Medical researchers fear that more children will develop paralysis from a mysterious polio-like illness that has struck every two years since 2014.
When a cluster of children in the U.S. developed unexplained paralysis in 2014, doctors hoped the outbreak was a freak event. Then, in 2016, more people came down with the same set of symptoms. This year, AFM struck a record 165 people, the majority of them young, previously healthy children
Many experts, including Greenberg, say the agency has been slow to name viruses as a probable cause.