The disease is called acute flaccid myelitis, or AFM.
The Centers for Disease Control and Prevention (CDC) is concerned about Acute flaccid myelitis (AFM), a serious condition that causes weakness in the arms or legs.
Since the first wave of AFM cases in 2014, the CDC has confirmed 386 cases of AFM.
"CDC is actively investigating AFM cases and monitoring disease activity", the agency said. "We have not confirmed the cause for the majority of these cases", the agency said. In addition, 120 cases were confirmed in 2014 between August and December. "Most AFM cases occur in the late summer and fall", but no geographic clustering has been found and there is no other "unifying factor to explain the peaks", which seem to occur every other year, she added.
Cases of a rare polio-like condition have begun turning up in some Canadian children, following reports of dozens of cases in the U.S.in recent weeks.
Officials say they haven't found the cause. "Overall, the rate of AFM over the years that it has been diagnosed which is since 2014 is less than one in a million".
"We know this can be frightening for parent", said Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, during a telephone briefing to reporters last week.
The CDC confirmed 22 cases in 2015, 149 cases in 2016 and 33 cases in 2017, although the exact cause of the condition, and who is at higher risk for developing AFM and why have not been confirmed.More news: Broncos waive backup QB Kelly
"Even with the spike of cases that we have at the moment, it's still an incredibly rare condition", Friedman said. These kids have a sudden onset of weakness.
A mystery ailment that causes severe weakness or even paralysis in children has affected hundreds in the USA over the last five years. Damage to the nervous system can be long-lasting or permanent.
The condition causes people's muscles and reflexes to weaken significantly, usually in one or more of their limbs.
"I encourage parents to seek medical care right away if you or your child develop sudden weakness or loss of muscle tone in the arms or legs", Messonnier said.
The best prevention is getting the polio vaccination, which helps protect against the polio virus.
The CDC has been clear on one thing: none of the patients has tested positive for polio.
The first case of the illness, for which there is no specific treatment or cure, was confirmed in MA in August, according the department.
There is no long-term prognosis for people who get infected with AFM.