Hepatitis B

Hepatitis B is caused by HBV; clinical features: fatigue, anorexia, nausea/vomiting, aversion to fat, hepatomegaly, abnormal LFTs. Some have fever/jaundice; a minority become chronic → cirrhosis/liver cancer; severe cases = fulminant hepatitis; others = asymptomatic carriers.

Common Symptoms

HDAg...; HBV-HCV...; UGI bleeding; ascites; liver-qi stagnation; fatigue; nausea; epistaxis

Causes and Pathogenesis

Transmission: unsterilized syringes/needles/dental instruments; shared needles in drug users; perinatal (HBeAg-positive mothers); sexual contact with carriers; blood/blood products. Pathogenesis: T-cell-mediated hepatocyte injury (not direct viral cytopathy). (1) Acute: normal immune → Tc cells kill infected cells; antibodies + interferon clear HBV → recovery. (2) CAH: immune defect → insufficient Tc/antibodies; persistent replication; autoantibodies to Lsp cause ADCC. (3) CPH/asymptomatic carrier: weak immune response; no/light injury. (4) Fulminant: over-strong immune response → massive hepatocyte necrosis; Arthus/Schwartzman reactions; TNF-α/IL-1/leukotrienes. Pathology: diffuse hepatic degeneration/necrosis/inflammation/regeneration/fibrosis.

Treatment

Drug therapy, supportive therapy

Preventive Measures

(1) Isolation not strictly required; discharge when LFT stable; regular follow-up; health checks for food handlers/childcare workers; screen blood donors. Carriers: no food/childcare/blood work, but can otherwise work; personal items separate. (2) Disposable syringes; sterilize blood-contaminated items; blood-product management. (3) Vaccination: 0-1-6 month IM deltoid schedule; plasma-derived 10-30 µg, recombinant 5-10 µg; anti-HBs >10 U/L protective; larger doses for dialysis/immunocompromised. HBIG for infants of HBeAg-positive mothers, 0.075-0.2 mL/kg, combined with vaccine.

Department to Visit

It is recommended to visit the Hepatology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.