Rare, polio-like illness has now reached Children's Hospital, LHSC says

CBC News has learned that three cases of a rare, polio-like disease have presented at the London Health Sciences Centre's (LHSC) Children's Hospital in 2018, all since early September.

There were no cases of the illness in 2017, a spokesperson said in an email.

The disease, acute flaccid myelitis (AFM) is a sub-type of another rare but serious neurological illness called acute flaccid paralysis (AFP), according to Dr. Adam Kassam, a senior resident physician in physical medicine and rehabilitation at Western University.

Over time, AFM can cause muscle weakness, trouble swallowing and, in severe cases, respiratory failure, he said.

"It's still a vastly rare presentation of illness, but it does provoke some concern based on the frequency, relatively soon over the past couple of months," said Dr. Kassam.

A spokesperson for LHSC said over email that, due to privacy reasons, it cannot disclose the status of those three patients.

Incidents of the disease have increased in the U.S. this year, with more than 60 cases confirmed and another 65 currently under investigation, according to the Centers for Disease Control and Prevention.

Since September, the Hospital for Sick Children in Toronto has also seen an increase in patients with symptoms typical of AFP, namely muscle weakness and a preceding viral illness, according to associate pediatrician-in-chief Dr. Jeremy Friedman.

The Middlesex-London Health Unit says there have been no reports of AFM in London or Middlesex County, which means the patients would likely have come from other public health jurisdictions.

The health unit considers AFP a disease of public health significance, and confirmed or suspected cases of the illness must be reported as soon as possible.

'Rare but serious'

Doctors don't know what causes AFM, but Kassam said it may be related to class of viruses known as enteroviruses, which also causes polio. Although infectious diseases that target the motor nerves and spinal cord can, in theory, affect anyone, Kassam said AFM has a particular "predilection" for children.

"This is something that's relatively rare, but affects children, and so this is something we should be concerned about as a community," he said. 

Kassam said parents should watch out for symptoms including sudden weakness and an inability to move a limb. AFM usually presents in just one side of the body, and tends to target the legs more so than the arms, he said. 

There is no specific treatment for the illness, and kids who get AFM are primarily helped through physical therapy and adaptive solutions like wheelchairs or crutches once they're medically stable, Kassam said.

An email sent out to Ontario pediatricians by Dr. Friedman of the Hospital for Sick Children said treatment may include IV steroids, IVIG and/or plasmapheresis, on a case by case basis.

"If [parents] do have a suspicion about their child suffering from weakness that is unexplained, or it happened suddenly, then they should go to their doctor or go to their emergency room as soon as they can," he said.