Viral Hepatitis Overview for Dentistry

Viral Hepatitis Overview

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

Hepatitis A

• Caused by the hepatitis A virus.
• Transmitted through the faecal-oral route (contaminated food/water).
• Common in areas with poor sanitation.
• Symptoms typically resolve within a few months.
• No specific treatment; supportive care for symptoms.
• Preventable through vaccination, particularly for travel to high-risk areas.

Hepatitis B

• Caused by the hepatitis B virus (HBV).
• A common infection worldwide.
• Transmitted through blood and body fluids (unprotected sex, contaminated needles, razors, etc.).
• Can be transmitted from infected pregnant women to their babies.
• Can persist for years in children and cause significant liver damage.
• 90% of infected babies develop chronic hepatitis.
• Vaccination is important for all healthcare workers, and since 2017, it's included in child immunisation programs.
• HBV concentration in body fluids varies; high in blood, serum, and wound exudates; moderate in semen, vaginal fluid, and saliva and low in urine, faeces, sweat, tears, and breast milk.
• Very infectious, surviving outside the body for up to 7 days.
• Not spread through casual contact (hugging, kissing, coughing, sharing utensils).
• After needlestick injury, the risk of HBV seroconversion is substantially higher than in HIV if not vaccinated.

Hepatitis B Pathogenesis

• Incubation period: 45 to 180 days, average 60.
• Virus enters liver cells (hepatocytes) through the bloodstream.
• Immune response to viral antigens is responsible for the clinical syndrome.
• 5% of infected people develop chronic HBV carriage, significantly increasing the risk of hepatocellular carcinoma.
• Antibody to Hepatitis B surface antigen (HBsAb) likely provides lifelong immunity.

Hepatitis B Symptoms

• Can be asymptomatic; many people don't show symptoms.
• Symptoms (if present) develop 2-3 months post exposure.
• Flu-like symptoms (fatigue, fever, aches, loss of appetite, nausea, diarrhea, stomach pain), jaundice.
• Acute infections typically resolve within 1-3 months.
• Chronic infections can last for 6 months or more.

Hepatitis B Diagnosis

• Blood tests (serological tests), measuring Hep B antigens (markers of infection) and antibodies to help determine infection status, recovery, and immunity.
• Virus can persist at low levels even after recovery and reactivation can occur, especially in people with suppressed immune systems.

Hepatitis B Treatment

• Emergency Treatment (post-exposure): Hepatitis B vaccination and Immunoglobulin.
• Acute Hepatitis B: Rest, pain relief, and symptom management.
• Chronic Hepatitis B: Medications aim to reduce viral load and prevent liver damage (e.g., peginterferon alfa-2a, tenofovir, entecavir).

Hepatitis B Treatment and Prevention Continued

• Avoid unprotected sex and use of shared/unsterilised needles, razors, toothbrushes, etc.
• Vaccination for partners exposed and/or at risk.
• Eat a balanced healthy diet and avoid alcohol.

Hepatitis C

• Single-stranded RNA virus.
• Similar pathogenesis, symptoms, and transmission routes as HBV.
• Occupations with high risk of transmission (needlestick injuries, blood splashes).
• No vaccine currently available.
• Chronic hepatitis C is treated with direct-acting antivirals for 8-12 weeks (e.g., ribavirin, simeprevir, sofosbuvir).
• Lifestyle changes (healthy diet, exercise, avoiding alcohol, smoking) may be necessary.

Hepatitis D and E

• Hepatitis D: Delta virus; only infects individuals already infected with HBV; can cause chronic infections, serious complications (liver scarring, cirrhosis, and cancer), and is transmitted through bodily fluids, and frequently seen in IV drug users.

• Hepatitis E: RNA virus; transmitted via the faecal-oral route, similar to Hepatitis A; vaccine available.

Prevention of Viral Hepatitis

• Vaccination is a key preventative measure.
• Vaccination programs for HBV for healthcare workers and at-risk individuals.
• Proper handling and disposal of contaminated needles and sharps.
• Screening of blood donations.
• Universal precautions (treat all patients as potential carriers, use appropriate Personal Protective Equipment).
• Hep. B immunoglobulin (to protect individuals recently exposed) can potentially be very effective if administered within 48 hours of infection.

This quiz covers the essential aspects of viral hepatitis, focusing particularly on Hepatitis A, B, and C, which are significant to dental health. Understand the transmission methods, symptoms, and the importance of vaccinations. This overview is crucial for healthcare professionals, especially in the dental field.