Two Whatcom County children were among eight admitted to Seattle Children’s Hospital recently with illnesses that caused sudden paralysis in an arm, a leg or both limbs.
Health officials don’t yet know the reason for the children’s mysterious neurologic illnesses, saying they are investigating whether they have a rare condition known as acute flaccid myelitis, or AFM.
The Washington state Department of Health, Seattle Children’s, and the Centers for Disease Control and Prevention are investigating the cluster of cases, all of which occurred within a month.
“At this point there isn’t evidence that would point to a single source of illness among these cases,” said Dr. Scott Lindquist, infectious disease epidemiologist at the state Health Department. “However, this investigation is just getting underway and we’re looking at all possibilities as we try to understand what might have contributed to these illnesses.”
The eight children were admitted to the hospital with a range of symptoms that also differed in severity. But all lost strength or movement in one or more of their arms or legs, state health officials and Seattle Children’s said.
“To have eight cases that could fit this syndrome cluster in such a short period of time is what the concern is,” Lindquist said Friday, Oct. 28.
The cases have not yet been confirmed as AFM, which affects the nervous system, specifically the spinal cord.
The CDC will confirm whether the cases are AFM, using lab tests and magnetic resonance imaging to search for distinctive lesions in certain areas of the spinal cord, health officials said.
Lindquist said all eight cases may not turn out to be AFM, adding that the investigation is in the early stages.
“I am not convinced at this time that they all are the same thing,” he said.
But the number of similar cases so close together was unusual and a matter of concern, Lindquist said.
The children ranged in age from 3 to 14 years. They were from four counties:
▪ three from King County
▪ two from Whatcom County
▪ two from Franklin County
▪ one from Pierce County
Three children remained hospitalized as of Friday, Oct. 28. Five have been released.
It was unknown whether the children from Whatcom County still were in the hospital. Health officials declined to release further information, citing patients’ privacy rights.
Symptoms typically include sudden weakness in one or more arms or legs, as well as loss of muscle tone and reflexes.
Other symptoms include weakness or drooping in the face and eyelids, difficulty with moving eyes, difficulty swallowing or slurred speech.
Lindquist said the classic disease associated in the U.S. with such symptoms was polio, before noting that polio wasn’t the cause for the Washington state cases.
“We’re not suspecting polio here,” he said.
The exact cause of AFM is unknown.
Many viruses and germs are linked to AFM, health officials said, including common germs that can cause colds and sore throats, and respiratory infections.
It also could be caused by mosquito-borne viruses such as West Nile or Zika.
Concerned parents don’t need to fear that they will miss the symptoms if they’re not vigilant, according to Jim Owens, pediatric neurologist at Children’s Hospital.
“It’s something that they would notice,” Owens said, referring to the weakness in arms or legs. “It’s not subtle.”
There were no cases of AFM reported in Washington state last year. There were two in 2014. Health officials said it’s rare, with fewer than one in a million people developing AFM.
Still, there has been an increase in AFM cases this year, according to the CDC.
Health officials said there have been more than 50 cases in 24 states across the U.S. as of August 2016.