Laboratory Test Reference Guide

Hepatitis B status includes Hepatitis B s Ag, Hepatitis B s Ab and Hepatitis B core Ab.

Further tests will be performed as required.

• Clinicians should try to identify patients with raised LFTs due to chronic  viral hepatitis,
• All HBsAg-positive pregnant women should have their HBV viral load measured,
• All HCV PCR-positive patients should be referred to a specialist, for consideration of treatment with oral direct acting antiviral therapies (DAA).
• New Zealand wide Many HBsAg-positive patients are not being properly followed up or referred, and stand the risk of developing preventable liver disease.
• HBsAg is present in almost all actively infected persons with HBV and is the first test that should be requested if HBV infection is suspected.
• HBV surface antibody is a test that should really only be ordered for adults in occupational health settings, preferably within a few months of the final dose of vaccine: those who develop a clear response will be protected for life.
• HBV e antigen predicts high titres of virus, but its absence does not exclude high viral loads, especially in adults who were infected in childhood.
• HBV DNA measurement is an essential part of assessment and management

Note: Waikato DHB Laboratory screen with HBsAg, anti-HBs and anti-HBc to reduce the need for repeat testing. HBc IgM may help in selected cases for Public Health to determine if the infection is acute.