Frequently Asked Questions by Clinicians and Health Departments

Reporting Cases

How can I send information about a case of AFM?

If you believe your patient has symptoms of AFM, contact your state or local health department as soon as possible for instructions on how to report. You can direct urgent questions to the CDC Emergency Operations Center (770-488-7100). Email non-urgent questions to the AFM team at

In addition, please collect cerebrospinal fluid (CSF), respiratory, serum, and stool specimens for testing as soon as possible to increase the possibility of finding a cause. These specimens can be tested at a hospital or state public health laboratory for enteroviruses, West Nile virus, and other infectious etiologies known to be associated with AFM. At the same time, you should send additional aliquots of CSF, respiratory, serum, and stool samples to CDC for testing for both infectious and non-infectious causes. Sending whole stool specimens is particularly important to help rule out polio. See Specimen Collection Instructions for more information, including shipping and handling.

Health Departments
If you have received information about a patient under investigation (PUI) for AFM:
  • Complete the patient summary form in conjunction with the clinician.
  • Collect the requested clinical information (i.e., MRI report, MRI images, neurology consult notes, if done and available).
  • Contact CDC (, to coordinate the case classification process.

Should I send information about a patient under investigation (PUI) for AFM even if his/her clinical specimen was negative for enteroviruses?

Yes, we request that you send biologic specimens and information about all patients under investigation (PUIs) to the health department, regardless of laboratory testing results. CDC tests specimens to identify the pathogens and biologic mechanisms responsible for AFM. These tests include, but are not limited to, tests for enteroviruses.

Do states have requirements for reporting AFM?

All jurisdictions have requirements for clinicians to report patients under investigation (PUIs) for AFM. Some require AFM to be reportable, some require clinicians to report suspicion of acute onset of flaccid paralysis without other apparent cause, and some require reporting of new or emerging conditions of public health importance, like AFM. State and local health departments, the Council of State and Territorial Epidemiologists (CSTE), and CDC, will continue to collaborate and respond to this complicated and deeply concerning illness.

For more information, see CSTE statement about AFM.

Specimen Collection & Testing


Because specimen submission requirements for CLIA diagnostic testing are currently being updated, ALL submissions to CDC for diagnostic testing require pre-approval at this time. Please contact before submitting AFM specimens to CDC.

Should I send specimens to CDC even if the hospital laboratory or state public health laboratory can test for enteroviruses?

Yes, we request that you send specimens (i.e., CSF, respiratory, serum, and stool samples) to CDC for standardized testing and for our expanded testing protocols. Contact your health department to coordinate sending of specimens to CDC for testing. Upon completion, we will share with the health department the results from certain tests, such as enterovirus/rhinovirus testing and typing and stool testing. The health department will then share the results with the clinician. For instructions on how to submit specimens to CDC, see Specimen Collection Instructions.

What happens to the patient specimens that I send to CDC, and when should I expect to receive the testing results?

All specimens submitted to CDC help us learn more about AFM, including possible causes and how the immune system responds to this condition. You should not use results from these tests to inform clinical management of your patient because results may not be available in real-time.

  • Respiratory and stool specimens: As soon as they are completed, we will share with the specimen submitter and the health department the respiratory testing and typing results for enterovirus/rhinovirus and stool testing for poliovirus. The health department will then share the results with the clinician.
  • Other specimens: We will use results from other specimens (e.g., CSF and serum) for exploratory testing to learn more about immune responses to AFM. Results will not be immediately available.

Since CDC testing protocols include several immunoassays that are not approved by the Clinical Laboratory Improvement Amendments (CLIA) nor are intended for clinical diagnosis, CDC will be unable to provide patient-specific results for certain tests that are performed. However, we will rapidly disseminate results from exploratory testing of samples from multiple cases which may indicate a possible cause of AFM.

Infection Control

What are your interim infection control recommendations for healthcare professionals?

Our interim recommendation for management of patients with acute flaccid myelitis is Standard + Contact + Droplet precautions. This is consistent with CDC’s recommendations for EV-D68. There are no pathogen-specific recommendations to add at this time.

Case Classification

When should I expect AFM case classification results back from CDC?

The case classification will be communicated through the state or local health department when the review is complete, generally about 4 weeks after all of the information is received.

The process for case classification requires collection of many different pieces of information, including neurology notes and MRI images, which are then reviewed by several experts. Case classification is used for surveillance purposes and should not interfere with the differential or final clinical diagnosis or treatment of the patient. Visit AFM Case Definitions for more information.

Patient Follow-up

Will CDC conduct extended follow-up on cases of AFM after their initial clinical presentation?

Currently, we are working with health departments to collect long-term follow-up information (2 months, 6 months, and 12 months after onset of limb weakness) about confirmed and probable cases of AFM.

We conducted a short-term follow-up survey on cases with information collected during the 2014 investigation and received responses from roughly half (56) of the identified cases.

  • A small number described complete recovery of limb function after a median of about 4 months after onset of limb weakness.
  • The majority described some improvement of function.
  • A small number described no improvement in limb function.

Learn more about the long-term follow-up conducted on AFM cases from Colorado that occurred in 2014.


Do intramuscular injections play a role in AFM?

Among many ongoing investigation activities to determine the cause of AFM, CDC is looking at any possible association between intramuscular injections given in healthcare settings, such as medications and vaccines, and AFM. CDC collects medical information on all suspected cases of AFM in the United States that are reported to us from health departments. A history of intramuscular injections received in the 30 days prior to limb weakness is recorded for all cases. Of the AFM cases reviewed thus far, approximately 85% have no recorded vaccination in the 30 days prior to the onset of limb weakness.

Are there any vaccines or medications to protect against AFM?

At this time, there are no vaccines or medicines, such as antivirals, that have been proven to protect a person from getting AFM or treat a person who has AFM. Visit CDC’s AFM Clinical Management of Patients webpage for a summary of acute medical treatments.

Although there is no vaccine for AFM, being up to date on all recommended vaccinations is essential to prevent a number of severe diseases including polio, which can cause acute flaccid paralysis, and numerous other vaccine-preventable diseases.