[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
What investigations are used for hepatitis B?
- Serological markers
- General liver investigations
- Tests for Hep C and HIV
- Screening for liver cancer
- Staging investigations
What are some general liver investigations?
- FBC
- Bilirubin
- Liver enzymes
- Clotting
- Ferritin
- Lipid profile
- Autoantibody screen
- Caeruloplasmin
What test can be used to screen for liver cancer?
- Ultrasonography
- Alpha-fetoprotein
What are some hepatitis B staging investigations?
- Transient elastography
- Liver biopsy
What can be used to determine a person’s hepatitis B infection status?
Serological markers
What are the serological markers looked at in hepatitis B?
- Surface antigen (HbsAg)
- Core antibody (HbcAb)
- Surface antibody (HbsAb)
What are the serological markers of an acute infection?
- HbsAg +ve
- HbcAb (IgM) +ve
- HbsAb +ve/-ve
What are the serological markers of a cleared hepatitis B infection?
- HbsAg -ve
- HbcAb (IgG) +ve
- HbsAb +ve
What are the serological markers of a chronic hepatitis B infection?
- HbsAg +ve
- HbcAb (IgG) +ve
- HbsAb -ve
What are the serological markers of a person vaccinated for hepatitis B?
- HbsAg -ve
- HbcAb -ve
- HbsAb +ve
What general advise is given to patients with hepatitis B?
- Avoid unprotected sex until non-infectious
- Give explanation of the condition and long-term health implications
- Advise not to give blood
- Avoid alcohol until liver enzymes normal
Where can acute hepatitis B be treated?
In primary care unless seriously ill
What are the main treatment options for acute hepatitis B?
Supportive management with fluids, anti-emetics and rest
When is anti-viral treatment indicated in hepatitis B?
Fulminant hepatitis
How is chronic hepatitis B cured?
There is no cure
How is chronic hepatitis B managed?
Through life-long anti-virals to suppress replication
Who may not require life-long anti-virals in chronic hepatitis B?
Those who are inactive carriers
When do inactive carriers of hepatitis B not require antiviral treatment?
- Low viral load
- Normal LFTs
- Mild fibrosis
What drug can be used to treat hepatitis B?
Peginterferon alfa-2a
What is the action of peginterferon alpha-2a?
Stimulates the immune system to attack the virus
What are the common side-effects of peginterferon alpha-2a?
Flu-like symptoms
What is the main method of preventing hepatitis B?
Vaccination
What is the hepatitis B vaccination?
A genetically engineered surface antigen
How many doses of hepatitis B vaccine are provided to give coverage?
3 + boosters if required
Who is the hepatitis B vaccine most effective in?
Younger people
What is defined as a protective response to the hepatitis B vaccine?
≥10mlU/ml of anti-HB antibodies in the serum
When is the hepatitis B vaccine routinely given?
To all babies at 8, 12, and 16 weeks
Who is hepatitis B vaccine given to if not received as a baby?
Those at risk of hepatitis B or complications
What are the potential complications of hepatitis B?
- Fulminant hepatic failure
- Cirrhosis
- Hepatocellular carcinoma
- Cryoglobulinaemia
- Membranous nephropathy
- Polyarteritis nodosa
What is the important public health consideration with hepatitis B?
It is a notifiable disease
What is meant by hepatitis B being a notifiable disease?
All suspected cases should be reported to the local Health Protection Team via notification form
Should a patient be told that the local health protection team is being notified of their hepatitis B?
Yes
