Viral hepatitides

💡 Viral hepatitis = inflammation of the liver caused by hepatotropic viruses (HAV, HBV, HCV, HDV, HEV). Some forms are acute and self-limiting, others progress to chronic hepatitis, cirrhosis, and hepatocellular carcinoma. 👉 Always consider viral hepatitis in patients with jaundice, deranged LFTs, or risk factors (blood, travel, IVDU).

📖 About

• Acute or chronic liver inflammation caused by viral infection.
• Histology: hepatocyte necrosis, ballooning, lobular inflammation.
• Some viruses (HAV, HEV) → acute, self-limiting. Others (HBV, HCV, HDV) → risk of chronicity.

🧬 Types of Viral Hepatitis

🩺 Clinical Features

• Non-specific: malaise, anorexia, nausea, fatigue 🤢
• Classic: jaundice, dark urine, pale stools, RUQ discomfort
• Hepatomegaly, tender liver
• Severe: confusion, encephalopathy, ascites, bleeding → acute liver failure 🚨

🔎 Investigations

• LFTs: ALT/AST often >1000 IU/L, ↑ bilirubin, prolonged PT/INR.
• Serology: – HAV IgM (acute infection). – HBsAg (active infection), anti-HBs (immunity), anti-HBc IgM/IgG. – Anti-HCV, HCV RNA PCR. – HDV antibody/antigen (if HBV positive). – HEV IgM (acute infection).
• Viral load (HBV DNA, HCV RNA) → guides treatment.
• USS/CT: exclude obstruction, assess chronicity/cirrhosis.
• Liver biopsy: staging chronic hepatitis (less common now with elastography).

💊 Management

• General supportive: Rest, hydration, nutrition, avoid alcohol and hepatotoxic drugs (esp. paracetamol).
• HAV/HEV: Self-limiting; supportive care only.
• HBV: – Acute: supportive (most recover). – Chronic: consider antivirals (tenofovir, entecavir) if high viral load or cirrhosis.
• HCV: Direct-acting antivirals (DAAs) cure >95% of cases.
• HDV: Difficult to treat; pegylated interferon may help. Prevent with HBV vaccination.
• Fulminant hepatitis: Urgent referral to transplant centre 🏥.

🛡 Prevention

• HAV: vaccination, food/water hygiene.
• HBV: universal vaccination (UK since 2017), safe sex, safe needles.
• HCV: harm reduction (needle exchange), blood donor screening. No vaccine yet.
• HDV: HBV vaccination prevents coinfection.
• HEV: safe water supply, avoid undercooked pork in high-risk groups.

🎯 Exam Pearls

• HAV/HEV = acute only; HBV/HCV/HDV = risk of chronicity.
• HBsAg = infection; Anti-HBs = immunity.
• HCV → high chronicity, but now curable with DAAs.
• HEV = dangerous in pregnancy (high mortality).
• Acute liver failure = urgent transplant referral 🚨.

🦠 Case 1 — Acute Hepatitis A

A 23-year-old backpacker returns from Southeast Asia with 2 weeks of malaise, anorexia, and jaundice. Examination shows tender hepatomegaly. 💡 Hepatitis A is an RNA virus spread by the faeco-oral route, often linked to travel or contaminated food. It causes acute, self-limiting hepatitis with no chronic phase. Management is supportive, and vaccination is effective for prevention in at-risk travellers.

🦠 Case 2 — Chronic Hepatitis B

A 34-year-old man originally from sub-Saharan Africa is found to have abnormal LFTs on routine blood tests. He is asymptomatic but HBsAg positive for over 6 months. 💡 Hepatitis B is a DNA virus transmitted via blood and body fluids. Chronic infection is common in those infected perinatally or in childhood and may progress to cirrhosis and hepatocellular carcinoma. Management includes antiviral therapy (e.g. tenofovir, entecavir) and monitoring for complications.

🦠 Case 3 — Chronic Hepatitis C

A 48-year-old man with a history of intravenous drug use presents with fatigue, arthralgia, and mildly raised transaminases. Hepatitis C antibody and RNA are positive. 💡 Hepatitis C is an RNA virus transmitted mainly via blood exposure. It frequently becomes chronic and can lead to cirrhosis and hepatocellular carcinoma. Modern management involves direct-acting antivirals, which can achieve sustained virological response (cure) in most patients.

🦠 Case 4 — Acute Hepatitis E

A 30-year-old pregnant woman presents with jaundice, malaise, and abdominal discomfort after recent travel to South Asia. LFTs show marked transaminase rise. 💡 Hepatitis E is an RNA virus spread faeco-orally, often via contaminated water. In most patients it is self-limiting, but in pregnancy it carries a high risk of fulminant hepatitis and maternal mortality. There is no specific treatment beyond supportive care and prevention through improved sanitation.