HEPATITIS B SURFACE ANTIGEN, CONFIRMATION, SERUM

Hepatitis B Surface Antigen, Confirmation, Serum

What it is

The Hepatitis B Surface Antigen (HBsAg) Confirmation test is a specialized laboratory assay performed on serum to verify whether an initially positive HBsAg screening result truly represents hepatitis B infection. Screening tests such as rapid card tests or ELISA may occasionally give false-positive results due to cross-reactivity, technical error, or other factors. The confirmation test uses more specific methods (e.g., neutralization assays or advanced immunoassays) to ensure accurate diagnosis.

Uses

This test is used to:

• Confirm a positive HBsAg screening result.
• Distinguish true hepatitis B infection from false-positive screening results.
• Ensure accurate diagnosis before beginning treatment or counseling.
• Support decisions regarding blood donor eligibility, pre-surgical screening, or pregnancy monitoring.

Symptoms That May Lead to the Test

Patients usually undergo HBsAg confirmation after a preliminary test indicates possible infection. It is especially recommended if there are symptoms of hepatitis such as jaundice, fatigue, dark urine, pale stools, abdominal pain, nausea, or elevated liver enzymes. Asymptomatic individuals may also require confirmation if they tested positive in screening programs (e.g., for blood donation, preoperative checks, or prenatal care).

Abnormal Results

Confirmed Positive HBsAg: Indicates active hepatitis B infection (acute or chronic). Further evaluation with HBV DNA, HBeAg, and antibody testing is required to determine disease phase and infectivity.

Confirmed Negative HBsAg: Suggests that the initial positive was a false positive; the person does not have hepatitis B infection. If risk factors are present, follow-up testing may still be advised.

Risks

The confirmation test requires a routine blood sample. Risks are minimal, including slight pain, bruising, or dizziness at the puncture site, which usually resolve quickly. The confirmation process itself has no direct risks beyond the blood draw.