Specimen Collection Instructions

CDC continues to search for potential causes of acute flaccid myelitis (AFM) by broadening laboratory approaches that test for potential infectious, including immune-mediated mechanisms and host responses to AFM.

Specimen testing protocols

  • To support the updated testing protocols, CDC will prioritize testing of cerebrospinal fluid (CSF) and serum to optimize yield of an etiologic agent or possible mechanism for AFM.
  • CDC will conduct routine testing and typing of CSF, respiratory specimens and stool for enterovirus/rhinovirus, and poliovirus testing of stool specimens to rule out the presence of poliovirus.
  • Additional testing protocols are being developed to look for AFM biomarkers and studies to identify possible mechanisms for AFM are underway.
  • Pathogen-specific testing should continue at hospital or state public health laboratories and may include CSF, sera or whole blood, stool, and respiratory specimens.

Early specimen collection is critical

Clinicians should collect specimens from patients under investigation (PUIs) for AFM as early as possible in the course of illness, preferably on the day of onset of limb weakness. Early specimen collection has the best chance to yield a cause of AFM.

specimen collection tools

Clinicians should:

If specimens have not been collected or all of the available specimens have been used and no specimen remains, you should repeat specimen collection, when feasible.

Sharing testing results

  • Since the testing protocols include several assays that are not performed under the Clinical Laboratory Improvement Amendments (CLIA) nor intended for clinical diagnosis, CDC will be unable to provide patient-specific results for certain tests that are performed.
  • Results following testing of samples from multiple cases that may indicate a possible cause of AFM will be rapidly disseminated.
  • Results from certain tests, such as EV/RV testing and typing and stool testing, will be shared with the health department upon completion.

CDC appreciates your assistance and participation in this important endeavor. With your assistance, we hope to gain further insights into the nature of this unusual condition.

Specimens to collect and send to CDC for testing for Patients Under Investigation (PUIs) for AFM

Cerebrospinal fluid (CSF)
specimen collection tool - CSF

Spun and processed; collect at same time or within 24 hours of serum if feasible

Cerebrospinal fluid (CSF)
Minimum Amount 1 mL
Tube Type Cryovial
Storage Freeze at -70°C
Shipping Ship on dry ice
Results of Testing CSF will be used for special studies; EV/RV testing will be batched and results returned as sample amount allows
Serum*
specimen collection tool - Serum

Spun and processed; collect at same time or within 24 hours of CSF if feasible

Serum
Minimum Amount 0.4 mL
Tube Type Tiger/red top
Storage Freeze at -70°C
Shipping Ship on dry ice
Results of Testing Serum will be used for special studies; no individual results will be returned
Whole stool
specimen collection tool - stool

Two samples total, collected at least 24 hours apart, both collected as early in illness as possible and ideally within 14 days of illness onset

Whole stool
Minimum Amount ≥1 gram
Tube Type Sterile container; Not a rectal swab†.
Storage Freeze at -20°C**
Shipping Ship on dry ice
Results of Testing Results for EV/RV and poliovirus testing will be returned as testing completed (within 14 days)
Respiratory - nasopharyngeal (NP) or oropharyngeal (OP) swab
specimen collection tool - NP Swab

Store in viral transport medium

Respiratory – nasopharyngeal (NP) or oropharyngeal (OP) swab
Minimum Amount 1 mL
Tube Type N/A
Storage Freeze at -20°C**
Shipping Ship on dry ice
Results of Testing EV/RV testing and typing will be performed and results returned within 10 days of sample receipt

*If any of the serum samples that you are sending to CDC were collected after the patient had received intravenous immune globulin (IVIG), steroid treatments, or plasmapheresis/plasma exchange, please indicate the date of that therapy on the Patient Summary Form.

† The negative predictive value is very low for rectal swabs since the amount of fecal material collected is much less than for stool.

**All specimens may be stored at -70⁰C for ease of shipping.

Specimens to collect and send to CDC for testing in the event of death

In the event of death, please send the following specimens, if possible.

Fresh-frozen tissue
Fresh-frozen tissue
Collection & Storage
  • Place directly on dry ice or liquid nitrogen
  • Freeze at -70°C
Shipping Ship on dry ice
Formalin-fixed or formalin-fixed, paraffin-embedded tissue
Formalin-fixed or formalin-fixed, paraffin-embedded tissue
Collection & Storage
  • Avoid prolonged fixation—tissues should have been fixed in formalin for 3 days, then transferred to 100% ethanol
  • Room temperature

 

Shipping Ship at room temperature with paraffin blocks in carriers to prevent breakage

Handling and shipping

State and local health departments and clinicians treating PUIs may contact CDC for further laboratory and epidemiologic support by phone through the CDC Emergency Operations Center (770-488-7100), or by email at AFMinfo@cdc.gov (epidemiology information) or by email at AFMLab@cdc.gov (laboratory information).

  • Overnight shipping:  CDC advises overnight shipment of available clinical specimens from patients under investigation (PUIs) for AFM to CDC to optimize yield from specialized testing.
  • Arrive Tuesday through Friday:  Please ship specimens overnight so they arrive at CDC on Tuesday through Friday. Do not ship specimens on Friday or over the weekend.
  • For samples that should be frozen:  Please freeze them at -20°C (for fresh-frozen tissues, use -70°C) and make arrangements to ship the samples overnight to CDC frozen on dry ice.
  • Include Patient Forms:  Samples from each patient should be shipped with completed hard copies of
  • If 10 or more patient specimens are submitted:  Please provide an electronic line listing by email. Use the following headers in this order: patient ID number; date of birth; sex; onset date; fatal y/n; specimen ID number; specimen collected date; specimen type; if culture isolate—cell line and passage number.

Prior to shipping, send an email

Prior to shipping, send an email regarding what is being shipped and include the name, phone number and email address of the shipper.

Please send this information to the following mailboxes:

Shipping address

William Allan Nix
Centers for Disease Control and Prevention
RDSB/STAT
ATTN: Polio and Picornavirus Laboratory Branch; Unit 76
1600 Clifton Road, NE
Atlanta, GA 30329-4027
Office: +1-404-639-1689       Mobile: +1-404-398-8310
Email: AFMLab@cdc.gov

Contact us with questions

State and local health departments and clinicians treating PUIs may contact CDC for further laboratory and epidemiologic support by:

  • Phone: CDC Emergency Operations Center (770-488-7100)
  • Email: AFMinfo@cdc.gov (epidemiologic support)
  • Email: AFMLab@cdc.gov (laboratory support)
Page last reviewed: January 31, 2020