Indicator of viral replication in Hepatitis B infection is
Hepatitis B e antigen (HBeAg) is a marker of active viral replication. Its presence indicates that the virus is producing a lot of viral particles, making the patient more infectious. The other markers like HBsAg is the surface antigen, which is present in both acute and chronic phases. Anti-HBc is the antibody to core antigen, indicating past or ongoing infection. HBV DNA is the direct measure of viral load.
So the correct answer should be HBeAg. The options might include HBeAg as one of them. Let me check the possible distractors. Other options could be HBsAg, anti-HBe, or anti-HBs. HBsAg is the surface antigen, present in both acute and chronic phases but doesn't indicate replication. Anti-HBe is the antibody to e antigen, which appears when HBeAg disappears, indicating lower replication. Anti-HBs is the protective antibody from vaccination or recovery.
The clinical pearl here is that HBeAg is a marker of active replication, so its presence correlates with high infectivity and viral load. Also, in some cases, patients might have a mutant form where HBeAg is negative but still have active replication, so HBV DNA testing is more accurate. But for standard exams, HBeAg is the answer.
**Core Concept**
Hepatitis B infection markers include antigens, antibodies, and viral load indicators. **HBeAg** (Hepatitis B e antigen) is the primary serological marker of active viral replication, reflecting high infectivity and elevated HBV DNA levels.
**Why the Correct Answer is Right**
HBeAg is a soluble protein secreted during active HBV replication. Its presence indicates high viral load, increased risk of transmission, and active liver inflammation. It correlates with elevated HBV DNA levels and is a key target for monitoring treatment response in chronic HBV.
**Why Each Wrong Option is Incorrect**
**Option A:** HBsAg (surface antigen) indicates current infection but does not specifically reflect replication status.
**Option B:** Anti-HBe (antibody to e antigen) signals reduced replication, not active viral production.
**Option C:** Anti-HBc (antibody to core antigen) indicates past or chronic infection but is not replication-specific.
**Option D:** Anti-HBs (antibody to surface antigen) confirms immunity via vaccination or resolved infection.
**Clinical Pearl / High-Yield Fact**
HBeAg positivity is a classic exam trap: remember it signifies replication, while anti-HBe positivity suggests lower infectivity. In treatment, HBeAg seroconversion (HBeAg loss + anti-HBe) is a key endpoint.
**Correct Answer: C. HBeAg**