Viral Hepatitis Overview

Viral Hepatitis Overview

• Viral hepatitis is a viral infection of the liver.
• Hepatitis viruses A, B, C, D, and E exist.
• Hep A, B, and C are most relevant to dentistry.

Hepatitis A

• Caused by the hepatitis A virus.
• Spread via the faecal-oral route (contaminated food/drinks).
• Common in areas with poor sanitation.
• Symptoms typically resolve within a few months.
• No specific treatment; symptom relief is common.
• Prevention through vaccination, especially before travel to high-risk areas.

Hepatitis B

• Caused by the hepatitis B virus (HBV).
• Common worldwide.
• Spread through blood (infected person's blood).
• Vertical transmission (mother to child).
• Transmission through unprotected sex, shared needles, razors, & toothbrushes.
• 5% of infected individuals become chronic carriers.
• Can lead to cirrhosis and liver cancer.
• Can persist for years in children and cause liver damage.
• 90% of infected infants develop chronic hepatitis.

Hepatitis B - Body Fluid Concentration

• Low/undetectable: Urine, faeces, sweat, tears, breast milk.
• High: Blood, serum, wound exudates.
• Moderate: Semen, vaginal fluid, saliva.

Hepatitis B - Transmission

• Highly infectious, more so than HIV.
• Can survive outside the body for up to 7 days.
• Spread through blood contact.
• Not typically spread by casual contact (hugging, kissing).
• After a needlestick injury, seroconversion risk is higher in unvaccinated individuals compared to those who are vaccinated. (1 in 3 vs 1 in 300 for HIV).

Hepatitis B - Pathogenesis

• Incubation period: 45-180 days (average 60 days).
• Virus enters liver cells (hepatocytes).
• Immune response to viral antigens triggers the clinical syndrome.
• 5% become chronic carriers (high risk of hepatocellular carcinoma).
• Hepatitis B surface antibody likely provides lifelong immunity.

Hepatitis B - Symptoms

• May be asymptomatic.
• Symptoms (when present) appear 2-3 months after exposure.
• Flu-like symptoms, tiredness, fever, aches, loss of appetite, nausea, diarrhoea, gastric pain, and jaundice.
• Acute hepatitis B symptoms usually resolve in 1-3 months.
• Chronic hepatitis B may last 6+ months.
• Many people live with the virus unknowingly.

Hepatitis B - Diagnosis

• Blood testing (serological tests).
• Hep B antigens indicate infection.
• Hep B antibodies confirm recovery or immunity.
• Virus may persist at low levels after recovery.
• Reactivation is possible, especially in individuals with weakened immune systems.

Hepatitis B - Treatment

• Emergency care: Post-exposure treatment with Hep B vaccination & immunoglobulin.
• Acute Hepatitis B: Rest, analgesia (pain relief), symptom relief (e.g., nausea medication).
• Chronic Hepatitis B: Peginterferon alfa-2a (stimulates immune response), anti-viral medication (e.g., tenofovir or entecavir).

Hepatitis B - Prevention and Treatment Continued

• Prevention: Avoid unprotected sex, don't share needles, toothbrushes, or razors. Eat a healthy balanced diet & avoid alcohol.
• Chronic hepatitis B patients may need extensive lifestyle changes.

Hepatitis B - Prevention (Vaccination)

• Vaccination recommended for those at increased risk of HBV infection.
• 3 doses (0, 1, & 6 months).
• Immune response: 50% after 1 dose, 95% after 3 doses.
• Protection lasting >15 years. This depends on initial antibody response.

Hepatitis B - Prevention (Other)

• Hepatitis B immunoglobulin (HBIG): effective within 48 hours of exposure.
• Screening of blood donors & blood/body fluid precautions.

Hepatitis B - Remember!

• HBV carries high mortality risk.
• Healthcare professionals should be vaccinated.
• Treat all patients as possible HBV carriers (universal precautions).
• Always wear appropriate PPE (personal protective equipment).
• Prevent needlestick injuries and report them immediately.

Hepatitis C

• Single-stranded RNA virus.
• Pathogenesis, symptoms, and transmission routes similar to HBV, especially occupational transmission (needlestick injuries).
• No vaccine available against Hepatitis C.
• Chronic infections can cause cirrhosis, liver failure, and liver cancer.
• Treatment: Direct-acting anti-viral medications (8-12 weeks).
• Lifestyle changes (stop alcohol, healthy diet, exercise, stop smoking, don't share).

Hepatitis D

• Delta virus.
• Only infects those with HBV.
• Chronic D infections cause liver scarring (cirrhosis), and liver cancer.
• Spread by contact with bodily fluids.

Hepatitis E

• RNA virus.
• Transmitted by faecal-oral route, similar to Hepatitis A.
• Vaccination available.

Explore the essential facts about viral hepatitis, focusing on the types A, B, and C, especially in relation to dentistry. Understand the causes, transmission methods, symptoms, and preventive measures for these liver infections. This quiz provides valuable insights into the impact of hepatitis on public health and dental practice.