New Virus Related To Polio Caused Mysterious Childhood Paralysis In California Kids

SAN FRANCISCO (CBS SF) -- A new strain of virus has emerged that can leave one patient virtually unharmed after infection and leave the other paralyzed for life.

Researchers with the University of California San Francisco announced Monday they have found the genetic signature of enterovirus D68 (EV-D68) in half of California and Colorado children diagnosed with acute flaccid myelitis--a medical term describing sudden and unexplainable muscle weakness and paralysis.

The group looked at cases from 2012 to 2014, related to a national outbreak of respiratory illnesses from the virus last fall.

The paralyzing symptoms occurred in only a small number of the children who were sick. In some cases, among two siblings who both had the virus, only one developed the paralysis.

"This suggests that it's not only the virus, but also patients' individual biology that determines what disease they may present with," said Charles Chiu, MD, PhD, an associate professor of Laboratory Medicine and director of UCSF-Abbott Viral Diagnostics and Discovery Center.

"Given that none of the children have fully recovered, we urgently need to continue investigating this new strain of EV-D68 and its potential to cause acute flaccid myelitis," Chiu said.

Of the children studied, 16 were from California. 80 percent of the children all came down with an upper respiratory infection about six days before the spinal cord inflammation and resulting paralysis began.

It is not clear at this point whether the children will regain the ability to move their affected limbs. Many report being able to feel, but not move parts of their bodies.

The new strain of D68 is known as "B1." It emerged four years ago and had mutations similar to polio. Polio is in the same biological genus, which is one taxonomic level up from species.