Viral Hepatitis Flashcards
what are the 5 hepatitis viruses
Hep A Hep B Hep C Hep D Hep E
Transmission of Hep A
grows in liver excreted down via bile ducts into gut spreads faecal-orally facilitated by poor hygiene and overcrowding Some clusters in gay men and IVDUs
Clinical presentation of Hep A
Acute hepatitis - no chronic infection
Lasts days/weeks
Peak incidence of symptomatic disease is in older children/young adults
if infected in early childhood there are no symptoms
Investigations for Hep A
Lab confirmation
clotted blood for serology
looking for Hep A IgM
How to reduce HepA outbreaks
Improve hygiene
reduce overcrowding
vaccine prophylaxis - given to those at greater risk, those travelling etc, gay men, and injecting drug users
Which hepatitis viruses are common in UK
Hep E
More common in tropics
More common than hep A in UK
How does Hep E present
Like Hep A
How is Hep E transmitted
faecal orally
What animal does hep E come from
Pigs
zoonoses
What Hep E genotypes are associated with severe disease in pregnant women
tropical genotypes
Who gets chronic Hep E infections
those who are immunocompromised
What virus do those with Hep D have
Hepatitis B virus
Makes the Hep B virus worse
Parasite of a parasite
rare in Scotland
How is Hepatitis B transmitted
Sex
Mother to child at delivery
Blood to blood contact (sharing needles)
Who gets chronic hep B infections
those who have first exposure in childhood
Who is at greater risk in the of getting Hep B
Those born in areas of high prevalence
Those with multiple sexual partners
People who inject drugs
Children of infected mothers
Which hepatitis vaccine is given in early childhood in UK
Hep B
Investigations for Hep B
Lab confirmation
Hep B surface antigen (HBsAG) present in blood of all infectious individuals
Hep B virus DNA also present in highly infectious individuals
Hep B DNA tests also used to predict risk of chronic liver disease
Hep B IgM present in those recently infected
Hep B antibodies present in blood after infection
What is the definition of a chronic Hep B infection
HBsAG in blood for more than 6 months
How can you control Hep B
Minimise exposure -safe blood -safe sex -safe needle exchange -prevention of needle sticks -screening of pregnant women Give immunisation -all children born since 2007 vaccinated -vaccination of all at risk older children and adults Post-exposure prophylaxis -vaccine -plus HBIG (hyperimmune Hep B immuonglobin)
Hepatitis C has a vaccine true/false
False
no vaccine available as it is a diverse collection of viruses
How is Hep C transmitted
same as Hep B
sex
blood
mother to child
What happens when injected with Hep A
Infection
- asymptomatic
- acute hepatitis - can lead to chronic infection
- acute liver failure (rare) - causes death
What happens in chronic infection of Hep A
- chronic hepatitis
- cirrhosis
- chronic liver failure - death
- OR cancer - death
Can Hep B be spontaneously cured
YES even after many years of infection
Can hep C be spontaneously cured
NO
How long does it take from infection to cirrhosis
> 20 years
patient usually asymptomatic
Time from infection to hepatocellular carcinoma
> 30 years
patient usually asymptomatic
What happens after a hep C infection
Most people asymptomatic which leads to resolution (25%) or chronic infection (75%)
What happens after Hep B infection
mostly asymptomatic
mainly leads to resolution
less than 5% get chronic infection
Which hepatitis is ‘mild’
Hep E
Tests for Hep C
Antibody test
If positive either past or active infection of Hep C
If positive test for Hep C RNA by PCR - positive is active infection
How to control hepatitis C
Minimise exposure
No vaccine
How to manage acute viral hepatitis
Symptomatic
No antivirals given
Monitor for encephalopathy
Monitor for resolution
Notify public health
Immunise contacts if a vaccine (hep A & B)
Test and vaccinate against other infections
Management of chronic viral hepatitis
Antivirals
-12 for C
-6 for B
-Genotype of hep C us important in deciding which antiviral
Vaccination
-against other hep
-influenza and pneumococcal in cirrhotic
Infection control
Reduce alcohol intake
Hepatocellular carcinoma awareness/screening
-AFP
Issues with antiviral treatment of chronic viral hepatitis
For hep C must know genotype of virus
For hep B must know hep B DNA and surface antigen present
Prioritise patients at greatest risk of complications
-evidence of inflammation/fibrosis
-do non-invasive tests of fibrosis (fbroscan)
-biochem evidence of inflammation (increase ALT)
Higher HBV DNA starting load the lower the risk of developing cancer true/false
false
higher risk of developing cancer
What is interferon alfa and what hep is it still used for
Used for B Protein produced by human cells- part of innate response Given by injection as peg interferon Complex mode of action - immune adjacent - helps along the immune system Many side effects -flu like symptoms -thyroid disease -autoimmune disease -psychiatric disease
Therapy for chronic Hep B
option 1 - suppressive antiviral - safer but suppression not cure
option 2 - peg interferon alone - cure but bad side effects
What are the aims/benefits of chronic hep B therapy
reduction in HBV DNA (suppression)
loss of HBeAg (more suppression)
loss of HBsAg(cure)
aims/benefits of chronic Hep C therapy
Loss of HCV RNA in blood sustained to 6 months after end of therapy
virological cure
Sustained virological response
Benchmark aim for Hep C therapy
> 90% sustained virological response
How long to you treat chronic hep C to cure it
12 weeks
