As promised early last week, the CDC has updated their AFM Surveillance page this afternoon - and while the total number of confirmed cases remains unchanged at 62 - roughly 2 dozen new PUIs (Patients Under Investigation) have been added since last week's update (n=155).
Acute flaccid myelitis (AFM) is a rare illness that affects a person’s nervous system - specifically the spinal cord - and while rare, most cases occur in children. AFM falls under a broader `umbrella' of syndromes called Acute Flaccid paralysis (AFP).Given the delays in both reporting cases, and confirming diagnoses, it seems likely that the numbers we have today will continue to rise over the next few weeks. 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.
Although Enterovirus D68 and EV-A71 have both been implicated in past cases (along with a number of other viral suspects), as of now no definitive cause has been determined for the bulk of these cases.
Last week, in mBio: Contemporary EV-D68 Strains Have Acquired The Ability To Infect Human Neuronal Cells, we looked at a new study that adds plausibility - but not proof - that EV-D68 may be behind many of these cases.Making diagnosis more difficult, paralysis often only appears days or even weeks after a mild viral infection, and all too often no trace of the initiating virus remains detectable in the patient.
From the CDC AFM Surveillance page:
At a Glance
- CDC is concerned about AFM, a serious condition that causes weakness in the arms or legs.
- From August 2014 through September 2018, CDC has received information on a total of 386 confirmed cases of AFM across the US; most of the cases have occurred in children.
- Even with an increase in cases since 2014, AFM remains a very rare condition. Less than one in a million people in the United States get AFM each year.
- While we don’t know the cause of most of the AFM cases, it’s always important to practice disease prevention steps, such as staying up-to-date on vaccines, washing your hands, and protecting yourself from mosquito bites.
What This Graph Shows
The graph shows the number of AFM cases confirmed by CDC as of October 19, 2018, with onset of the condition through September 30, 2018.
It is currently difficult to interpret trends of the AFM data. Collecting information about suspected AFM cases is relatively new, and it is voluntary for most states to send this information to CDC. There may initially be more variability in the AFM data from year to year making it difficult to interpret or compare case counts between years.
- So far in 2018, there are 62 confirmed cases of AFM. (Note: The cases occurred in 22 states across the U.S.)
Note: These 62 confirmed cases are among the total of 155 reports that CDC received of patients under investigation (PUIs). CDC recently received increased reports for PUIs with onset of symptoms in August and September. CDC and state and local health departments are still investigating some of these PUIs. With enhanced efforts working with local and state health departments and hospitals, we were able to gather information on PUIs and confirm a number of these cases faster. CDC is now providing the number of patients still under investigation so people can better anticipate increases in confirmed cases over the coming months.
- In 2017, CDC received information for 33 confirmed cases of AFM. (Note: The cases occurred in 16 states across the U.S.)
- In 2016, 149 people were confirmed to have AFM. (Note: The cases occurred in 39 states across the U.S. and DC)
- In 2015, 22 people were confirmed to have AFM. (Note: The cases occurred in 17 states across the U.S.)
- From August to December 2014, 120 people were confirmed to have AFM. (Note: The cases occurred in 34 states across the U.S.)
- The case counts represent only those cases for which information has been sent to and confirmed by CDC.
We defer to the states to release additional information on cases as they choose.(Continue . . . )
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.
Poliovirus and West Nile virus may sometimes lead to AFM.For more information on what CDC is doing, see our AFM Investigation page.
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.
- 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).