Liver disease Hepatitis

Study Notes

Caused by the hepatitis B virus
Common worldwide infection
Spreads through blood, from infected mothers to babies, unprotected sex, sharing needles, razors, or toothbrushes
5% develop chronic hepatitis B
Some develop cirrhosis or liver cancer
Can persist in children, causing significant liver damage
90% of infected babies develop chronic hepatitis
Vaccination for all healthcare workers, added to child immunisation list since 2017
High concentration in blood, serum, and wound exudates
Moderate concentration in semen, vaginal fluid, saliva
Low/undetectable concentration in urine, faeces, sweat, tears, breast milk
Very infectious, can survive outside the human body for up to 7 days
Not spread by hugging, kissing, or sharing eating utensils

Incubation period: 45 to 180 days (average 60 days)
Virus enters hepatocytes via the bloodstream
Immune response to viral antigens on hepatocyte surfaces is responsible for clinical syndrome
5% become chronic carriers, at higher risk of hepatocellular carcinoma
Hepatitis B surface antibody likely provides life-long immunity

May be asymptomatic
Symptoms (if present) appear 2-3 months post-exposure
Symptoms can include: tiredness, fever, general aches, loss of appetite, nausea, diarrhea, stomach pain, and jaundice
Acute Hepatitis B symptoms usually resolve within 1-3 months
Chronic Hepatitis B can last for 6 months or longer

Emergency treatment following exposure: Hep B vaccination & immunoglobulin
Acute Hepatitis B: Rest, analgesia, and symptom relief (e.g., metoclopramide for nausea)
Chronic Hepatitis B: Peginterferon alfa-2a (stimulates immune system to attack virus) and antiviral medications (e.g., tenofovir, entecavir)

Vaccination for those at increased risk of HBV infection (3 doses: month 0, 1, 6)
Good immune response (50% after 1 dose, 95% after 3 doses) with lasting protection (>15 years) depending on initial antibody response
Hepatitis B immunoglobulin (to protect exposed people) within 48 hours post-exposure
Screening of blood donors, blood and body fluid precautions

Single-stranded RNA virus
Similar pathogenesis, symptoms, and transmission routes as hepatitis B
Occupational transmission risk, including needlestick injury and blood splash to eye
No vaccine exists
Long-term complications can include cirrhosis, liver failure, and liver cancer
Treated with direct-acting antiviral medications (e.g., ribavirin, simeprevir, sofosbuvir) for 8-12 weeks

Hepatitis D: Delta virus; only infects those with Hepatitis B; chronic infections can lead to cirrhosis, and liver cancer; spread via bodily fluids, including IV drug users;. Vaccine available
Hepatitis E: RNA virus; similar transmission to Hepatitis A (facaelo-oral); no vaccine

Hepatitis B carriers pose a definite mortality risk and should be treated as potential disease carriers
Healthcare professionals should be immunized and adhere to universal precautions
Always wear appropriate personal protective equipment (PPE) to prevent saliva from entering the eye.
Always avoid needlestick injuries, and report them immediately to the correct authorities if they occur