Hepatitis E ✅

Related Subjects: |Hepatitis A |Hepatitis E |Chronic liver disease |Liver Function Tests |Ascites Assessment and Management |Budd-Chiari syndrome |Alcoholism and Alcoholic Liver Disease |Liver Transplantation

⚠️ Hepatitis E virus (HEV) usually causes an acute, self-limiting hepatitis, but it can be severe in pregnancy, chronic liver disease and immunocompromised patients. In endemic regions it is often spread by contaminated water, while in the UK and Europe it is commonly linked to undercooked pork, pork liver, wild boar, venison and shellfish. HEV does not usually become chronic in immunocompetent people, but chronic HEV can occur after transplantation or other immunosuppression.

ℹ️ About Hepatitis E Virus

• 🦠 HEV is a non-enveloped, positive-sense, single-stranded RNA virus.
• 💩 It is transmitted mainly by the faeco-oral route.
• 🌍 Globally, contaminated drinking water is an important route of transmission, especially in areas with poor sanitation.
• 🇬🇧 In the UK, HEV is often zoonotic and foodborne, especially from undercooked pork products.
• ✅ Most infections are self-limiting and resolve within weeks.
• ⚠️ Severe hepatitis and acute liver failure are more likely in pregnancy, chronic liver disease and immunosuppression.
• 🔁 Chronic HEV is mainly seen in immunocompromised patients, especially solid organ transplant recipients.

🧬 Genotypes - Why They Matter

🌍 Epidemiology & Transmission

• 💧 Waterborne: contaminated drinking water in areas with poor sanitation; may cause large outbreaks.
• 🥩 Foodborne zoonotic: undercooked pork, pork liver, wild boar, venison and shellfish.
• 💩 Faeco-oral: contaminated hands, food or water.
• 🩸 Bloodborne: transfusion-related transmission is rare but recognised.
• 👶 Vertical transmission: can occur in pregnancy and is associated with adverse fetal outcomes in severe maternal infection.
• 🧑‍⚕️ High-risk groups include pregnant women, people with chronic liver disease, transplant recipients and other immunocompromised patients.

🧠 Pathophysiology

• HEV enters via the gut and reaches the liver through the bloodstream.
• The virus replicates in hepatocytes and is excreted in bile, then shed in stool.
• Liver injury is largely immune-mediated, causing hepatocellular inflammation and raised ALT/AST.
• In immunocompromised patients, inadequate viral clearance can allow persistent HEV replication and chronic hepatitis.
• Pregnancy-related immune and hormonal changes may partly explain the high severity reported with HEV-1 and HEV-2 infections.

🩺 Clinical Features

• ⏱ Incubation is usually around 2–8 weeks.
• 🤒 Prodrome: fever, malaise, anorexia, nausea, vomiting and abdominal discomfort.
• 🟡 Icteric phase: jaundice, dark urine, pale stools and pruritus.
• 🫀 Examination may show tender hepatomegaly.
• 🚬 Aversion to cigarettes is a classic viral hepatitis clue, but it is not specific.
• 🧠 Extrahepatic features can occur, especially neurological complications such as neuralgic amyotrophy, Guillain-Barré syndrome or meningoencephalitis.
• 🔁 Immunocompromised patients may have persistent viraemia, chronic hepatitis and progressive fibrosis.

⚠️ Severe Disease Risk

• Pregnancy: severe disease is particularly associated with HEV-1 and HEV-2 in endemic regions; third trimester infection has historically been associated with high maternal mortality.
• Chronic liver disease: acute HEV can precipitate hepatic decompensation.
• Immunocompromised patients: HEV can persist and become chronic.
• Older adults and comorbidity: may have more severe symptomatic disease.

🚩 Red Flags - Urgent Assessment

• 🧠 Confusion, drowsiness, encephalopathy or reduced consciousness.
• 🩸 Raised INR, bleeding tendency or suspected acute liver failure.
• 🟡 Rapidly worsening jaundice or very high transaminases with systemic illness.
• 🤮 Persistent vomiting, dehydration or inability to maintain oral intake.
• 🤰 Pregnancy, especially second or third trimester.
• 🛡 Immunosuppression, transplant history or advanced HIV.
• 🫀 Known chronic liver disease, cirrhosis or hepatic decompensation.

