Hepatitis and Liver Failure in Dentistry

Hepatitis and Liver Failure in Dentistry

• Hepatitis and liver failure can lead to various complications, including:
  • Haemorrhagic tendencies
  • Impaired drug metabolism
  • Transmission of viral hepatitis
  • Cutaneous manifestations (purpura, telangiectasia, finger clubbing)
  • Sialadenosis
  • Sjogren's syndrome

Common Liver Diseases

• 6 common liver diseases:
  • Alcohol cirrhosis
  • Non-alcoholic fatty liver disease (obesity)
  • Viral hepatitis
  • Drug toxicity
  • Liver cancer
  • Autoimmune liver disease (primary biliary cirrhosis)

Response to Liver Damage

• Hepatocytes are lost and fibrosis occurs, leading to scarring
• Eventually, hepatocytes are replaced by fibrosis, causing liver failure

Causes of Liver Failure

• Chronic liver damage
• Massive necrosis of hepatocytes

Consequences of Liver Failure

• 7 consequences:
  • Jaundice
  • Encephalopathy
  • Bleeding tendency
  • Portal hypertension, ascites, hepatomegaly, and arteriovenous shunts
  • Secondary renal failure
  • Anorexia, weight loss, and weakness
  • Pruritis

Hepatitis

• Hepatitis is a viral infection of the liver, leading to swelling and inflammation
• In chronic conditions, it can progress to cirrhosis and liver failure
• Caused by various viruses, each with different incubation times and transmission routes

Hepatitis A

• Acquired through contaminated food or water via the faeco-oral route
• Questions to ask if suspected:
  • Change in taste or smell?
  • Travel to endemic areas?
  • Consumption of raw shellfish?
• Incubation period: 2-6 weeks
• Symptoms: Jaundice
• Recovery time: 3 months (spontaneous recovery)
• Mortality rate: 0.2% (rarely any complications)
• Vaccine available: Yes

Hepatitis E

• Acquired through contaminated food or water via the faeco-oral route
• Incubation period: 4-6 weeks
• Most common in: India
• Mortality rate in pregnant women: 20%
• Spread: From animal reservoirs

Hepatitis B

• 6 diagrammatic features:
  • HBV DNA
  • Core protein
  • Polymerase
  • Lipid
  • Hep B surface Antigen
  • E antigen
• Life cycle:
  • Binds Sodium/Bile acid co-transporting peptide
  • Endocytosed, membranes fuse, core released
  • DNA travels to nucleus, and polymerase transcribes the RNA
  • The virus assembles in the cytoplasm via RNA to DNA reverse transcription
  • The virus is released
• Spread:
  • Vertically at birth or horizontally in families
  • In the UK, via sexual contact or through infected blood
  • Minute traces of body fluids can transmit infection
• Questions to ask if suspected:
  • Sexual practices
  • Anal receptive?
  • Prostitute?
  • Sexual transmitted diseases?
  • Multiple partners?
• 100 times more infectious than hepatitis C
• Transmission in healthcare: 30% of sharps injuries to unvaccinated healthcare workers
• Mucocutaneous exposure risk: 0.1%
• Saliva infectious through blood content
• Incubation period: 2-6 months
• Infectious individuals: All those with chronic hepatitis
• Ratio of carriers to being positive: 1:4
• Factor giving carriers a greater chance of being positive: Circulating e-antigen

Hepatitis B Infection

• 5 signs determining acute infection:
  • HBsAg levels increase and decline at 12 weeks
  • HBV DNA levels increase and decline at 12 weeks
  • HBeAg levels increase and decline at 12 weeks
  • These all decline at 12 weeks with acute infections
  • Anti-Hbs and Anti-HBo increase after acute infection (after 12 weeks) to provide lifelong immunity
• Sign determining chronic infection:
  • HBsAg and HBeAg increase and stay high

Hepatitis B Vaccination

• 3 injections into the deltoid muscle
• 6 months required for adequate protection
• Side effects: Mild and rare
• Vaccination need to be repeated: If the person is obese
• Protection: 95%

Hepatitis D

• Defective RNA virus
• Can only infect in the presence of HBsAg
• Therefore, can only be transmitted with hepatitis B
• Most common in: Middle East, Africa, and parts of South America
• Percentage of people with hepatitis B who have hepatitis D in the UK: 2%
• Mortality: High
• Protection: The hepatitis B vaccine

Hepatitis C

• Initial symptoms: Hidden initially
• Type of virus: RNA virus
• Incubation period: 9 weeks
• Percentage of people with acute hepatitis as opposed to clear infection: 15% acute hepatitis, 20% clear infection
• Why it's a severe infection: The virus mutates faster than the immune response can respond
• Transmission:
  • By blood
  • Needle sharing by IVDU or tattooing
  • Overseas blood transfusions
• Questions to ask if suspected:
  • Working area?
  • Surgeon in trauma unit?
  • Body piercing?
  • Tattoos?
  • Cocaine use?
  • Alcohol use; amount used?
  • Darker urine?
• Percentage of people with hepatitis C in the USA and worldwide: 2% in the USA, 3% worldwide
• Other virus commonly associated with hepatitis C: HIV
• Risk of transmission via a sharps injury: Lower than hepatitis B
• Vaccine availability: No vaccine available