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| CDC AFM Website |
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Acute flaccid myelitis (AFM) is a rare illness that affects a person’s nervous system, specifically the spinal cord. AFM is a subset of conditions that fall under a broader `umbrella' of syndromes called Acute Flaccid paralysis (AFP), which may include myelitis, peripheral neuropathy, myopathy, Guillain-BarrĂ© syndrome (GBS), toxic neuropathy, and other muscle disorders.
While the exact causes of AFM aren't fully understood, it has been linked to a number of viral infections, including West Nile Virus, Adenoviruses, and - quite often - to number of (polio and non-polio) enteroviruses, including EV-71 and more recently, EV-D68.While AFP has been described for hundreds of years, starting about a decade ago we began seeing unprecedented outbreaks of AFM - mostly in children - increasingly associated with recent infection with NPEVs (non-polio enteroviruses).
In 2011, in MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010, we looked at a half dozen EV 68 associated clusters which occurred in Asia, Europe, and the United States during 2008--2010.
In August of 2014, EV-D68 abruptly appeared in America’s heartland and quickly spread across the nation, causing a wide spectrum of respiratory illness, predominantly in young children and adolescents (see Kansas City Outbreak Identified As HEV 68).
Coincident with this outbreak doctors reported a rise in cases of neurological illness presenting with AFP (acute flaccid paralysis) or limb weakness – often associated with a recent respiratory illness – mostly in children.A second, similar outbreak was reported in the fall of 2016, but no concurrent outbreak of EV-D68 was noted. This was followed by an even larger third outbreak in 2018 (see CDC chart below), which appears to be at least partially linked to both EV-D68 and EV-71.
In the open access journal mBio today, three well known NIH scientists and occasional collaborators - David M. Morens, Jeffery K. Taubenberger, and Anthony S. Fauci - have put together a terrific overview and perspective on the recent emergence of AFM as a recurring epidemic disease and its (sometimes tenuous) links to NPEVs.
A few of their past works well worth revisiting include:
EID Journal: Morens & Taubenberger On The Evolution Of HPAI H5Nx
Morens & Taubenberger - Influenza Viruses: Breaking All the Rules
mBio: An H7N9 Perspective by Morens, Fauci & Taubenberger
Morens and Taubenberger: A New Look At The Panzootic Of 1872
Rather than doing an injustice by trying to cherry pick excerpts, I've only included a few opening paragraphs, so I highly recommend you follow the link to read it in its entirety. I'll have a short postscript when you return.
Perspective | Clinical Science and Epidemiology
Acute Flaccid Myelitis: Something Old and Something New
David M. Morens, Gregory K. Folkers, Anthony S. Fauci
Arturo Casadevall, Editor
DOI: 10.1128/mBio.00521-19
ABSTRACT
Since 2014, acute flaccid myelitis (AFM), a long-recognized condition associated with polioviruses, nonpolio enteroviruses, and various other viral and nonviral causes, has been reemerging globally in epidemic form. This unanticipated reemergence is ironic, given that polioviruses, once the major causes of AFM, are now at the very threshold of global eradication and cannot therefore explain any aspect of AFM reemergence.
Instead, the new AFM epidemic has been temporally associated with reemergences of nonpolio enteroviruses such as EV-D68, until recently thought to be an obscure virus of extremely low endemicity. This perspective reviews the enigmatic epidemiologic, virologic, and diagnostic aspects of epidemic AFM reemergence; examines current options for clinical management; discusses future research needs; and suggests that the AFM epidemic offers important clues to mechanisms of viral disease emergence.
PERSPECTIVE
In recent decades, new human infectious diseases such as HIV/AIDS, severe acute respiratory syndrome (SARS), and Nipah virus infection, among others have emerged. Well-known diseases also have reemerged because of human movement, crowding, and other population factors (e.g., dengue and dengue hemorrhagic fever), warfare and natural disasters (e.g., cholera), and viral evolution (e.g., poultry-adapted influenza A H5N1 and H7N9) (1).
Joining this list is epidemic acute flaccid myelitis (AFM), characterized by sudden denervation-associated muscle paralysis of healthy children (and occasionally adults) in one or more limbs that mimics poliomyelitis but which is not caused by polioviruses (2). AFM was first recognized around 2010 as a seemingly novel condition (3, 4) and quickly grew into an alarming and important disease threat, with the first large outbreak occurring in 2014 (5).
Since then, seasonal waves have occurred every other year in the United States, the largest occurring in 2018 (Fig. 1) (6–8)). Because of its uncertain cause and pathogenesis, enigmatic epidemiology, and limited treatment options, the disease captured national attention and triggered considerable concern among parents of young children.(Continue . . . . )
Some additional blogs on AFM and NPEVs you may wish to revisit include:
Acute Flaccid Myelitis In Canada - CMAJ Review
CDC Update & Statement On Acute Flaccid Myelitis (AFM)
mBio: Contemporary EV-D68 Strains Have Acquired The Ability To Infect Human Neuronal Cells
More AFM Reports & Recent Studies On AFM
