PHILADELPHIA _ At first, it seemed like just a bad cold, with a fever that came and went.
Then one day, when Scarlett Camburn woke from her nap, the Havertown, Pa., toddler was unable to move her right arm.
Panicked, parents Andrea and Chris Camburn rushed the little girl to an urgent care center in King of Prussia operated by Children's Hospital of Philadelphia, and from there to the hospital's emergency room in West Philadelphia. X-rays showed that Scarlett, a few days shy of her second birthday in August 2016, had no broken bones. But an MRI on a future visit revealed an alarming sign: damage to her spinal cord.
The Camburns would soon learn that Scarlett was among dozens of children around the country that year whose arms or legs suddenly went limp _ evoking memories of polio, a scourge eliminated in the United States decades ago.
One of those children was Chase Kulakowski, of Dyer, Ind., age 15 months. Same pattern: had a cold, woke up from a nap, couldn't use his right arm.
"His arm was totally limp," said his mother, Jessica.
The inflammation in Scarlett's spinal cord eventually was attributed to a virus, called enterovirus D68, that had infected many of the other children. But for some patients, including Chase, no virus _ or other cause _ was found.
This fall, it's happening again. Last week, the U.S. Centers for Disease Control and Prevention said it had confirmed 72 cases of sudden muscle weakness or paralysis so far in 2018, including six in Pennsylvania and three in New Jersey.
The disease is often referred to as mysterious, given that some victims are found to be infected with D68 while others are not, and officially, the CDC says the cause for most cases remains unknown. But a core group of academic researchers tracking the disease is fairly certain that the virus, which can be hard to detect, is the primary culprit.
They're just not sure what to do about it.
And they are worried it could get worse.
