Health officials said AFM can start with cold-like symptoms, but that's no reason to rush over to the ER. No one knows what causes AFM, although a virus or viruses are suspected.
There is now no cure for AFM, known cause in most cases, or clear explanation for why some people who contract the enterovirus experience symptoms and others do not.
"We have not been able to find a cause for the majority of these AFM cases", Messonnier admitted.
In a few cases, it appears that the illnesses were linked to viruses, including enterovirus.
There were outbreaks of around 100 cases, nationwide, between August and October in both 2014 and 2016.
"You see your child, who likes to run and play", she said.
Some victims have been infected with viruses, but researchers have been unable to identify a single virus responsible for all cases.
"This is actually a pretty dramatic disease", she said.
Jackson, who also saw persistent muscle weakness in her patients, said she believes the CDC may be hesitant to specify the long-term effects of disease because existing studies have included only small numbers of patients.
The CDC has not traced the illness to a specific virus, but the agency said it has a variety of causes including viruses, environmental toxins and genetic disorders.
There have been 127 cases reported in 22 states so far this year, with 62 confirmed as acute flaccid myelitis, said Dr. Nancy Messonnier, head of the National Center for Immunization and Respiratory Diseases at the U.S. Centers for Disease Control and Prevention. This is the first report of potential AFM to the NDDoH.
The good news is that the complication is "incredibly rare", Messonnier said. "All of a sudden, 'Mommy I can't zip my trousers". And in very rare cases, AFM can trigger fatal neurological complications. The disease is marked by a sudden onset of weakness and loss of muscle tone in the arms and legs caused by an attack on the nervous system and spinal cord.
The last major AFM outbreak - 120 cases across 34 states in 2014 - coincided with a sharp rise in severe respiratory illnesses caused by enterovirus D68.
There is also a fourth new suspected case in eastern Pennsylvania, Nate Wardle, spokesperson for the Pennsylvania Department of Health, said Thursday.
Despite the recent spike in reported cases of AFM, Messonnier underscored that the disease is "incredibly rare" and has been diagnosed annually at a rate of less than one in a million since 2014. Since then, there have been more than 350 confirmed cases of the sickness.
To help prevent the illness' spread, the CDC advises proper hand washing, staying up to date on vaccines and using mosquito repellent to avoid bites.
"There is a lot we don't know about AFM", Messonnier said during a teleconference for reporters. There has been one AFM-related death, which happened in 2017. "So we're very lucky that he had (physical therapy) through early intervention". Some children paralyzed by AFM have eventually regained their ability to walk, but need time.