It affects mostly children.
The agency also said it will post case count updates on its website every week now, a change from the monthly updates it had been giving. "We recommend seeking medical care right away if you or your child develop sudden weakness of the arms or legs".
"We understand that people particularly parents are concerned", Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases, said in a here media briefing on Tuesday. In the most severe cases, AFM can cause trouble breathing and may require ventilator support.
There were 120 cases in 2014 when the disease was first detected in the United States.
Has anyone died from AFM?
The particular strain of virus might have something to do with the severity of AFM and how long its effects last.
Dr. Sumit Verma, medical director of the Neuromuscular Program at Children's Healthcare of Atlanta, said the pediatric system has seen 10 to 12 AFM cases since 2016. So far this year, there have been 62 confirmed cases in 22 states.
An illness that affects the nervous system and causes muscle weakness has been diagnosed in dozens of children around the country.
"It seems like there's been more cases since 2014 on a national level".
Cases have been reported in 22 states, including some in our area. But Messonnier cautioned that it would be "premature" to conclude that this year will be the same as the earlier years.More news: Major League Baseball investigates suspected Astros cheating in ALCS Game 1
More news: What You Need to Know About Sears Bankruptcy Filing
More news: Space crew survives plunge to Earth after rocket launch fails
"That's pretty terrifying. It is terrifying if you are a parent", Kerkering said. AFM remains extremely rare, even with the recent increase.
"(Parents) should not panic", said Dr. Michael Sweeney, a neurologist at Norton Children's Hospital and the University of Louisville.
The origin of the disease is also a mystery, but despite similarities it is not the polio virus. Health officials say they don't know what causes it, and there's no cure for it. Officials will be conducting additional analysis on this year's cases.
The CDC is investigating the outbreak. However, Messonnier said in her report, the CDC has tested every stool specimen from AFM patients, and none have tested positive for poliovirus. So, most of the doctors are in confusion and they don't know the reason of this aggressive invasion of virus with the small kids only, and not others. Figures show that the average age of a AFM patient is four.
How can people prevent AFM?
Doctors say if the cold gets worse or the child experiences weakness in limbs, he or she should see a physician. "We give them a lot of physical therapy, and they get a lot of rehabilitation". "You don't need an terrible lot of paralyzed children to make this an important problem".
Now 3 years old, Hunter has slowly recovered.
Health officials are able to confirm cases through a review of brain scans and symptoms.
The CDC referred calls to individual state health departments.
Washington Post writers Dana Hedgpeth and Justin Wm.