Hepatitis B Envelope Antigen (HBeAg)
The "Viral Activity" & Infectivity Monitor
The Hepatitis B Envelope Antigen (HBeAg) test is a specific blood marker used to measure how actively the Hepatitis B virus is multiplying inside your body.
While the standard screening test (HBsAg) tells us the virus is present, the HBeAg tells us if the virus is working overtime.
- HBsAg: "The intruder is in the house."
- HBeAg: "The intruder is actively making copies of himself."
A positive HBeAg result generally indicates high viral replication, meaning the viral load is high and the person is highly contagious to others.
Why Do You Need This Test?
This test is typically ordered only after a person has already tested positive for Hepatitis B. Doctors use it to answer three critical questions:
"How Contagious Am I?"
- HBeAg is a marker of infectivity. If you are positive, the risk of spreading the virus through sex or blood contact is much higher.
"Will I Pass It to My Baby?"
- Pregnancy Screening: This is the most critical test for pregnant women with Hepatitis B. If a mother is HBeAg Positive, there is a 90% chance she will pass the virus to her baby during birth unless specific preventive steps (vaccine + immunoglobulin) are taken immediately.
"Is My Medication Working?"
- For patients on antiviral therapy, the goal is often to make HBeAg disappear (Seroconversion). Regular testing tracks this progress.
