AFM Cases in U.S.

There are 20 confirmed cases so far in 2019 (CA [7 cases], GA, MD [2 cases], NC [2 cases], NE, PA, TX [4 cases], UT, WV) out of 87 reports of PUIs.

No deaths were reported during the acute illness of patients with confirmed AFM who had limb weakness onset in 2018; however, there were two reports of patients confirmed with AFM in 2018 who had expired months after limb weakness onset. We have also learned of deaths in cases confirmed in previous years.

2018 Cases

  • There have been 235 confirmed cases of AFM in 41 states in 2018.
    • Note: These 235 confirmed cases are among the total of 384 reports that CDC received of patients under investigation (PUIs).
    • Most patients under investigation have been classified, but CDC and state and local health departments are still investigating some of the PUIs.

2018 Cases by State

2018 confirmed cases of acute flaccid myelitis (AFM) by state (N=233)*
State Case Counts
State AFM confirmed cases
Alabama 4
Arizona 5
Arkansas 3
California 15
Colorado 16
Florida 2
Georgia 4
Illinois 9
Indiana 2
Iowa 2
Kansas 1
Kentucky 4
Louisiana 2
Maryland 5
Massachusetts 5
Michigan 5
Minnesota 11
Mississippi 1
Missouri 4
Montana 3
Nebraska 5
Nevada 1
New Hampshire 1
New Jersey 11
New Mexico 1
New York State 7
New York City 3
North Carolina 2
North Dakota 1
Ohio 14
Oklahoma 4
Pennsylvania 11
Rhode Island 1
South Carolina 2
South Dakota 1
Tennessee 3
Texas 31
Utah 1
Virginia 8
Washington 11
Wisconsin 10
Wyoming 2
Total 234

We defer to the states to release additional information on cases as they choose.

Cases by Year^

There have been 587 confirmed cases since CDC began tracking AFM in August of 2014.

CDC has been thoroughly investigating the AFM cases that have occurred since 2014, when we first noted a large number of cases being reported. We have seen increases in AFM cases, mostly in young children, every two years since 2014.

States with Confirmed Cases
Year Confirmed Cases States with Confirmed Cases
2019 20 9
2018 235 41
2017 37 16
2016 153 39 (and DC)
2015 22 17
2014 (Aug-Dec) 120 34

^ The case counts represent only those cases for which information has been sent to and confirmed by CDC. Case counts are preliminary and subject to change

Cases by Month, 2014-2019

Most patients had onset of AFM between August and October, with increases in AFM cases every two years since 2014. At this same time of year, many viruses commonly circulate, including enteroviruses, and will be temporally associated with AFM.

The graph shows the number of AFM cases confirmed by CDC as of September 3, 2019, with onset of the condition through July 31, 2019.

Confirmed AFM cases reported to CDC: Aug-14 = 21, Sep-14 = 51, Oct-14 = 24, Nov-14 = 15, Dec-14 = 9, Jan-15 = 2, Feb-15 = 2, Mar-15 = 1, Apr-15 = 0, May-15 = 1, Jun-15 = 0, Jul-15 = 2, Aug-15 = 3, Sep-15 = 1, Oct-15 = 4, Nov-15 = 2, Dec-15 = 4, Jan-16 = 1, Feb-16 = 0, Mar-16 = 6, Apr-16 = 1, May-16 = 6, Jun-16 = 9, Jul-16 = 12, Aug-16 = 30, Sep-16 = 44, Oct-16 = 27, Nov-16 = 9, Dec-16 = 4, Jan-17 = 1, Feb-17 = 5, Mar-17 = 5, Apr-17 =4, May-17 =2, Jun-17 = 4, Jul-17 = 3, Aug-17 = 1, Sep-17 = 4, Oct-17 = 0, Nov-17 = 2, Dec-17 = 4, Jan-18 = 0, Feb-18 = 4, Mar-18 = 0, Apr-18 = 2, May-18 = 2, Jun-18 = 8, Jul-18 = 8, Aug-18 = 29, Sep-18 = 86, Oct-18 = 64, Nov-18 = 21, Dec-18 = 6, Jan-19 = 2, Feb-19 = 3, Mar-19 = 2

^ Confirmed AFM cases that CDC has been made aware of as of September 3, 2019 with onset of the condition through July 31, 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.

It is currently difficult to interpret trends of the AFM data. Collecting information about 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.

Page last reviewed: September 3, 2019