CDC Conference Call On Recent Acute Flaccid Myelitis Reports

CDC AFM Reports as of September 30, 2018

UPDATED:  Audio of CDC Presser at Audio[MP3, 4.11MB]
                      A transcript is now available HERE

#13,600

Just over a week ago, in Minnesota DOH: Statement On Cases of Acute Flaccid Myelitis, we saw the first signs of what has become the third fall uptick in AFM in this country since the fall of 2014. Cases were reported in the fall of 2016 as well, while 2015 and 2017 saw relatively few cases (see chart above).

This unusual every-other-year pattern is just one of the mysteries behind these outbreaks.

Over the past week we've seen reports from Illinois, Texas, Colorado, and several other states - but as with with the previous two outbreaks - no single overriding cause has been identified.

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 remains exceedingly rare, striking fewer than 1 person in a million each year, but of those who are affected, 90% are under the age of 18. 

AFM mayfacbe caused variety of factors, including viral infection. While many causes are never identified, we know number of viral infections can increase the risk of AFM. These can include Non-Polio Enteroviruses (NPEVs) like EV-71, EV-D68, and CV-A6, along with others, like West Nile Virus.

The CDC has been investigating these outbreaks since 2014, and while some studies have suggested EV-D68 as the likely cause of many of the cases in 2014 (see Eurosurveillance Review: Association Between Acute Flaccid Myelitis (AFM) & Enterovirus D68 (EV-D68)) no causal link for most of the cases has been established. 

The CDC outlines some of the gaps in their understanding of these outbreaks on their AFM Surveillance Webpage.

What We Don’t Know
Among the people who were diagnosed with AFM since August 2014:

• The cause of most of the AFM cases remains unknown.
• We don’t know what caused the increase in AFM cases starting in 2014.
• We have not yet determined who is at higher risk for developing AFM, or the reasons why they may be at higher risk.
• We do not yet know the long-term effects of AFM. We know that some patients diagnosed with AFM have recovered quickly, and some continue to have paralysis and require ongoing care.

Today the CDC held a press conference to provide an update on acute flaccid myelitis (AFM) in the United States, and will begin to provide weekly updates starting next Monday.

The press conference included:

Nancy Messonnier, MD (CAPT, USPHS, RET) – Director, National Center for Immunization and Respiratory Diseases, CDC

Manisha Patel, MD, MS, Acute Flaccid Myelitis Team Lead, Division of Viral Diseases, CDC

Steve Oberste, PhD, Branch Chief, Polio and Picornavirus Laboratory, Division of Viral Diseases, CDC

We should have a transcript posted later today, but for now, we are informed that the CDC has 62 confirmed cases in 2018 (up from 38 shown in the chart above), with more than 120 under investigation.

The CDC describes this fall's outbreak as similar so far to the 2014 and 2016 outbreaks, although the numbers could go higher.  While the Polio virus has been eliminated as a possibility, the etiology of these outbreaks remains elusive.

When the transcript and/or audio recordings for today's conference become available, I'll update this blog with a link.


If you suspect you or your child is suffering from unexplained muscle weakness or paralysis, it is important to seek medical care immediately. The CDC continues to investigate, but until more is known, the CDC can only offer the following advice. 

Prevention

Poliovirus and West Nile virus may sometimes lead to AFM.

• You can protect yourself and your children from poliovirus by getting vaccinated.
• You can protect against bites from mosquitoes, which can carry West Nile virus, by using mosquito repellent, staying indoors at dusk and dawn (when bites are more common), and removing standing or stagnant water near your home (where mosquitoes can breed).

While we don’t know if it is effective in preventing AFM, washing your hands often with soap and water is one of the best ways to avoid getting sick and spreading germs to other people. Learn about when and how to wash your hands.

For more information on what CDC is doing, see our AFM Investigation page.