Sixty-two people in 22 states have been confirmed to have a very rare but serious nervous system condition that causes weakness in the arms or legs, the Centers for Disease Control and Prevention said Tuesday.
The cases of acute flaccid myelitis, or AFM, are among 127 under investigation so far this year.
The number is up from 38 cases in 16 states confirmed by the CDC last week.
The CDC did not release which states have reported probable or confirmed cases. Three children have been hospitalized in western Pennsylvania, in Allegheny County.
Health officials have seen an increased number of people across the United States with AFM since August 2014 and still don’t know the cause of most cases.
There were similar waves of the same illness in 2014 and 2016, both peaking in October.
About 90 percent of the patients have been children, and their symptoms have been most similar to those caused by certain viruses, including poliovirus and West Nile.
Some patients have recovered quickly, and some continue to have paralysis.
The CDC says it’s important to practice disease prevention steps, such as staying up-to-date on vaccines, washing your hands, and protecting yourself from mosquito bites.