#15,400
With many schools planning to reopen this month, the primary concern is naturally over COVID-19; How risky will it be for kid's health - and even if we get lucky, and kids are only mildly affected - how will it affect the transmission of the virus in the larger community?
But the return to school each fall is also associated with an uptick in other infectious (mostly mild respiratory) diseases - and while enhanced COVID precautions should dampen those illnesses as well - in rare cases some of these illnesses can be life-threatening.
At the same time, doctors around the country reported a concurrent spike in polio-like paralysis in children (e.g. AFP or AFM (Acute Flaccid Myelitis)) often following a viral illness.While the exact causes of Acute flaccid myelitis aren't fully understood, it has been linked to a number of viral infections, including West Nile Virus, Adenoviruses, and a number of (polio and non-polio) enteroviruses, including EV-71 and more recently, EV-D68.
Every two years since then (fall of 2016 and 2018) we've seen an increase in AFM cases (see above graphic), with the largest wave (n=233) reported in 2018. While the impact of the COVID-19 pandemic on AFM is unknowable, this rare neurological disease is expected to return again this fall.
Even though 2019 was an `off year' for AFM. we revisited the topic several times, looking at the latest research, including:
EID Journal: Association of EV-D68 with Acute Flaccid Myelitis, Philadelphia, PA, USA, 2009–2018
CDC Vital Signs: Acute Flaccid Myelitis (AFM)
mBio: Acute Flaccid Myelitis (AFM) - Something Old and Something New
While tens of thousands of children may contract EV-D68, most will come away with little more than a summer `cold'. Only a few hundred will go on to develop AFM. But for those few, it can be life threatening illness, and many who do survive can end up with lasting paralysis or limb weakness.
Early recognition is key, both for learning more about the causes of AFM, and for expediting emergency treatment.
Because the calendar suggests another wave of EV-D68 is likely to occur this fall, and concerns that our concurrent COVID-19 pandemic could delay diagnosis and treatment of AFM, this week the CDC has launched a new Vital Signs report on AFM, along with publishing a new MMWR report, and holding a press briefing.
First stop, the audio recording and transcript of a press briefing held on Tuesday, Aug 4th.
CDC Expects 2020 Outbreak of Life-Threatening Acute Flaccid Myelitis TranscriptPress Briefing TranscriptPlease Note: This transcript is not edited and may contain errors.
Next stop, a link and some excerpts from this month's Vital Signs Report.
Acute Flaccid Myelitis (AFM)
Recognize symptoms. Hospitalize immediately.
Overview
Acute flaccid myelitis (AFM) is an uncommon, but life-threatening neurologic condition that affects mostly children and can lead to permanent paralysis. Enteroviruses, particularly EV-D68, are likely responsible for the increase in cases every two years since 2014. AFM is a medical emergency and patients must be hospitalized and monitored in case they progress to respiratory failure. Prompt recognition and immediate action by pediatricians, and emergency department and urgent care providers are critical to achieving the best possible outcomes.
- AFM typically presents with sudden limb weakness. Most patients had respiratory illness or fever before AFM onset.
- Patient health can decline quickly, resulting in paralysis or the need for a ventilator.
- AFM can lead to permanent disability.Patients who tested positive for EV-D68 typically had more severe AFM illness, requiring hospitalized intensive care and ventilation.
- Most cases occur between August and November.
And lastly, a link and summary from this week's MMWR Early Release on clinical characteristics of patients with confirmed AFM.
Early Release / August 4, 2020 / 69Sarah Kidd, MD1; Adriana Lopez, MHS1; W. Allan Nix1; Gloria Anyalechi, MD2; Megumi Itoh, MD3; Eileen Yee, MD1; M. Steven Oberste, PhD1; Janell Routh, MD1 (View author affiliations)View suggested citationSummaryWhat is already known about this topic?Since U.S. surveillance for acute flaccid myelitis (AFM) began in 2014, reported cases have peaked biennially. Most cases occur in children during late summer and early fall.What is added by this report?Among 238 patients with confirmed AFM during 2018, most (92%) had prodromal fever, respiratory illness, or both. In addition to weakness, common symptoms were gait difficulty (52%), neck or back pain (47%), fever (35%), and limb pain (34%). Among 211 who were outpatients when weakness began, 64% sought treatment at an emergency department. Overall, 23% required endotracheal intubation and mechanical ventilation.What are the implications for public health practice?Clinicians should suspect AFM in children with acute flaccid limb weakness, especially when accompanied by neck or back pain and a recent history of febrile respiratory illness. Increasing awareness in frontline settings such as emergency departments should aid rapid recognition and hospitalization for AFM.
While EV-D68 was discovered nearly 60 years ago in California, until 2014 it was considered both rare, and a fairly innocuous cause of mild summer `cold-like' illnesses, primarily in children.
In the past decade EV-D68 appears to have evolved into a more pathogenic (and neurotropic) virus (see mBio: Contemporary EV-D68 Strains Have Acquired The Ability To Infect Human Neuronal Cells).
Similarlly, last year Priyanka Uprety et al. from the Children’s Hospital of Philadelphia and the University of Pennsylvania, Philadelphia wrote in an EID Journal Article:
These data suggest that the EV-D68 genome has changed over time to enable neurotropism or possibly increased virulence resulting in more widespread disease.Some researchers are even asking if EV-D68 has the potential to become the next `polio' (see Enterovirus D68 – The New Polio?). Similar questions have been asked over EV-71, which has caused numerous large scale outbreaks (with AFM) - mostly in Asia - over the past 20 years.
This isn't the first (nor will it be the last) time that we've seen a previously obscure, and relatively benign, infectious disease evolve into a deadlier threat.
While full blown pandemics - like COVID-19 and pandemic influenza - have been infrequent events, we can expect to be continually challenged by less dramatic, but nevertheless serious public health threats going forward.
EV-D68 is just one of many that have either emerged or re-emerged over the past 20 years or so. Others include:
- Nipah & Hendra
- SARS
- MERS-CoV
- H5Nx & H7Nx avian Influenza
- Ebola
- EV-71
- West Nile Virus
- Monkeypox
- Hantavirus
- Chikungunya
- Dengue
- Zika
COVID-19 has shown that it doesn't require a zombie apocalypse or a 30% CFR avian flu pandemic to crash our economy and turn our world upside down. Our stunning lack of preparedness going into this pandemic has only made matters worse.
Nature's laboratory keeps firing warning shots across our bow, and for the most part, we've ignored them. One has to wonder how much damage we have to take before we begin to treat emerging infectious diseases like the national security threats they really are.
