Viral hepatitis Flashcards
What are the 5 types of heatitis viruses?
A, B, C, D and E
How is hepatitis A spread?
Faecal-oral spread
Due to poor hygiene or overcrowding
Clusters in gay men and PWID
What is the clinical presentation of hepatitis A?
Acute hepatitis, no chronic infection
Peak incidence of symptomatic disease in older children/ young adults
How is hepatitis A diagnosed?
Lab confirmation of acute infection via the presence of hepatitis A IgM
How is hepatitis A controlled?
Good hygiene
Vaccine prophylaxis
Where is hepatitis E common?
In the tropics `
How is hepatitis E transmitted?
Faecal-oral transmission
Evidence of chronic infection in pigs
Cases in UK are though to be zoonosis
Who can get hepatitis D?
Only found with Hep B, it is a parasite of a parasite and exacerbated hep B infection. It is a co-infection or superinfection
How is Hep B transmitted?
Sex
Mother to child
Blood
When are chronic infections likely to occur in hep B?
If first exposure is in childhood
Who is at high risk in the UK for infection of Hep B virus?
People born in areas of high prevalance
Multiple sexual partners
PWID
Children of infected mothers
What does hepatitis B surface antigen (HBsAg) show?
Indicates a patient is infected and infectious. More than 6 months indicates a chronic infection
What does Hepatitis B e antigen (HBeAg) show?
Usually high in highly infectious individuals
What does Hep B virus DNA show?
Predicts prognosis and infectivity
What does hep B IgM show?
Recently infected - acute cases
What is present in people who are immune to hep b?
Anti-HBs
How is hepatitis B controlled?
Minimise exposure: safe blood, safe sex, needle exchange, prevention of needlesticks, screening of pregnant women
2 pre-exposure vaccination strategies
Post-exposure prohpylaxis - vaccine plus hyperimmune Hep B immunoglobulin
How is Hep C transmitted?
Similar to Hep B but no vaccine avaliable
What defines a chronic infection?
6 months of infection
How is hepatitis C diagnosed?
Test for antibody to hepatitic C virus, is it positive this indicates a pat or active infection and then need to test for Hep C viruse RNA via PCR
What does it mean if the hep C RNA is found via PCR?
Active infection
How is hepatitis C controlled?
No vaccine, minimise exposure
How is acute viral hepatitis managed?
No antiviral, monitor for encephalopathy and monitor for resolution
Notify public health
Immunisation of contacts if poss
Test for other infections
What are notifiable diseases?
Those that are vaccine preventable, and others that can cause outbreaks or public alarm or high mortality
What are the common antivirals used in HBV therapy?
Adefovir
Entecavir
How is chronic viral hepatitis managed?
Antivirals Vaccination Infection control No alcohol Hepatocellular carcinoma awareness
Who should be treated for chronic infection?
HCV RNA present
HBsAG and Hep B DNA present
When should hepatitis be treated?
Before complications
When evidence of inflammation
What are the adverse effects of peginterferon?
Flu like symptoms
Thyroid disease
Autoimmune disease
Psychiatric disease
What are the virological benefits of chronic hep B therapy?
Reduction in HBC DNA (suppression)
Loss of HBeAg
Loss of HBsAg (cure)
What are the other benefits (not virological) of hep B treatment?
Imrpoved liver biochemistry Improved histopathology Reduced infectivity Reduced progression to cirrhosis and primary HCC Reduced mortality
What are the principles of HCV therapy?
Genotype of virus and viral load
Genotype of patients interferon response genes
Stage of disease
Past treatment experience
