S8) Blood Borne Viruses – Hepatitis Flashcards
What is hepatitis?
Hepatitis is the inflammation of the liver due to cell injury or viruses (hepatotropic) which can cause collateral liver damage e.g. EBV, CMV, VZV
Outline Hepatitis B and C in terms of transmission, incubation and affirmation of chronic illness
Outine the viral structure of different types of hepatitis
- Hepatitis B: dsDNA, enveloped
- Hepatitis C: ssRNA, positive, enveloped, icosahedral
Outline the production and excretion of bilirubin
Identify the different types of jaundice and their causes
- Prehepatic – caused by haemolysis
- Intrahepatic – caused by viral hepatitis, drugs, alcohol hepatitis, cirrhosis
- Extrahepatic – caused by common duct stones and carcinoma
Identify some liver function tests (LFTs)
- Bilirubin
- Albumin
- ALT & AST
- Alkaline phosphatase (ALP)
- Coagulation tests – INR & PT
How can Hepatitis B be transmitted?
- Vertical transmission
- Sexual contact
- Contaminated needles (IVDU, HCW)
What are the symptoms of acute Hep B?
- Jaundice
- Fatigue
- Abdominal pain
- Anorexia / nausea / vomiting
- Arthralgia
What are the microbiological findings of Acute Hep B?
AST/ALT in 1000s
Describe the complications of Acute Hep B
- Up to 50% – no/vague symptoms & clear infection within 6 months
- <1% – fulminant hepatic failure
- <10% – becomes chronic (if adult)
- Up to 90% – becomes chronic (if infant)
Outline the 6 steps in Hepatitis B serology
⇒ Surface antigen, within 6 weeks (HBsAg)
⇒ Highly infectious e-antigen (HBeAg)
⇒ Core antibody appears first (IgM)
⇒ e-antibody appears, less infectious now (HBeAb)
⇒ Surface antibody appears last, clears virus (HBsAb)
⇒ Core antibody persists for life (IgG)
What is a chronic Hep B infection and what are its consequences?
A chronic Hep B infection is the persistence of HBsAg after 6 months:
- 25% chronic infection leads to cirrhosis
- ~5% will develop hepatocellular carcinoma
What is the treatment for chronic Hepatitis B?
- NO CURE – integrates into host genome
- Life-long anti-virals required to suppress viral replication
- Not required for everyone e.g. “inactive” carrier (Low VL / normal LFTs / no liver damage)
Describe the composition and effective response of the Hepatitis B vaccination
- The vaccination consists of a genetically engineered surface antigen (3 doses + boosters if required)
- Produces surface antibody response:
I. >10 adequate
II. >100 long-term protection
What’s the status (HBsAg, HBsAb, HBcAb) for Hepatitis B in terms of:
- Acute infection
- Cleared infection
- Chronic infection
- Vaccinated