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
Outline the serological changes that take place following HCV infection.
Anti-HCV antibodies develop after the acute infection has resolved (i.e. ALT has returned to normal)
How is HCV treated?
Early treatment with peginterferon alfa
NOTE: peginterferon alfa 2b is interferon alpha with polyethelene glycol attached which improved its pharmacokinetics and turns it into a depot preparation
How is the response to treatment with peginterferon-alfa assessed in HCV infection?
Sustained viral response (SVR12) - no HCV RNA 12 weeks after stopping treatment
What is the main difference in the treatment of genotype 1 and non-genotype 1 HCV?
- Genotype 1 - high-dose long-lasting ribavirin is required for high cure rates
- Non-genotype 1 - ribavirin does NOT increase cure rates
What is a key feature about hepatitis D virus?
Requires the presence of hepatitis B to replicate within the host
What is the difference between hepatitis D co-infection and superinfection?
Co-infection:
- This happens when you are inoculated with HBV and HDV at the same time (e.g. sharing a needle with someone infected by both viruses)
- Anti-HDV IgM will rise after inoculation causing hepatitis
Superinfection:
- This happens when someone with chronic hepatitis B infection is inoculated by HDV
- This is more severe than coinfection
- Patients can develop cirrhosis within 2-3 years
Which phylogenetic family is heaptitis E a part of?
Herpeviridae
How is hepatitis E transmitted?
Faecal-oral
What are the genotypes of hepatitis E?
- 1 + 2 = human
- 3 + 4 = animals (mainly pigs)
NOTE: there is very little person-to-person transmission
Which patient group has a high mortality if infected by hepatitis E?
Pregnant women
NOTE: mainly associated with genotype 1
What is the incubation period of hepatitis E?
3 - 8 weeks
List some rare complications of hepatitis E.
- CNS disease (e.g. Bell’s palsy)
- Chronic infection
Outline the treatment of hepatitis E.
- Supportive
- Ribavirin
Outline the serological changes that take place in hepatitis E infection.
- Acute infection is accompanied by a rise in IgM anti-HEV antibody
- Rarely you can get persistently high levels of HEV RNA
NOTE: it generally responds well to ribavirin
What is hepatitis G?
- Pegivirus
- Simian virus
- May cause higher CD4 counts in HIV-positive patients
