More Reports Of Acute Flaccid Myelitis Around The Country

Credit CDC

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On Monday, in Minnesota DOH: Statement On Cases of Acute Flaccid Myelitis, we looked at an investigation into 6 cases of AFM in Minnesota of unknown origin.  Overnight, we're learning of 14 more cases in Colorado, 3 cases in Pennsylvania, and at least 1 case in Chicago.  

Acute flaccid myelitis (AFM) is a rare illness that affects a person’s nervous system, specifically the spinal cord. AFM falls under a broader `umbrella' of syndromes called Acute Flaccid paralysis (AFP). AFM may be due to a variety of causes, including viral infection.

While the cause often goes undetermined, a number of viral infections can  increase the risk of AFM. They include Non-Polio Enteroviruses (NPEVs) like EV-71, EV-D68, and CV-A6, along with West Nile Virus, Epstein-Barr virus, and a handful of adenoviruses. 

Symptomatic NPEV infections (many are asymptomatic) usually range from just a mild fever or a runny nose - to Hand Foot Mouth Disease (HFMD), a generally  mild childhood disease characterized by blisters on the hand, feet, and mouth.

Very rarely, they can produce a polio-like paralysis and sometimes even death.

In 2014 a nationwide outbreak of a rarely seen EV-D68 was linked to a concurrent spike in AFP (Acute Flaccid Paralysis) cases across the United States, and since then we've seen a number of EV-D68 outbreaks around the world (see here, here & here).

While a causal link between EV-D68 and AFM hasn't been fully established, last January's Eurosurveillance Review: Association Between Acute Flaccid Myelitis (AFM) & Enterovirus D68 (EV-D68), presented a pretty good argument for causation. 

The number of AFM cases remains small - 362 cases of AFM across the US since 2014 -  but their impact on the lives of the patients and their families can be enormous.  And - for the first time since 2016, we appear to be seeing an uptick.

For the past two decades - particularly in Asian and Western Pacific nations - we've monitored yearly NPEV epidemics of a much more serious nature, with the most severe illness linked to Human Enterovirus 71 (EV-71), which can cause a polio-like paralysis, and sometimes even death.

While EV-71 has been reported in both Europe and the United States, we've not seen anything like the outbreaks that have plagued China, Taiwan, and Southeast Asia the past 20 years.  

We've the following statement from the Colorado Department of Public Health & Environment on a recent spike in AFM, many associated with EV-71.  

Statement from CDPHE on enterovirus and acute flaccid myelitis

Shannon Barbare, Communications Specialist | 303-692-2036 | shannon.barbare@state.co.us
FOR IMMEDIATE RELEASE: Oct. 9, 2018

DENVER - The Colorado Department of Public Health and Environment continues to work with the U.S. Centers for Disease Control and Prevention to investigate an outbreak of viral infections with neurologic complications among young children. Testing by the CDC shows most of these cases are associated with enterovirus A71.

This year, Colorado has had 41 cases of enterovirus A71 infections associated with neurologic illness in children. As part of this outbreak, Colorado also has had 14 cases of acute flaccid myelitis (AFM). Of the AFM cases, 11 tested positive for enterovirus A71, one tested positive for enterovirus D68, and two tested negative for enteroviruses.
While all the patients were hospitalized, nearly all have fully recovered. There have been no deaths.

Acute flaccid myelitis is a condition that affects the spinal cord; most patients who get it have a sudden onset of limb weakness, and most recover from the illness.

Enteroviruses are common and can cause cold-like illnesses; hand, foot and mouth disease; and skin rashes. EV-A71 and EV-D68 are less-common types of enterovirus in the United States, and usually cause mild illness. Rarely, they may cause neurologic illnesses not commonly seen with other enteroviruses, such as meningitis, encephalitis and acute flaccid myelitis.

All enteroviruses are spread through contact with an infected person’s feces; eye, nose and mouth secretions (such as saliva, nasal mucus or sputum); and fluid from blisters caused by the virus. Some people with enteroviruses have no symptoms but still can spread the virus to others. Typically, enterovirus cases increase in the summer and fall.

There is no vaccination or specific treatment for enteroviruses. People with mild illness typically need treatment only for symptoms. However, some illnesses caused by EV-A71 and EV-D68 can be severe enough to require hospitalization.

The state health department has been monitoring this situation closely since early spring. In addition to investigating the outbreak, the department has issued alerts to health care providers on how to test for the viruses and enhanced guidance to child care centers on infection prevention.

Symptoms of enterovirus complications or acute flaccid myelitis

Parents and guardians should contact a health care provider if they or their children have:

• Severe symptoms such as sudden weakness in arms and legs, trouble breathing, unsteady walking, severe headache, stiff neck or seizures.
• Dizziness, wobbliness, or abnormal, jerking movements that are worse at night.
• Fever along with any other concerning symptoms.

To protect yourself and others from enteroviruses

• Wash your hands often with soap and water for at least 20 seconds.
• Be especially careful to wash your hands after using the toilet and changing diapers.
• Avoid close contact with people who are sick, and don’t share cups and eating utensils.
• Clean and disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.
• Cover your coughs and sneezes.
• Avoid touching your eyes, nose and mouth with unwashed hands.
• Stay home when you’re sick, and keep children home from school or daycare for 24 hours after fever ends or if they are drooling uncontrollably and have mouth sores.

Colorado has experienced previous outbreaks of less-common enteroviruses. In 2014, enterovirus D68 caused an outbreak of respiratory illness in Colorado children and was associated with 11 cases of acute flaccid myelitis. In 2003 and 2005, enterovirus A71 caused outbreaks similar to what Colorado is experiencing now, with eight cases of central nervous system infections occurring in each of those years.

Overnight, from Pennsylvania, we have a media report of 3 cases of AFM from Allegheny County (see UPMC confirms 3 suspected cases of rare disease that paralyzes children).

And from Chicago, we have a report of a Batavia toddler treated for rare polio-like illness in Chicago.

Investigations into the causes of these illnesses are ongoing, and they many not be the same as the Colorado cases. 

Last month, in EID Journal: Emerging Enteroviruses In China 2010-2016, we looked at the spread, impact, and evolution of enterovirus A71 (EV-A71), coxsackievirus (CV) A16, and the recently rising Coxsackievirus A6. 

The authors cautioned:

Given the numerous CVA6 outbreaks in multiple countries in 2008 and a US population that may be relatively naïve to this serotype, CVA6 is likely to spread throughout North America.

Just as with influenza, these non-polio enteroviruses continue to evolve - and while not as deadly as flu - they are fully capable of causing large epidemics.  So we monitor their progress closely.

 
Some of my previous NPEV blogs include:

MMWR: Cluster of Acute Flaccid Myelitis in Five Pediatric Patients - Arizona, 2016

CDC Acute Flaccid Myelitis Update - January 2017

EID Journal Upsurge In EV-D68 In The Netherlands, 2016

ECDC: Rapid Risk Assessment On Recent Enterovirus Outbreaks In Europe

EID Journal: New Introductions Of EV-71 Subtype C4 To France – 2012