Hepatitis A – Serology

Testing Indications

Testing for hepatitis A virus (HAV) serology may be indicated for the work-up of patients with suspected acute viral hepatitis to determine immune status (following recovery from natural infection or as a result of immunization), and as part of an epidemiologic investigation (e.g. outbreak investigation).

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Hepatitis A

Serum

Immunity 1.0mL

Diagnostic 2.0mL

Immunity+ Diagnostic 2.0mL

Serum Separator Tubes (SST)

Submission and Collection Notes

1

Detailed instructions for ordering HAV serology are available to assist with completing the “Hepatitis Serology” boxes in section 3 of the General Test Requisition.

2

Public Health Ontario (PHO) prefers centrifuged serum separator tubes for serological assays. Instructions for using SST tubes are found in the document titled: LAB-SD-008 Blood Collection Using Serum Separator Tubes (SST).

3

If testing for a combination of hepatitis virus markers, HIV, HTLV, syphilis and rubella, you are only required to submit one FULL 6 - 8.5 mL SST. If a full tube cannot be drawn, submit two tubes.

4

Do not submit glass tubes.

Limitations

Haemolysed, icteric, lipemic or microbially contaminated serum is not recommended for testing.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Centrifuge SST. Place specimen in biohazard bag and seal. Specimens should be stored at 2-8°C following collection and shipped to PHO’s laboratory on ice packs within 3 days of collection. Specimens received more than 7 days post collection will not be tested. If delayed shipping is anticipated, remove serum from clot and store frozen at -20°C or colder and ship on dry ice.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Testing is performed daily Monday to Friday.

Turnaround time is up to 3 days from receipt by PHO’s laboratory.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Positive HAV IgM results are reported to the Medical Officer of Health as per the Ontario Health Protection and Promotion Act.

Test Methods

Specimens for HAV serology are tested using a chemiluminescent microparticle immunoassay (CMIA) for the qualitative detection of IgG antibodies and IgM antibodies to human hepatitis A virus.

Algorithm

Refer to Hepatitis A – Serology Test Ordering Instructions for the testing algorithm for investigation of acute infection, immunity, and outbreak investigations.

All positive HAV IgM specimens are sent to the National Microbiology Laboratory for genotyping.

Interpretation

A positive result for HAV IgG (in the absence of HAV IgM) indicates immunity to HAV.

A positive result for HAV IgM with or without a positive HAV IgG suggests recent/acute infection with HAV. It may also be due to non-specificity of the test assay as a result of non-specific cross-reacting antibodies (e.g. rheumatoid factor, etc.). A positive HAV IgM must be interpreted with clinical symptoms and/or exposure history.

Hepatitis A – Genotyping/Subtyping

Hepatitis A - Genotyping-Subtyping

Mis à jour le 10 mars 2022