Jackson, MD, is chief of the pediatric infectious diseases section at Children’s Mercy Hospital in Kansas City, MO, one of the first hospitals to flag the surge in enterovirus D68 infections. She says they have three cases under investigation with symptoms similar to those seen in the Colorado patients.
The Virginia Department of Health is investigating one report of a child with unexplained paralysis.
Schaffner says that in many children, symptoms of paralysis will ease over time as inflammation and swelling of the tissues improves.
“But some of these illnesses can have a permanent residual paralysis, just like the old-timey polio did, because if those cells have been destroyed, there can be some residual paralysis,” he says.
There is no vaccine to prevent enterovirus D68. There are no effective treatments for the infection, either.
Hospitals rely on medications to open airways and supplemental oxygen to help kids get through the worst of the breathing problems.
So far, no deaths linked to enterovirus D68 have been confirmed, but the New Jersey Department of Health said Monday the CDC was testing samples taken from a 4-year-old with suspicious symptoms who died at home.
Right now the best way to protect kids from enteroviruses are to:
- Practice good hand-washing habits.
- Avoid close contact with people who are sick.
- Disinfect frequently touched surfaces like toys and doorknobs.