A young patient who suddenly developed muscle weakness after experiencing a respiratory illness has tested positive for Enterovirus D68 at Toronto’s Hospital for Sick Children, the hospital confirmed Wednesday afternoon.

The patient was one of three identified by the hospital last Friday who were exhibiting weakness that ranged from mild to full paralysis.

"One child has tested positive for EV-D68," Dr. Jeremy Friedman, an associate paediatrician-in-chief at Sick Kids, said in statement on Wednesday.

All three of the patients are under the age of 10. Friedman said of the two who tested negative for EV-D68, one has tested positive for rhinovirus, a common cold.

EV-D68 is not a new virus, but the number of children being diagnosed with it has been unusually high this year. There have been a number of cases of EV-D68 in Canada and the United States. The illness has also been linked to the death of a four-year-old boy in New Jersey.

Friedman said since last Friday, the hospital has identified additional young patients who are experiencing muscle weakness, most of whom had a preceding respiratory illness. That brings the total number of patients with muscle weakness at the hospital to six:

  • Two children who have tested negative for enterovirus
     
  • One child who has tested positive for EV-D68
     
  • One child who has tested positive for rhinovirus
     
  • Two children whose test results have been sent to a laboratory to see if their cases are linked to EV-D68. Hospital officials say their results are expected sometime next week.

EV-D68 is a virus in the Picornaviridae family, which also includes the polio virus, rhinoviruses and other enteroviruses.

Overall, the hospital says it has had seven confirmed cases of EV-D68, including the patient with muscle weakness.

Health officials at Sick Kids have previously said that most enterovirus infections cause mild cold symptoms that get better on their own. Parents are being advised to monitor their children and take them to see a doctor if lingering cold seems to suddenly get worse, or if their child suddenly develops a fever.

Public health officials are also advising parents to keep an eye on their kids’ colds if they have asthma or difficulty breathing. In addition, children who suddenly develop muscle weakness or is unable to move their limbs should seem immediate medical attention.