🔎 Investigations

• Anti-HEV IgM: suggests recent or acute HEV infection.
• Anti-HEV IgG: suggests previous exposure; may persist after infection.
• HEV RNA PCR: confirms active infection and is especially useful in immunocompromised patients, where antibody responses may be weak or delayed.
• Liver blood tests: ALT/AST often markedly raised; bilirubin may be raised; ALP/GGT may be mildly raised.
• Coagulation: check PT/INR if jaundiced, pregnant, unwell, immunocompromised or chronic liver disease.
• U&E and glucose: assess dehydration, renal function and severity.
• Screen for other causes: HAV, HBV, HCV, EBV/CMV, autoimmune hepatitis, drug-induced liver injury and biliary obstruction if clinically indicated.
• Fibrosis assessment: consider elastography or specialist assessment in chronic HEV or underlying liver disease.

🧪 Serology & PCR Interpretation

💊 Management - Acute HEV

• Supportive care: rest, hydration, nutrition and antiemetics if required.
• 🍷 Avoid alcohol until recovered.
• 💊 Avoid unnecessary hepatotoxic drugs; be cautious with paracetamol and NSAIDs in significant hepatitis or liver dysfunction.
• 📈 Monitor LFTs and INR if symptomatic, jaundiced, pregnant, immunocompromised or chronic liver disease.
• 🚑 Admit or urgently refer if acute liver failure, coagulopathy, encephalopathy, severe vomiting, dehydration, pregnancy with significant hepatitis, or chronic liver disease with decompensation.

🛡 Management - Immunocompromised / Chronic HEV

• 👨‍⚕️ Refer to hepatology or infectious diseases.
• 🧪 Confirm persistent infection with serial HEV RNA.
• 💊 Reduce immunosuppression where safe, especially in transplant patients, under specialist guidance.
• 💊 Ribavirin may be used for chronic HEV in selected immunocompromised patients under specialist supervision.
• 🚫 Ribavirin is teratogenic and is contraindicated in pregnancy.
• 📈 Monitor viral clearance, ALT, fibrosis progression and relapse risk.

🤰 Pregnancy

• Pregnancy, especially later pregnancy, is a high-risk setting for severe HEV in endemic-region infections.
• Pregnant patients with suspected HEV should have urgent obstetric and hepatology/infectious diseases input.
• Check LFTs, bilirubin, INR, glucose, renal function and full clinical severity assessment.
• Management is mainly supportive; ribavirin is contraindicated.
• Monitor closely for acute liver failure, hypoglycaemia, coagulopathy, fetal compromise and obstetric complications.

🏥 Public Health & Infection Control

• 🧼 Hand hygiene after toileting and before preparing food is essential.
• 🍽 Avoid preparing food for others during the early illness period.
• 🤰 Limit contact with pregnant women and people with chronic liver disease during early illness where possible.
• 📋 Take a careful food, travel, occupational and animal exposure history.
• 🧑‍⚕️ Follow local health protection advice for outbreaks, food handlers and vulnerable contacts.

🚰 Prevention

• 🚰 Safe water, sanitation and hand hygiene reduce outbreaks in endemic regions.
• 🥩 Cook pork, pork liver, wild boar, venison and sausages thoroughly until piping hot, no pink meat remains and juices run clear.
• 🦪 Avoid raw or undercooked shellfish, especially if pregnant, immunosuppressed or chronic liver disease.
• ✈️ Travellers to endemic areas should avoid unsafe water, ice, unwashed salad and undercooked food.
• 💉 Hepatitis B vaccination prevents HDV, but does not prevent HEV.
• 💉 An HEV vaccine exists in China, but it is not widely available internationally or routinely used in the UK.

📝 Exam Pearls

• 💩 HEV is faeco-orally transmitted, classically waterborne in endemic regions.
• 🥩 In the UK/Europe, think zoonotic foodborne HEV from undercooked pork or game.
• 🤰 HEV can be dangerous in pregnancy, especially genotype 1 or 2 infection in later pregnancy.
• 🛡 Chronic HEV occurs mainly in immunocompromised patients.
• 🧪 Anti-HEV IgM suggests recent infection; HEV RNA confirms active viraemia.
• 🚫 HEV is not prevented by hepatitis B vaccination.
• 💊 Ribavirin may be used for chronic HEV under specialist care but is contraindicated in pregnancy.

🧠 Teaching Note

HEV behaves differently depending on host immunity, pregnancy status and genotype. In immunocompetent adults it usually causes a self-limiting acute hepatitis, similar to HAV. In pregnancy, particularly with HEV-1 and HEV-2 in endemic settings, the risk of fulminant hepatic failure is much higher. In immunocompromised patients, failure to clear the virus can lead to persistent viraemia, chronic hepatitis and progressive fibrosis.

📚 References & UK Resources

• UKHSA – Hepatitis E symptoms, transmission, treatment and prevention
• Food Standards Agency – Hepatitis E and food safety
• WHO – Hepatitis E
• British Liver Trust – Hepatitis E
• UK SMI / RCPath – Screening and monitoring for HEV infection