[4] Hepatitis B Flashcards
What is hepatitis B?
An infection of the liver caused by the hepatitis B virus (HBV)
What type of virus is HBV?
A double-stranded DNA virus which replicates by reverse transcriptase
How many people worldwide have hepatitis B?
Over 350 million
What proportion of the UK is thought to have hepatitis B?
1 in 350
How is hepatitis B transmitted?
Parenterally via infected blood or body fluids
What are the routes of transmission of HBV?
- Vaginal or anal intercourse
- Sharing needles
- Sharps injuries
- Vertical transmission
- Blood transfusion
What is the effect of the HBV?
Interferes with the functions of the liver by replicating in hepatocytes
What causes damage to the liver in hepatitis B?
Hosts immune response causing hepatocellular damage
What are the risk factors for hepatitis B?
- IV drug use
- Multiple sexual partners
- MSM
- Born in highly endemic region
- Household contact with EBV
- Infected with HIV or Hep C
- Dialysis
What are the two forms of hepatitis B infection?
- Acute infection
- Chronic infection
How can acute hepatitis B infection present?
- Can be asymptomatic
- Can have acute viral hepatitis
What are the features of acute viral hepatitis?
- General ill-health
- Loss of appetite
- Body aches
- Mild fever
- Dark urine
- Progressive jaundice
How long do the symptoms of acute viral hepatitis last?
A few weeks and then gradually improves
What can acute hepatitis occasionally lead to?
Fulminant hepatitis
What is the danger of fulminant hepatitis?
It can be fatal
What is chronic hepatitis B?
A spectrum of disease characterised by the presence of detectable hepatitis B surface antigen (HbsAg) in the blood for longer than 6 months
How can chronic hepatitis progress?
- Inactive
- Liver fibrosis
- Cirrhosis
- Hepatocellular carcinoma
How can chronic hepatitis B be classified?
- e antigen positive
- e antigen negative
What is the presence of hepatitis B e antigen associated with?
- Higher rates of viral replication
- Increased infectivity
What are the potential symptoms of chronic hepatitis B?
- Fatigue
- Anorexia
- RUQ pain