AFM: "Polio-like" Illness has Affected 6 Minnesota Children

Six Minnesota children diagnosed with rare polio-like disease

Since 2014, more than 360 cases of AFM have been reported in the United States.

While fewer than 1 in a million people in the USA are diagnosed with AFM each year, the CDC is concerned about the recurrent outbreaks, especially given the mysterious nature of the illness.

While aspects of the condition are puzzling, Messacar says it's no mystery disease.

"But it won't tell us what's causing the AFM, which virus, which process, that part we still don't know", Dr. Esper says.

The other viruses such as EV-D68 and EV-A71 cause much milder disease or no symptoms at all. "This is a very rare condition", he stresses. There is no known cause or cure but it may be related to the virus that causes the common cold.

"This includes cases of meningitis, encephalitis, and acute flaccid myelitis (AFM) as well as children experiencing myoclonus (abnormal muscle jerking) and ataxia (loss of balance)".

State medical officials released a statement on the outbreak last week so that doctors can be on the lookout for more cases.

"Parents described their kids as dizzy, wobbly and having jerky movements", Herlihy said. Cases have been reported from the Twin Cities, central Minnesota and northeastern Minnesota.

Michael Osterholm, PhD, MPH, director of the University of Minnesota's Center for Infectious Disease Research and Policy (CIDRAP), which publishes CIDRAP News, said today on a WCCO radio show that so far there's no clear picture of what's causing the periodic rises in AFM cases, which has mostly occurred in children. Other symptoms are neck weakness or stiffness, drooping eyelids, difficulty swallowing or slurred speech. Most patients must be hospitalized.

"But we do know that over time, with rehabilitation therapies, numerous children can regain function".

For example, a neurologist may recommend physical or occupational therapy to help with arm or leg weakness.

It's always important to practice disease prevention steps, such as staying up-to-date on vaccines, washing your hands, and protecting yourself from mosquito bites.

Health officials said that a single cause of AFM has not been found and often no cause is found. A doctor can also do an MRI (magnetic resonance imaging) to look at a patient's brain and spinal cord, do lab tests on the cerebrospinal fluid (the fluid around the brain and spinal cord) and may check nerve conduction (impulse sent along a nerve fiber) and response.

EDITOR'S NOTE: This story was written by Maggie Fox, NBC News.