On average, the Minnesota Public Health Department sees one case a year of acute flaccid myelitis, a condition so rare that only one in 1 million Americans will be infected each year. AFM affects the spinal cord's gray matter and weakens muscles and reflexes, causing paralysis and even death.
But since mid-September, the health department has seen six cases of AFM in children under the age of 10, sparking concern. The cases were reported in the Twin Cities, central Minnesota, and northeastern Minnesota, health officials reported.
Kris Ehresmann, a health department spokesperson, told CBS News that the primary cause is viral infections. She cited AFM's telltale symptoms: sudden weakness in arms and legs, facial drooping, difficulty swallowing, sudden inability to speak.
“If you have a child that is having these kinds of symptoms, they should be seen, evaluated, immediately,” she told CBS.
People who have AFM and experience numbness or tingling should get emergency medical attention because those are signs of potential respiratory failure or neurological complications, doctors say.
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What makes AFM especially frightening is what we don’t know about it. The disease seems to predominantly affect children. The Centers for Disease Control considers AFM “a rare but serious condition” and noticed a spike cases starting in 2014—possibly related to a national outbreak of enterovirus D68, a severe respiratory illness.
But the exact mechanism by which AFM takes a foothold and slowly destroys the body's nervous system remains mysterious. Theories range from viruses to environmental pollutants to a genetic predisposition. The CDC has noticed some correlations between other neurologic conditions like polio, West Nile virus, and adenoviruses, but also notes on its website that “despite extensive lab tests, the cause of a patients AFM is not identified.”
That's small comfort for parents who are worried for their children in Minnesota and elsewhere. For now, the CDC suggests washing hands and staying up-to-date on routine vaccinations as preventative measures.