Hepatitis B – Genotyping

Testing Indications

• Hepatitis C virus (HCV) genotyping is tested in conjunction with a detected HCV RNA viral load.
• All specimens submitted for HCV RNA viral load without a previous HCV genotype that meets HCV genotype testing requirements will be automatically tested for HCV genotype.
• HCV genotyping will be automatically repeated for patients with suspected HCV reinfection (as indicated on the test requisition), as long as the HCV viral load meets the testing requirements.

Limitations

Haemolysed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing.

Storage and 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.

Special Instructions

Centrifuge the SST/EDTA tube and transfer serum/plasma to a cryovial. Store serum/plasma specimen frozen at <-60°C following collection.  Place specimen in biohazard bag and seal. Ship to PHOL frozen on dry ice or ice packs.

Test Frequency and Turnaround Time (TAT)

Hepatitis B - genotyping specimens are shipped to NML biweekly. 

Turnaround time is up to 21 days

Hepatitis B - Genotyping Test is referred to the National Microbiology Lab (NML) in Winnipeg.

Hepatitis B serology and DNA results – Serology results must show markers to Hepatitis B virus and HBV DNA results must have detectable viral load.

Hepatitis B Genotype testing is performed by conventional Polymerase Chain Reaction (PCR) followed by 1) line probe hybridization assay in which reactivity to genotype specific probes indicates the HBV genotype(s), or 2) sequence and phylogenetic analysis in comparison to HBV genotype reference sequences.

Reporting

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

References

LAB-SD-031, Hepatitis B (HBV) DNA Testing and Interpretation update