Guidance for Clinicians

Testing of Pediatric Patients with Hepatitis of Unknown Etiology

A clinical workup for children with acute hepatitis should be done locally per treating clinicians. CDC recommends testing for adenovirus and SARS-CoV-2.

Contact your State Public Health Lab for instructions on where to send specimens.

Testing for Adenovirus
  • 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. polymerase chain reaction [PCR]) is preferred. Whole blood by PCR may be more sensitive than testing plasma or serum.
  • Respiratory specimen (nasopharyngeal swab in viral transport media/universal transport media [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 tissue is available from a 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.
Testing for SARS-CoV-2

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

  • 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.
    • For vaccinated children, order a SARS-CoV-2 serology test that specifically measures anti-nucleocapsid antibodies.
    • For unvaccinated children, it is possible to order a SARS-CoV-2 serology test that specifically measures anti-spike or anti-nucleocapsid antibodies.
  • Blood specimen collected in purple-top EDTA tube (plasma), gold-top or tiger-top tubes (serum).
Instructions for Laboratories

Detailed instructions for laboratory testing, typing, and submission can be found on the Laboratory Testing page. Instructions for both local/clinical laboratories and state public health laboratories (SPHL) are included.

Laboratory Instructions for Testing >>
Page last reviewed: June 22, 2022