Hepatitis Flashcards
How is Hep A transmitted?
Faecal-oral spread
Poor hygiene/overcrowding
Some cases imported
Some clusters - gay men and People Who Inject Drugs
When is Hep A most prevelant? Can it be acute or chronic?
Peak incidence of symptomatic disease in older children/young adults
Can be acute - not chronic
What investigations can be done for Hep A?
Laboratory confirmation of acute infection
- Clotted blood for serology (gold top vacutainer)
- Hepatitis A IgM
What control measures can be taken to prevent Hep A?
Hygiene
Vaccine prophylaxis - gay and IV drug users
What are the characteristics of Hep E?
More common in tropics (person to person transmission)
Has become more common than Hep A in UK
Faecal-oral transmission like Hep A in tropics
Cases acquired in UK are thought to be zoonoses (genotype 3)
Tropical genotypes associated with severe disease in pregnant women
When does chronic Hep E come about?
immunocomprimised
What are the characteristics of Hep D?
Only found with Hepatitis B virus
Exacerbates Hepatitis B virus infection
Parasite of a parasite
Co-infection or superinfection
How is Hep B transmitted?
Sex - multiple partners
Mother to child
Blood - iv drugs, tattoos, bad transfusions
How is Hep B investigated?
Hepatitis B surface antigen (HBsAg) present in blood of all infectious individuals
- present for more than 6 months in chronic infection
- Hepatitis B e antigen (HBeAg) usually also present in highly infectious individuals
- Hep B virus DNA always also present in high titre (amount) in highly infectious individuals
- Hep B DNA tests also used to predict risk of chronic liver disease and monitor therapy
Hep B IgM most likely to be present in recently infected cases
Anti-HBs present in immunity (i.e. have cleared the antigen)
How can Hep B be prevented?
Minimise exposure: safe blood, safe sex, needle exchange, prevention of needlesticks, screening of pregnant women
Two pre-exposure vaccination strategies in use
- vaccination of all children born since 1st August 2017
- vaccination of at risk older children and adults
Post-exposure prophylaxis
- vaccine
- plus HBIG (hyperimmune Hep B immunoglobulin)
Screen pregnant women so that infected women can have their babies vaccinated at birth to prevent mother to child transmission
How is Hep C transmitted?
Sex
Blood
Mother to baby
What defines a chronic infection
6 months
What can Hep B and Hep C infection cause?
cirrhosis - 20 years
hepatocellular carcinoma - 30 years
There can be a spontaneous cure in Hep B or Hep C?
Hep B
What is the management of acue viral hepatitis?
Symptomatic
No antivirals given
Monitor for encephalopathy
Monitor for resolution of Hep B or Hep C, or Hep E if immunocompromised