Viral Hepatitis Exposure
Hepatitis virus enters the bloodstream and reaches the liver.
- 60–150: Incubation (Hep B) (days average)
- 14–84: Incubation (Hep C) (days average)
- Liver: Primary target organ (hepatocytes infected)
- 3+: Transmission routes (blood, sexual, perinatal)
How infection begins
Virus particles enter hepatocytes and begin replicating.
Age at exposure matters
Younger age at infection raises chronic Hepatitis B risk.
Virus type matters for C
Hepatitis C often turns chronic regardless of age.
Acute Immune Response
The immune system detects infected hepatocytes and mobilizes.
- Day 30–60: Peak viral load (post-exposure)
- 10–100×: ALT enzyme spike (normal levels)
- ~4–6 wk: T-cell response onset (after exposure)
- ~30%: Symptomatic adult Hep B (jaundice, fatigue)
Cytotoxic T cells activate
CD8+ T cells target infected hepatocytes directly.
Liver inflammation rises
Immune attack elevates liver enzyme levels.
Antibody production begins
B cells start producing neutralizing antibodies.
Clearance or Persistence
Immune strength decides whether the virus is eliminated.
- ~95%: Adult Hep B clearance (rarely chronic)
- ~10%: Infant Hep B clearance (mostly chronic)
- ~20–25%: Hep C clearance (any age) (spontaneous)
- ~75–80%: Chronic Hep C rate (across all ages)
Age drives Hep B outcome
Immature infant immunity favors chronic infection.
Hepatitis C resists clearance
Rapid viral mutation evades antibody responses.
A probabilistic fork
Clearance probability sets which path unfolds.
Acute Resolution
The virus is fully cleared and lasting immunity remains.
- ~95%: Anti-HBs seroconversion (acute adult Hep B)
- ~16 wk: Enzyme normalization (after resolution)
- Yes: Lifelong immunity (for resolved Hep B)
- Very Low: Reinfection risk (protective antibodies)
Virus is eliminated
Hepatocytes clear infection completely within months.
Memory cells remain
Long-lived immune memory prevents future infection.
Liver function recovers
Inflammation subsides and enzymes normalize.
Chronic Progression
Persistent virus drives ongoing liver inflammation and damage.
- ~254M: Chronic Hep B carriers (WHO estimate)
- ~50M: Chronic Hep C carriers (WHO estimate)
- ~20%: Cirrhosis risk (20yr) (untreated chronic cases)
- ~100×: Liver cancer risk (vs uninfected)
Virus persists low-level
Immune system fails to fully eliminate the virus.
Chronic inflammation builds
Ongoing damage gradually causes liver fibrosis.
Long-term risks rise
Cirrhosis and liver cancer risk climb over decades.