Viral Hepatitis Flashcards
What is the main clinical maifestation of hepatitis viruses
Cause liver disease
Why has there been a decline of acute Hep A
Due to vaccination and better housing
Who is most commonly diagnosed with Hep B
Ethnic minorities who acquired Hep B mostly outside of the UK
What has caused the rise in Hep E in recent years
A mix of cases acquired outside the Uk and cases acquired within the UK
How is Hep A transmitted?
Faecal-oral
Poor hygiene / overcrowding
What are the common clinical presentations of Hep A
Usually asymptomatic
In what population is there a peak incidence of symptomatic disease
Older children / young adults
How is Hep A confirmed
Lab confirmation
Clotted blood for serology - yellow top bottle
How effective is the vaccine prophylaxis
Good - gives long term protection but needs 10 days to take effect
How is Hep A controlled?
Through good hygiene - infected food handlers are excluded from the workplace
Where is Hep E most common
In the tropics
What is more common in the UK Hep A or Hep E
Now Hep E
How is Hep E transmitted
Faecal-oral
What other animals can have Hep E
Pigs, deer, rabbits
How can some humans become infected with Hep E?
If they are immunocompromised
When is Hep D found
In association with Hep B
What is the effect of Hep D
It exacerbates Hep B
How is Hep B transmitted? (3 ways)
Sex
Mother to child
Blood (IV drug users)
What happens to the risk of chronic infection with increasing age at exposure
Decreases
What happens to the risk of acute hepatitis as age increases at exposure
Increases
Where is there a high prevalence of Hep B and why?
Canada, Alaska and Greenland
Due to their indigenous communities
How is Hep B confirmed
Lab - surface antigen (HBsAg) present in blood
What is also likely to be present in recently infected cases
Hep B IgM
How can we acquire immunity of Hep B
Vaccine or past infection
Describe the relationship between an indivual chronically infected with their infection
Dynamic - constantly changing - 1 treatment may not be applicable 1 day and would be the next
How can we control the spread of Hep B
Minimise exposure safe blood, safe sex needle exchange prevent needlestick injuries Screening pregnant women
What would happen to the baby if the mother was Hep B positive during pregnancy
Given a vaccine at birth to prevent mother to child transmission
What are the two pre-exposure vaccination strategies
Vaccination of at risk people
Vaccination of all children / adolescents
How is Hep C transmitted
Similar to Hep B
Mother to child
Blood
Less often through sex
What are the precautions for Hep C
Minimise exposure safe blood, safe sex needle exchange prevent needlestick injuries Screening pregnant women
How is hep C controlled
There is no vaccine
Minimise the exposure
What defines chronicc
six months of infection
What happens once there is a confirmed diagnosis for Hep C
Spontaneous cure is not seen
What is the time it takes for the infection to cause cirrhosis
Typically more than 20 years
How long does it typically take for Hepatitis C to cause heaptocellular carcinoma
More than 30 years
What is the management of acute viral hepatitis
No antivirals
Monitor for encephalopathy
Monitor for resolution of Hep B, C or E if immunocompromised
Notify public health
immunisation of contacts
test for other infections if at risk
Vaccinate against other infections i at risk
What is the management of chronic viral hepatitis
Antibrials Vaccination INfection control Decrease alcohol consumption Hepatocellular carcinoma awareness / screening
What are the 2 most commonly used therapies in HBV?
Adefovir
Entecavir
Who do we treat for viral hepatitis?
Chronic infection
Those at risk of complications
Those who are fit for treatment
When is it best to treat viral hepatitis?
Before complications arise
When there is evidence of inflammation - advanced fibrosis
When the patient is ready
When it is a clinical priority
What is interferon alfa
A human protein and part of the immune response to viral infection
How is interferon alfa made
Through genetic engineering
How is interferon alfa delivered
Given by injection
What are 3 side effects of interferon alfa
Flu like symptoms
Autoimmune disease
Psychosis
What are the 2 options for therapy of chronic hepatitis B
Peginterferon alone
Suppressive antiviral drug
What are the advantages of using Peginterferon
Sustained cure possible from a few months of therapy
What are the disadvantages of Peginterferon
Side effects
Injections
Only some benefit
What are the advantages of Suppressive antiviral drugs
Safer
Larger range available
What are the disadvantages of suppressive antiviral drugs
suppression not cure
resistance can develop
What are some of the aims/ benefits of chronic hep B therapy
Improved liver biochemistry Improved histopathology Reduced infectivity Reduced progression to cirrhosis and primary hepatocellular carccinoma Reduced mortality
What are some of the aims/ benefits of chronic Hep C therapy
Improved liver biochemistry improved histopathology reduced infectivity reduced incidence of primary liver cancer reduced mortality
