Viral Hepatitis Flashcards
Hepatitis A: Virology & Epidemiology
- Non-enveloped positive stranded RNA virus.
- Spread by faeco-oral route e.g. contaminated water.
- Waterborne epidemics.
- Sporadic infections from shellfish.
- Endemic in countries with poor hygiene and sanitation.
- Bloodborne transmission is rare.
Hepatitis B: Virology & Epidemiology
- Partially double stranded DNA virus.
- Highest prevalence in Africa, Asia, and the West Pacific Rim.
- Also common in Southern and Eastern Europe.
- Bloodborne virus.
- Transmission - unprotected sex, contaminated needles, breaks in mucous membranes, blood transfusion and from mother to child.
Hepatitis C: Virology & Epidemiology
- Most common cause of chronic viral hepatitis.
- Enveloped single stranded RNA virus.
- Africa, Asia, Southern and Eastern Europe most affected.
- Bloodborne virus.
- Transmission - contaminated needles, blood transfusions, unprotected sex, breaks in mucous membranes and from mother to child.
Hepatitis D: Virology & Epidemiology
- RNA virus.
- Only possible to be infected if you already have Hepatitis B.
- Seen in Amazonian basin, Central Africa and Middle East.
- Bloodborne virus.
- Transmission associated with IV drug use.
Hepatitis E: Virology & Epidemiology
- RNA virus Zoonotic disease.
- More common in middle aged men.
- Epidemics in Asia and India.
- Associated with pig farming/consumption of pork.
- Spread via faeco-oral route.
Hepatitis A: Presentation
- Hepatomegaly - 80%
- Jaundice - 70%
- Fatigue
- Arthralgia (joint stiffness)
- Poor appetite
Hepatitis B: Presentation
-Asymptomatic - 66%
Of those with symptoms;
- Jaundice - 90%
- Poor appetite
- Myalgia
- Fever
- Tender hepatomegaly
Severity of HBV is based on immune response.
Hepatitis C: Presentation
- Asymptomactic (during acute phase) - 85%
- Poor appetite
- Myalgia
- Fever
- Jaundice
- Tender Hepatomegaly
Hepatitis D: Presentation
Cannot distinguish between Hepatitis B and D.
Hepatitis E: Presentation
95% are asymptomatic. Typically, males over 50 are most severely affected.
Symptoms include diarrhoea, vomiting, fevers, neurological symptoms (10%).
Hepatitis A: Investigations
- HepA IgM - positive in acute infection
- HepA IgG - indicates immunity
Hepatitis B: Investigations
- HBsAg - + during acute and chronic infection.
- Anti sAb - + following previous infection and after vaccination.
- HBeAg - + during acute infection. Indicates high viral replication. Sometimes + during chronic infection.
- Anti eAb - sometimes indicates reduction in viral replication and transmissibility in chronic infection.
- Anti HBc IgM - + during acute infection.
- Anti HBc IgG - + during chronic infection and recovery.
- HBV-DNA - quantifies viral load in chronic infection.
Hepatitis C: Investigations
- Hepatitis C RNA - active infection
- Anti-Hepatitis C antibody - recovery or chronic infection.
Hepatitis D: Investigations
- Hepatitis D IgM - acute infection.
- Hepatitis D IgG - indicates immunity.
Hepatitis E: Complications
- Usually self-limiting
- Most common cause of acute hepatitis in UK
- 25% of pregnant women die.
Hepatitis A: Prevention and Treatment
- Vaccine
- Self-resolving infection
- Supportive treatment
- 0.1-0.3% develop acute liver failure leading to transplant.
- No cases of chronic Hepatitis A
- Once infected, develop lifelong immunity.
Hepatitis B: Prevention and Treatment
- Vaccine - babies vaccinated at 8, 12 and 16 weeks. Other reasons to vaccinate include uninfected household contacts, lifestyle risk, co-existing medical conditions, occupational or travel risk.
- NO CURE - viral suppression
- Nucleotide Analogues - inhibit RNA polymerase, taken in tablet form, well tolerated, lifelong duration of treatment. - Entecavir, Tenofovir, Lamivudine
- Pegylated Alpha Interferons - stimulate activation of genes involved in immunity, given by subcutaneous injection, flu like side effects, 48 week duration of treatment.
Hepatitis C: Prevention and Treatment
- No vaccine available due to rapid emergence of variants.
- Direct acting antivirals - highly effective new treatment.
- Treatment for 12-24 weeks.
- Cure achieved in 95%.
- Protease inhibitors - Paitaprevir
- NS5A Inhibitors - Ledipasivir
- RNA Polymerase Inhibitors - Sofobuvir
Hepatitis D: Prevention and Treatment
- Antivirals used for treatment of HepB do not work for HepD.
- Pegylated Interferons are the only treatment options.
Hepatitis E: Prevention and Treatment
- Vaccine for HepE available but only licensed for use in China.
- Supportive Care
Hepatitis B: Complications
Cirrhosis, Hepatocellular Carcinoma, Fulminant Hepatitis.
Complications of HBV are due to host T cell activity. The better the immune response, the more damage to hepatocytes.
Extrahepatic manifestations of Hepatitis C
Thyroid disease, lymphoma, fibrosis, membranous proliferative glomerulonephritis, lichen planus, porphyria cunea tardiq.
Hepatitis D: Complications
Co-infection with HBV and HDV represemts the most severe form of hepatitis due to rapid progression of the disease and development of hepatocellular carcinoma.
