MI: Viral Hepatitis Flashcards
How is hepatitis A spread?
Faecal-oral
What is the incubation period for hepatitis A?
2-6 weeks
Describe the natural history of hepatitis A infection.
- 2-6 weeks after the infection you will develop hepatitis (transaminitis)
- This will be accompanied by a rise in IgM
- A more gradual rise in IgG will follow
NOTE: hepatitis A infection is often subclinical
What is the diagnostic test for hepatitis A?
Anti-hepatitis A IgM
Which antibodies will be present if someone has received a hepatitis A vaccine?
High IgM and high IgG but NO transaminitis
How is hepatitis B transmitted?
- Sexually transmitted
- Blood products
- Mother-to-baby (e antigen is the biggest predictor)
What is the incubation period of hepatitis B?
2-6 months
What is the risk of chronic infection in adults and babies?
- 5-10% in adults
- 95% in babies
Describe the molecular organisation of hepatitis B virus.
DNA virus with four overlapping reading frames (core, X, polymerase and surface antigen)
NOTE: as they overlap, a mutation in one reading frame could affect others
Why do some antiretrovirals work on hepatitis B?
HBV uses reverse transcriptase to replicate
Where is the hepatitis e antigen found?
Pre-core part of the core reading frame
It’s a marker of active replication
What serological feature is suggestive of recent HBV infection?
Anti-HBV IgM antibodies
What serological feature is suggestive of chronic HBV infection?
Prolonged presence of HBsAg (more than 6 months)
What are some possible consequences of HBV infection?
- Hepatocellular carcinoma
- Cirrhosis
List the HBV disease stages.
- Immune tolerant
- Immune reactive
- Inactive HBV carrier state
- HBeAg negative chronic HBV
What is a strong indicator of risk of cirrhosis in people with hepatitis B infection?
HBV DNA level (copies/mL)
List some treatment options for chronic HBV.
- Interferon alpha
- Lamivudine
- Tenofovir
- Entecavir
- Emtricitabine
Which of these treatments should not be used in liver transplant patients?
Interferon alpha
When do you NOT give Hep B immunoglobulin to babies born to mothers with Hep B
If the mother has anti-HBe (this confers protection to the baby, but you still give the accelerated vaccine)
Which patient populations are particularly at risk of hepatitis C virus infection?
- MSM
- IVDU
Which phylogenetic family is HCV a part of?
Flaviviridae
What components constitute the viral RNA genome of hepatitis C?
- Core
- Envelope
- Non-structural components
What class of drugs are most antivirals used for hepatitis C?
- Protease inhibitors
- Inhibitors of non-structural components
What is the incubation period of HCV?
6-8 weeks