Laboratory Testing Guidance

Types of Samples needed:

• Blood specimen collected in purple top EDTA tube (whole blood, plasma) or serum; whole blood is preferred to plasma or serum
  • Nucleic acid amplification testing (NAAT, e.g. PCR) is preferred for adenovirus detection. Testing whole blood by PCR may be more sensitive than testing plasma or serum by PCR and is preferred.
  • DO NOT freeze the whole blood for diagnostic PCR testing.
  • Specimens should be packaged in compliance with IATA regulations for submission of diagnostic samples.

• SPHL ONLY: If a whole blood adenovirus PCR test is not available at your laboratory, please submit to a reference laboratory.
  • Quest Diagnostics: 0.35 mL minimum volume, specimen stability (48 hours room temperature; 7 days refrigerated); Adenovirus DNA, Quantitative Real-Time PCR | Test Detail | Quest Diagnostics

• • ARUP Laboratories: 0.50 mL minimum volume, specimen stability (24 hours room temperature; 5 days refrigerated); (Adenovirus, Quantitative PCR | ARUP Laboratories Test Directory).
  • If your laboratory does not have an account with ARUP Laboratories or Quest Diagnostics or if you receive a specimen type for diagnostic testing but don’t have a test available, please notify ncirddvdgast@cdc.gov and diseases@aphl.org for assistance in coordinating the diagnostic testing.

• Respiratory specimen (nasopharyngeal swab in VTM/UTM, sputum, or bronchioalveolar lavage [BAL])
• Stool specimen (or rectal swab in VTM/UTM); whenever possible, a stool specimen is preferred to a rectal swab
• If a liver biopsy has already been performed as clinically indicated, or from native liver explant or autopsy:
  • Formalin-fixed, paraffin embedded (FFPE) liver tissue
  • Fresh liver tissue, frozen on dry ice or liquid nitrogen immediately or as soon as possible, and stored at ≤ -70°C
• If any adenovirus isolates are received or obtained through the culturing of clinical specimens related to the pediatric hepatitis cases, please notify CDC (ncirddvdgast@cdc.gov) for instructions on submission and additional characterization.

Adenovirus typing is a surveillance-use only test. Results will be reported back to the SPHL only.

• Aliquot for adenovirus typing (minimum volume = 0.5 mL)
• Store frozen (use ≤ -70°C if available).
• Submit specimens on dry ice to your state public health laboratory, including any local test results and a notification that these specimens are associated with the “Adenovirus/Hepatitis Investigation in Children.”
• Notify your State Epidemiologist POC and CDC (ncirddvdgast@cdc.gov) when you have specimens available from PUIs associated with this investigation.

• • CDC will provide detailed shipping instructions once notified.
  • Make sure to denote the diagnostic test results for adenovirus of each specimen, to ensure that adenovirus-positive specimens are properly identified for typing.

For epidemiologic purposes, test for past SARS-CoV-2 infection in children with acute hepatitis.

• Consider collecting and submitting the following specimen types (if available) for SARS-CoV-2 detection.
• Serology testing can identify past SARS-CoV-2 infection by detecting the presence of SARS-CoV-2 antibodies in serum or plasma components of blood.
• SARS-CoV-2 serology testing of plasma/serum are for surveillance-use only.
• Blood specimen collected in purple-top EDTA tube (plasma), gold-top or tiger- top tubes (serum)
• Stored frozen (use ≤ -70° if available).
• Submit specimens on dry ice to your state public health laboratory, including any local test results and a notification that these specimens are associated with the “Adenovirus/Hepatitis Investigation in Children.” Notify your State Epidemiologist POC and CDC (ncirddvdgast@cdc.gov) when you have specimens available from PUIs associated with this investigation.
  • CDC will provide detailed shipping instructions once notified.
  • Make sure to denote the diagnostic test results for adenovirus of each specimen, to ensure that adenovirus-positive specimens are properly identified for typing.

If a liver biopsy has already been performed as clinically indicated, or from native liver explant or autopsy:

• Acceptable sample criteria:
  • formalin-fixed, paraffin embedded (FFPE) liver tissue specimens that demonstrate histopathologic evidence of hepatitis, have been submerged in formalin for ≤2 weeks prior to embedding in paraffin

AND

• • are collected from pediatric patients with hepatitis of unknown etiology meeting the current outbreak case definition.

• In order to perform adenovirus PCR and SARS-CoV-2 RT-PCR, submission of FFPE tissue blocks is required. Unstained slides are not acceptable for molecular (PCR) testing, and tissue scrolls are not acceptable for any testing at IDPB.  For more information, see: Pathologic Evaluation of Fixed Tissues for Possible Infectious Etiologies (CDC-10365)
• Liver biopsies may be small specimens. To maintain specimen integrity, we recommend existing FFPE tissue blocks be submitted as is, and not be split, which might further reduce available tissue in the block.  FFPE tissue blocks that have been depleted due to removal of tissue sections from the block are not acceptable for testing and will be rejected.
• Please contact CDC’s IDPB (pathology@cdc.gov) upon receiving tissue specimens, for pre-approval and specific submission instructions. Do not send specimens until pre-approval is provided by pathology@cdc.gov.