التهاب الكبد ب

الحضانة: 45–180 يوماً. حاد: إرهاق، يرقان، ألم في المراق الأيمن. مزمن (بدون أعراض لعقود): تليف كبدي، سرطان الخلايا الكبدية. مظاهر خارج كبدية: التهاب الشرايين العقدي، التهاب كبيبات الكلى.

Risk factors for acquiring hepatitis B:

• Birth to an HBsAg-positive mother: The most important risk factor globally. Perinatal transmission leads to chronic infection in ~90% of cases. Without prophylaxis, 70–90% of infants born to HBeAg-positive mothers become infected.

• Unvaccinated status: Lack of vaccination is the primary modifiable risk factor. HBV vaccine is >95% effective at preventing infection.

• Healthcare workers and first responders: Occupational needlestick injuries carry a 6–30% HBV transmission risk from a single exposure to HBeAg-positive blood (compared to 0.3% for HIV).

• People who inject drugs (PWID): Sharing of needles, syringes, and drug preparation equipment. Prevalence of HBV markers reaches 40–60% in some PWID populations.

• Sexual transmission: Multiple sexual partners, men who have sex with men (MSM), and sexual contact with HBV-infected individuals. HBV is 50–100 times more infectious than HIV via sexual contact.

• Household contacts of chronically infected individuals: Sharing razors, toothbrushes, or contact with open wounds.

• Residence in or travel to endemic areas: Sub-Saharan Africa (6–8% prevalence), East Asia (5–7%), Southeast Asia (2–5%).

• Recipients of blood products or organ transplants in countries without universal screening.

• Hemodialysis patients: Impaired immune response leads to lower vaccine efficacy (60–70%) and higher infection risk.

Risk factors for progression to chronic infection:

• Age at infection: 90% chronicity in neonates; 30% in children aged 1–5; <5% in immunocompetent adults.

• Immunosuppression: HIV co-infection, chemotherapy, organ transplant recipients.

• Male sex: Males are more likely to remain chronically infected and develop HCC.

• تليف الكبد: يتطور لدى 15–25% من المصابين بعدوى مزمنة

• سرطان الخلايا الكبدية (HCC): HBV مسؤول عن ~54% من حالات سرطان الكبد عالمياً

• التهاب الكبد الخاطف: <1% من الحالات الحادة — نسبة وفيات 60–80% بدون زراعة كبد

• التهاب الكلية الغشائي والتهاب الأوعية العقدي: مظاهر خارج كبدية

• العدوى المزدوجة HBV/HDV: تسارع تطور المرض