Diagnosing and Classifying AFM

Many individuals and groups play important roles in diagnosing AFM, caring for patients, and studying why some children get it while others do not. You can help us make progress by sharing information about your child’s illness to help us better understand AFM.

Clinicians Diagnose AFM. CDC Classifies AFM.

CDC has case definitions for AFM with specific criteria that we use to classify patients as having a confirmed or probable case of this illness. If a patient does not meet these criteria, they are classified as “not a case” of AFM. Our AFM case definitions provide a set of consistent criteria to help us define and learn more about this uncommon condition, and they are the basis for our AFM surveillance. Even though some patients may not meet our case definitions, the information provided about these patients still helps us understand the full spectrum of illness.

A case classification by CDC is not meant to override a clinician’s diagnosis of a patient’s illness, or their treatment and rehabilitation plan. If AFM is suspected, the clinician should hospitalize the patient, refer them to specialists, monitor them for signs of worsening symptoms, and begin treatment and rehabilitation.

AFM diagnosis is …

  • Done by examining the nervous system in combination with reviewing the MRI (pictures of the spinal cord)
  • Meant to get the patient into medical treatment and care
  • Done by a doctor
  • Independent from CDC’s case classification

AFM surveillance is …

  • Done through reviewing patient medical records and classifying cases
  • Meant to help detect outbreaks and inform investigation and research into possible risk factors, treatments, outcomes, and ways to prevent it
  • Done by CDC
  • Independent from doctor’s diagnosis
Infographic: Clinicians help children with AFM get the best care. CDC works with clinicians to better understand AFM.

Clinicians help children with AFM get the best care. CDC works with clinicians to better understand AFM. Illustration of house and family. Illustration of child. Patient develops symptoms.

Diagnosis and Treatment
Illustration of patient in bed. Hospitalizes patient.
Illustration of vial, MRI machine, and doctor standing over patient in bed. Specimens collected. Neurological exam and MRI performed. Medical management, including rehabilitation.

Illustration of doctor. Clinician suspects AFM

Doctors should immediately begin treatment and not wait for CDC to determine if it is a case of AFM.

Surveillance and Research
Illustration of building. Reports to health department.
Illustration of vial and documents over a CDC building. Medical records and specimens sent to CDC.
CDC determines if it is a case. CDC sends determination to Health Department, Doctor, and Patient.

Case information is used for further investigation and research. Case determination is not a diagnosis and should remain separate from patient care and treatment.

Page last reviewed: January 13, 2020