At the end of last summer a common respiratory virus known as enterovirus D68 began to make the rounds in the U.S., landing more than 1,000 children in hospitals. As the outbreak picked up steam, physicians began to notice an alarming trend. Some children diagnosed with enterovirus D68 also developed sudden partial paralysis.
Medical experts have been slow to link this symptom directly to the virus until tests and research prove that there actually is a connection. But a new genetic analysis published Monday in the journal Lancet Infectious Diseases indicates that the illness may actually be caused by a mutated strain of enterovirus D68 that's akin to polio. The strain, known as B1, first emerged four years ago.
"Last fall we saw some severe respiratory illnesses. Some kids needed oxygen or to be on a ventilator in the hospital," medical contributor Dr. Holly Phillips told "CBS This Morning." "But even more alarming, about 100 kids developed a form of paralysis and weakness in their arms and legs. It's a called acute flaccid myelitis."
Between August 2014 and January 2015 there were 1,153 reported cases of enterovirus D68 in the U.S., according to the Centers for Disease Control and Prevention. The virus was detected in 49 states and caused 14 deaths. Most patients diagnosed were children and teenagers. Out of the more than 1,100 cases of enterovirus, 115 of the patients developed weakness in their extremities, or partial paralysis. The median age of children diagnosed with cute flaccid myelitis was 8 years old.
The new study involved 25 children who developed partial paralysis. Among the group, 16 lived in California and 9 were in Colorado. Phillips says this paper gives us "the strongest evidence yet that the virus is in some way responsible."
"The report also found that the majority of the kids who developed paralysis after several months had not recovered completely," said Phillips. "They still had the weakness in their limbs. So there are treatments but clearly they are not effective enough. The other alarming thing is enterovirus usually just causes common cold symptoms. But for instance, polio is also an enterovirus, so we know they can cause paralysis, and this new strain may be something emerging that's responsible."
However, it's still unclear to physicians and researchers why some children developed paralysis and others did not. With two siblings enrolled in study, one had only a runny nose but the other developed paralysis of both of her upper limbs, suggesting that other factors in the children's biology also played a role.
Phillips said last year's outbreak most likely won't be the last, so it's important for parents to be aware of their child's risk. "We might see this remerge in the fall," she said. "It's just a reminder not to completely ignore symptoms of the common cold, particularly if your child has trouble breathing. Don't hesitate to go the ER."