East Ontario Children's Hospital has confirmed that another child has been diagnosed with acute flaccid myelitis, a rare polio-like disease that causes paralysis.
Now this is the third case of a disease diagnosed in a hospital since the summer.
Very little is known about acute flaccid myelitis, but doctors have determined it is not polio, despite the same symptoms.
It includes paralysis of one or more limbs, drooping on the face and eyelids, difficulty with eye movements and swallowing, and unclear speech.
Children may also experience difficulty breathing and in severe cases may require a ventilator due to muscle weakness.
Doctors say parents should seek medical attention if their child experiences sudden weakness in parts of their body, loss of unexpected bowel or bladder control, or neck pain.
Doctors don't know what caused the disease. They also don't know why it affects especially children, or why so many new cases are reported now.
According to Health Canada, the number of cases of acute flaccid myelitis this year is now almost 70.
That's up from an average of 27-51 cases per year.