Viral Hepatitis Flashcards
Define hepatitis
Infection of the liver
Destruction of the hepatcytes - chronic inflammation, scarring, cirrhosis
Can caused by alcohol, autoimmune conditions,
What can cause “collateral” liver damage
Many systemic viruses cause “collateral”
liver damage
– Eg EBV, CMV, VZV
What are hepatitis viruses
Hepatitis viruses
– Replication specifically in hepatocytes
(hepatotropic)
– Destruction of hepatocytes
Describe the transmission and incubation. Hey b and c
B - blood/vertical/sex - 6wks-6mth
C - blood/sex - 6-12wks
Both may end up with chronic infection
Describe the viral structure of hepatitis
See slide
Describe the production/excretion of bilirubin
See slide
What are types of jaundice
Can be prehepatic, hepatic or post hepatic
What causes prehepatic jaundice
Haemolysis- unconjugated bilirubin to build up
What causes hepatic jaundice
Viral hepatitis, drugs ,alcoholic hepatitis, cirrhosis,
What causes pothepatic jaundice
Carcinoma of bile duct, pancreas head, ampulla, biliary stricture,
What are some liver function tests
• Bilirubin • Liver transaminases – Alanine transaminase (ALT) - produced when hepatocytes are damaged – Aspartate aminotransferase (AST) – Hepatocyte damage / cellular integrity • Alkaline phosphatase (ALP) – Biliary tract cell damage / cholestasis
• Albumin - a protein synthesises in liver
• Tests of coagulation
– clotting factors are synthesised in liver
– INR (International Normalised Ratio)
– Prothrombin time (PT)
How is hepatitis transmitted
Transmission-who is at risk? • Vertical transmission (75% cases globally) – Perinatal transmission in pts from highly endemic areas • Sexual contact • People who inject drugs • Close household contacts – significant blood exposure • HCW via needlestick injuries
What are they symptoms of acute hep b
- Jaundice
- Fatigue
- Abdominal pain
- Anorexia/Nausea/Vomiting
- Arthralgia
Hwo long is hepatitis b smth
• Incubation 6wks - 6 months.
• AST/ALT in 1000s
• Up to 50% - no/vague symptoms
• Clear infection within 6 months
• <1% - fulminant hepatic failure
• Becomes chronic in <10% if infected as adult
– 90% if infected in infancy (Asia/China)
What is the first antigen detectable in hepatitis b
Surface antigens - definitely have hepatitis - within 6/52; rise in ALT/DNA
Followed by e-antigen - highly infection
What is the first antibody to appear
Core antibody IGM
Followed by e-antibody - heralds disappearance of e-antigen + infectivety
What is the last antibody to appear
Surface antibody - clearance of virus/recovery
Core antibody persists for life
Define chronic hepatitis b infection
- Persistence of HBsAg after 6 months - still infected
* 25% chronic infection leads to cirrhosis and ~5% will develop hepatocellular carcinoma.
What is the treatment for chronic hepatits b
• NO CURE – integrates into host genome
• Life-long anti-virals to suppress viral replication
• Not required for everyone (e.g. “inactive” carrier)
– Low VL / normal LFTs / no liver damage
Important to keep monitoring lifelong
Describe hep b vaccination
• Genetically engineered surface antigen • 3 doses + boosters if required • Effective in most people • Produces surface antibody response – >10 adequate – >100 long-term protection
Who is at risk of hepatitis c
• People who inject drugs (“Intravenous drug
users”) >90% of those with Hep C in UK
- IV Heroin / crack / metamphetamines - Crack or heroin smokers
• Sexual contact (<1% but higher if HIV co- infected)
• Infants born to HCV positive mothers (<5%)
• Blood transfusion prior to 1991.
• Needlestick injuries to HCW etc.
Hoe does hepatitis c progress
~80% become chronically infected
• Of these some will develop chronic liver disease/cirrhosis. Resulting in:
– Decompensated liver disease
– Hepatocellular carcinoma (primary liver cancer)
– Transplant
– Death
What are the symptoms of hep c
80% have no symptoms (acute or chronic)
• 20% have vague symptoms
–Fatigue –Anorexia –Nausea –Abdominal pain (RUQ)
What are the blood tests for hep c
• Serology – anti-Hep C antibody only
• Remains positive life longer, even after clearance / cure
– Not protective, can get re-infected
• Viral PCR
– If positive, confirms on-going / chronic infection - this will confirm if currently infected or not
