As August approaches, the CDC is asking health care professionals to be on the lookout and report any suspected cases of AFM (Acute Flaccid Myelitis), a paralyzing illness resembling polio, as cases may peak during this time.
Last year a total of 233 cases were confirmed in 41 states. This year 11 have been reported and an additional 57 cases are being investigated. Cases have been reported in California, Maryland, Nebraska, North Carolina, Pennsylvania, Texas, Utah and West Virginia this year.
Image above from CDC
Last year, California, Colorado and Texas appeared to be the worst hit with 15, 16 and 31 cases respectively. Experts are urging states to report any cases of suspected AFM as the above map could be an under-representation of true numbers.
On their website, the CDC reports the following:
Most of the patients with AFM (more than 90%) had a mild respiratory illness or fever consistent with a viral infection before they developed AFM.
Viral infections such as from enteroviruses are common, especially in children, and most people recover. We don’t know why a small number of people develop AFM, while most others recover. We are continuing to investigate this.
These AFM cases are not caused by poliovirus; all the stool specimens from AFM patients that we received tested negative for poliovirus.
Most patients had onset of AFM between August and October, with increases in AFM cases every two years since 2014. At this same time of year, many viruses commonly circulate, including enteroviruses, and will be temporally associated with AFM.
Most AFM cases are children (over 90%) and have occurred in 48 states and DC.
The “48 states” refers to cases since 2014. 90% of the cases occurred in children under the age of 4.
The age range of children affected appear to be 3-14. A 6-year-old boy in Washington State died in 2016 and was the first death to be linked to this mysterious illness. His parents reported he had felt ill, became dizzy and within hours suffered swelling in the brain and paralysis. Despite medical efforts, he passed.
In 2018 parents of two children who died from AFM accused the CDC of hiding their deaths.
Although the exact cause of AFM is unknown, health experts are considering a variety of possibilities. They have actually been investigating this since 2014 when reports of AFM began to surface across the United States.
What is AFM?
AFM stands for Acute Flaccid Myelitis. It’s a condition that occurs suddenly, causing inflammation of the brain and spinal cord, causing loss of muscle tone and reflexes. Although limb weakness is the primary symptom, patients could also exhibit slurred speech, facial drooping, and in serious cases inability to breath due to paralysis of the respiratory muscles. Mild cases appear to resolve but serious cases can cause residual paralysis or death. Children appear to be more affected than adults.
What causes AFM?
Although health officials do not know for certain, due to its rapid onset, a pathogen such as a virus seems highly likely. With the 2013-2014 outbreak, some of the cases tested positive for enterovirus (EV-D68), but it is not conclusive whether this was the exact cause or just coincidentally found in the patients tested.
Some postulate a combination of viruses may be a factor or an autoimmune disease. Although Guillain-Barre syndrome causes acute limb weakness and paralysis when the immune system begins attacking the nervous system, the report that many individuals feel feverish or ill prior, seem to point to a pathogen as the primary cause although the latter is not being ruled out. Virus families such as enterovirus (including polio and nonpolio enterovirus), adenovirus (causing respiratory and GI illness) cocksackieviruses and flaviviruses (including West Nile) have been suspected.
How common is AFM?
Per the CDC, acute flaccid myelitis is rare (less than 1 in a million cases) however currently they report 570 cases have been confirmed since the outbreak began in August 2014.
How is it diagnosed?
Medical professionals look at a variety of factors.
History: how the paralysis/loss of muscle tone began and which limbs did it affect first
Laboratory tests and CSF (cerebrospinal fluid) testing: to look for signs of infection
MRI of the brain: which may show gray matter involvement in a case of AFM.
Is there a treatment?
There is no standard treatment that has been proven effective, however depending on the severity of the symptoms, health professionals can consider a variety of options including steroids, IVIG, interferon, antivirals and supportive measures. Some physicians are using “nerve transfers”, similar to a transplant, to help children regain control of their limbs.
Is there a vaccine?
No. Until they can identify the exact cause, or causes, health officials cannot create a vaccine.
How does one avoid getting AFM?
If we assume it’s a pathogen causing the illness, avoiding contact with sick individuals, being up-to-date on one’s vaccines and good hand-washing are imperative. Although we do not know if AFM is caused by a mosquito-born illness, avoiding mosquitoes would be wise as well. More therefore needs to be researched to determine why and how those individuals with AFM were infected.