Exam Cram

• Infections of liver caused by viruses: Hepatitis A, B, C, D, E

• Vaccines for Hepatitis A & B

• Hepatitis A &E faecal oral route, Hep B, C, D blood route

• Hepatitis B vaccine produced HBsAg

• Hepatitis C has a 99% cure rate with antivirals

Hepatitis A

Background

• Transmission- faecal oral route

• Single stranded RNA

• Commonest hepatitic virus worldwide, more common with poor hygiene standards

• Usually self limiting, 1% deaths of viral hepatitis

• Maximum incubation period is 6m

History & Examination

• Fever, diarrhoea, anorexia, 

• Jaundice, abdominal pain

Investigations

• HAV PCR (diagnostic)

• LFTs, Coag, FBC, EUC,

• Hepatitis screen & liver USS

Management

• Vaccination

• Anti-virals available but usually not necessary

Hepatitis B

Background

• Double stranded DNA virus

• Transmission: blood

• 5% adults and 90% children progress to chronic infection -> cirrhosis and HCC

• Causes polyarteritis nodosa & membranous nephropathy

Presentation

• BBV risk factors: sexual, tattoes

• Vertical transmission

• Presentation:

  • 1% fulminant liver failure

Investigations

Antibody

• HBsAb:

  • positive = previous vaccination or infection

  • negative = nil vaccination

• Anti HBcAb- from current or previous infection

  • IgG- infection > 6m ago, potentially cleared

  • IgM- infection within 6 months

• AntiHBeAb- positive = active infection, negative = cleared infection

Antigen

• HBsAg- states whether currently infectious, either active or chronic infection

• HBcAg- positive = if ever been infected- current or previous infection

• HBeAg- positive = highly infectious

Presentations

• Nil infection/ vaccination: negative throughout

• Immune due to vaccination: antiHBsAg only 

• Cleared infection:  AntiHBsAg, AntiHBcAg IgG (if > 6m nil anti-HBcAg IgM)

• Active infection: antiHBcAg (IgM & IgG), HBcAg & HBsAg; nil antiHBsAg (B cell dysfunction)

• Chronic infection: AntiHBcAg & HBsAg

Management

• Tenofovir, interferon: not curative

• Vaccination indications

  • UK Childhood vaccination schedule

  • Healthcare workers with risk of needlestick injuries

Needle stick injuries

• HBV: 0.3% 

• High risk events (needlestick in known or high risk HBV)

  • Give HBV immunoglobulin within first 12 hours, nil value > 7d

  • Test for HBV

  • Consider PEP

• Low risk events- minimal needlestick in low risk individual: 

  • Test for HBV

  • Await PEP till after tests

Hepatitis C

Background

• Single stranded RNA virus

• No vaccine available 

• Transmitted through blood (BBV)

• 20% develop acute hepatitis, but 70% develop chronic disease

• x6 subtypes- dictates treatment

• Causes: Cryoglobulinemia 

Diagnosis: 

1. Screening: anti HCV antibody

2. Diagnosis: HCV PCR

Presentation

• Signs of liver cirrhosis

• Can also be asymptomatic

Investigations

• Anti HCV antibody +ve

• HCV PCR +ve

Management

• 99% cure rate with anti viral for 12 weeks

• Test of cure 12 weeks after completion

• Biggest issue is compliance

• AUSS required to distinguish whether liver cirrhosis presence, dictating choice of anti-viral

Needle stick injuries

• • Needle stick risk of contamination- HCV: 3% 

  • Initial Management

    • Viral load HCV RNA

    • Repeat viral load 4 weeks later

    • Start treatment if viral load not markedly improved after 4 weeks

This is because a significant proportion of HCV is cleared by the body in the acute phase

• Treatment

  • 12 weeks antiretrovirals

  • Test of cure (HCV PCR) 12 weeks post treatment

Deeper Dive

Management

Ledipasvir/ sofosbuvir- if concomitant Cryoglobulinemia 

Hepatitis D

• Transmission: blood borne

• Requires current HBV infection to for superimposed infection

• Nil vaccination

Hepatitis E

• Transmission: faecal-oral route, typically from pigs

• No vaccination (common MCQ HAV vs HEV in vaccination = HEV)

• No treatments

• Mortality can reach 20% in pregnancy, 1% ouside of pregnancy

• Common in south and central Asia, Middle East & Africa

Post exposure prophylaxis

Three drug anti-retroviral prophylaxis for one month

Needle stick risk of contamination

• HIV: 30%

Management

High risk events- needlestick in known HBV or HIV: start PEP & test

Low risk events- minimal needlestick in low risk individual: treat & await PEP till after treatment

Medical Registrar Notes

Other viral causes of hepatitis

• EBV 

• CMV

References

1. Hepatitis A and E – Differences and commonalities
   Gotlieb, Neta et al.
   Journal of Hepatology, Volume 72, Issue 3, 578 - 580

Written in 2025.