After a record-setting 186 cases of the polio-like disease, acute flaccid myelitis (AFM) in 2018, the peak has passed and instances of it are expected to continue to decline – until 2020.
Scientists don’t know why, but the infection, which appears to attack the spinal cord and cause temporary – and occasionally permanent – paralysis primarily in young children seems to ebb and flow in every-other-other-year waves.
The first known outbreak of unknown cause or origin occurred in 2014. AFM reemerged in 2016 and struck 149 people. Then again in 2018 the disease made a comeback, hitting a record 186 confirmed cases so far this year.
So far, it appears that AFM outbreaks occur every other year – and that each resurgence is worse than the last.
Alex Bustamante, six, is one of 186 people – almost all children – struck by acute flaccid myelitis in 2018. This has been the worst year for the disease yet and, if things continue this way, 2020 will bring more cases still
One thing is becoming increasingly clear: we can now expect an approximately 14-month lull in cases of AFM.
During that time, the Centers for Disease Control and Prevention (CDC) are determined to do their utmost to crack the mystery.
The CDC has assembled a special task force to do exactly that.
Its members include parents, neurologists, epidemiologists who study disease patterns, virologists and pathologists who are investigating potential infectious triggers for the disease, doctors who study the immune system, and those who study genetic and environmental disease risk factors.
Still, for the task force and the world at large, far more is unknown than known about AFM.
Brandon Noblitt, eight (left), got a cold earlier this year. Within a week, he was unable to walk due to AFM. Camdyn Carr, (right), was in danger of being unable to breath on his own after developing the mysterious, paralyzing disease
Alex Bustamante (pictured) was just six when he died in May after becoming paralyzed by AFM. His family says that the CDC did not recognize the polio-like illness as the cause of death
The very first cases appeared in 2012, with a series of children with an average age of 10, mostly concentrated in California.
In 2014, the disease appeared in more full force, with clusters in Colorado and Utah.
Between August and December, a total of 120 cases cropped up across 34 states.
WHAT IS ACUTE FLACCID MYELITIS (AFM)?
The term ‘myelitis’ means inflammation of the spinal cord.
Transverse myelitis is the broad name of the disease, and there are various sub-types.
It is a neurological disorder which inflames the spinal cord across its width (‘transverse’), destroying the fatty substance that protects nerve cells.
That can lead to paralysis.
AFM is an unusual sub-type of transverse myelitis.
Patients starts with the same spinal inflammation, but their symptoms are different and the disease develops differently.
The main distinction is that AFM patients are weak and limp, while patients with general transverse myelitis tend to be rigid.
Most AFM patients start to struggle with movement of the limbs, face, tongue, and eyes.
They then begin to lose control of one limb or sometimes the whole body – though many maintain control of their sensory, bowel and bladder functions.
Unlike transverse myelitis, which has been around for years, doctors are still in the dark about why and how AFM manifests itself.
And then, just as quickly as it had come, AFM dissipated again.
In both those first sporadic 2012 cases and the 2014 ones, doctors were able to establish one commonality.
Those outbreaks coincided with another, of a viral respiratory infection caused by a bug dubbed EV-D68.
But the discovery was a bit of a dead end.
Although about 90 percent of people with AFM had recently had a cold affecting their respiratory systems, traces of EV-D68 and other enteroviruses were found in the spinal fluid of only four out of 512 people confirmed to have the polio-like disease since 2014.
This has left the majority of cases unexplained.
The vast majority of those struck by the disease are young children, and it presents at first not unlike polio.
Most loose strength and muscle control of one limb first, and the paralysis spreads from there.
In rare cases, the freezing can spread to the respiratory system, rendering the disease life-threatening.
To many older, terrified parents AFM at first looked like polio, which has been effectively eradicated by vaccination.
However, no on with AFM has thus far texted positive for the devastating disease.
It seems clear that whatever underlies AFM must attack the spinal cord, seeing as how paralysis is the primary symptom.
Yet tests on the spinal fluid of AFM children were often negative for any suspicious viruses.
As they look ahead to 2020, scientists are hoping to piece together what distinguishing genetic and environmental factors make some children susceptible while others are safe.
Sebastian Bottomley was just five when AFM struck him in 2016. The now-seven-year-old (pictured) has relied on a wheelchair to get around ever since
They are also investigating how a pathogen might infect different types of cells than they had previously examined, such as muscle cells themselves, or if an infection could trigger inflammation and an autoimmune response.
Furthermore, they intend to ‘implement natural history stud[ies]’ to try to understand what sort of biannual ‘seasons’ or cycles may fuel the disease’s pattern.
Nonetheless, there is little that scientists can do to predict the future, especially in the case of AFM.
‘It is impossible to say if we’ll have any real answers … because this is a complex public health challenge,’ the CDC’s Dr Thomas Clark, an epidemiologist told the Dallas Morning News.
And that leaves parents in the terrifying position of simply hoping for the best for their vulnerable children.
‘Until we fully understand what causes AFM, we can’t help protect people against it.’
Currently, epidemiologists like him have little to go on except the patterns that we have observed since 2014.
And if these are any indication, we can only expect more, sicker children in the winter or 2020.