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Acute Flaccid Myelitis: What You Need to Know About the Polio-Like Disease

This mystery illness primarily affects children — and strikes quickly with no known causes or treatments — leading many parents to call their pediatricians out of concern.


accute_flaccid_myelitisNormally, two cases of a disease are nothing to be alarmed about. But after the Centers for Disease Control and Prevention (CDC) raised concerns about a sudden increase in acute flaccid myelitis (AFM) in the United States this fall, two cases of the rare condition were reported in Iowa. And one of those involved a three-year-old boy in Grimes.

AFM is still extremely rare, but two reports in recent weeks double the number of cases Iowa saw in all of 2017. Taken with the national trend and media coverage, Des Moines area parents are rightfully worried.

What’s acute flaccid myelitis and why have I never heard of it?

Acute flaccid myelitis is a rare disease that affects your central nervous system — specifically your spinal cord. It works quickly and leads to temporary or even permanent paralysis. While scary, it’s still pretty uncommon. To date, only 62 cases have been reported in 2018, affecting people in 22 states. But most of them have come since August, suggesting it’s on the rise this fall.

This isn’t the first time there’s been a spike in acute flaccid myelitis. There were similar increases in AFM cases this time of year in both 2014 and 2016. While local and national media coverage has varied, the two previous cases in Iowa have landed AFM on the Iowa Department of Public Health’s watch list of temporarily reportable diseases that warrant special investigation.

“We don’t quite know what causes it, but it leads to some changes in movement and weakness in children,” says Dr. Daniel Pelzer, MD, a pediatrician at The Iowa Clinic in West Des Moines. “To this point, the medical community is leaning on a more viral cause. But officially, it’s not known.”

Should I be worried about AFM?

While AFM is rare, you have to take it seriously because it has the potential to cause long-term, disabling consequences. The disease primarily affects children — the average age of patients with AFM is four years old and more than 90 percent of cases happen to kids 18 or younger.

The exact cause of AFM is still unknown, but the disease could be linked to polio, West Nile virus and other non-polio enteroviruses. It’s most often compared to polio because the symptoms and effects are similar — paralysis being the most notable one. But unlike polio, there is no vaccine.

The other frightening fact about AFM is that it happens rapidly. Patients suddenly have weakness in their limbs, drooping in their face and eyes, difficulty swallowing or trouble talking. But there’s a wide spectrum of severity, from mild weakness to complete paralysis.

“Some of the symptoms for acute flaccid myelitis are similar to what was seen prior to the widespread immunization for polio,” Dr. Pelzer says. “But the science would suggest that AFM is very rare, and the symptoms will not be subtle. It’s very apparent that there’s something going on.”

Since the symptoms show signs of brain and spinal cord problems, an MRI is required to diagnosis AFM. And the results of the test would show issues in those specific areas.

How can I protect my child from AFM?

Prevention, prevention, prevention.

Acute flaccid myelitis is often called a mystery illness because it has no known cause. There’s no treatment either. But since AFM is potentially caused by many known viruses, you can follow the same preventative steps you would take for these other diseases.

  • Get your child vaccinated. Make sure your kid is up-to-date on all their recommended immunizations, especially polio.
  • Keep the mosquitos away. Those annoying insects aren’t swarming like they are in the summer, but they’re still around and could possibly carry the disease. Before your kids go out to play, dress them in long sleeves and spray them with insect repellant. Remove standing water to get rid of mosquito breeding grounds. Keep your children indoors around dusk and dawn when mosquito bites are most common.
  • Be diligent about the germs. “Follow standard winter protocol — washing hands and avoiding direct contact with someone with concerning symptoms,” Dr. Pelzer says. Make sure your children are washing their hands often, especially after being in close contact with others at school or daycare and in activities. You can also disinfect commonly-touched surfaces in your home to help prevent the spread of viruses.

“It’s normal to be worried, but that’s what we’re here for. So If you notice something is going on with your child, whether it’s a limb that doesn’t work right or an illness that’s causing neurological problems, you should call your pediatrician,” Dr. Pelzer says. “If your child suddenly has focal limb weakness and you’re genuinely concerned, head straight to the hospital.”

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