AFM Confirmed U.S. Cases
^ Confirmed AFM cases that CDC has been made aware of as of March 29, 2019 with onset of the condition through February 28, 2019. The case counts are subject to change.
* The data shown from August 2014 to July 2015 are based on the AFM investigation case definition: onset of acute limb weakness on or after August 1, 2014, and a magnetic resonance image (MRI) showing a spinal cord lesion largely restricted to gray matter in a patient age ≤21 years.
† The data shown from August 2015 to present are based on the AFM case definition adopted by the Council of State and Territorial Epidemiologists (CSTE): acute onset of focal limb weakness and an MRI showing spinal cord lesion largely restricted to gray matter and spanning one or more spinal segments, regardless of age.
For more information, visit the Case Definitions page.
The graph shows the number of AFM cases confirmed by CDC as of March 29, 2019, with onset of the condition through February 28, 2019.
- So far in 2019, there have been four confirmed cases (from NE, NC, UT, and WV) out of 25 reports of PUIs.
- In 2018, there are 228 confirmed cases of AFM. (Note: The cases occurred in 41 states across the U.S.)
Note: These 228 confirmed cases are among the total of 378 reports that CDC received of patients under investigation (PUIs). Most of the 2018 PUIs have been classified, but CDC and state and local health departments are still investigating some of these PUIs.
- In 2017, CDC received information for 35 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 peopleExternal 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.
It is currently difficult to interpret trends of the AFM data. Collecting information about patients under investigation (PUIs) for AFM is relatively new. 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.
We defer to the states to release additional information on cases as they choose.