L11: Viral Hepatitis Flashcards
(46 cards)
What major organ experiences complications as a result of hepatitis infections?
The Liver :D
Which system is the liver primarily a part of?
Biliary system - creates bile and filters harmful substances from the blood
Certain enzymes can assess liver function. WIll higher or lower levels of these enzymes (ALT, AST and GGTP) indicate acute liver injury?
Higher
What is hepatitis typically characterised by?
- Jaundice
- Fever
- Liver enlargement
- Abdo pain
What is cirrhosis?
When scar tissue replaces healthy tissue of the liver and blocks blood flow through the organ –> no functioning hepatocytes (increases risk of hepatocellular carcinoma)
What is Hepatocellular carcinoma (HCC)?
A primary malignancy of the liver. Most cases are secondary to Hep B or C infection or cirrhosis most commonly due to alcoholism.
What are Kuppfer cells?
Specialised macrophages in the liver that remove foreign particles and destroy RBCs (usually big, white, nucleated cells on histopath.)
What makes severe hepatits different from mild hepatitis?
Severe hepatitis commonly manifests with fluid retention, altered mental status and bleeding in addition to symptoms of mild hepatits (malaise, jaundice and abdo pain)
What is the difference between acute and chronic hepatitis?
Acute = quick disease progression, symptoms last < 6 months Chronic = slow progression, symptoms last > 6 months (especially in B and C)
What causes jaundice?
Build up of bilirubin in the blood (produced when old cells break down) as a result of the body no longer being able to process it.
Hepatitis A - source, mode of transmission, chronic (Y/N), how is it prevented?
Source = faeces Transmission = feacal-oral Chronic? = No Prevention = Pre/post exposure immunisation
Hepatitis B - source, mode of transmission, chronic (Y/N), how is it prevented?
Source = blood/body-derived fluids Transmission = percutaneous, permucosal Chronic? = Yes Prevention = pre/post-exposure immunisation
Hepatitis C - source, mode of transmission, chronic (Y/N), how is it prevented?
Source = blood/body-derived fluids Transmission = percutaneous, permucosal Chronic? = Yes Prevention = blood donor screening, risk factor modification (don't share needles, etc.)
Hepatitis D - source, mode of transmission, chronic (Y/N), how is it prevented?
Source = blood/body-derived fluids Transmission = percutaneous, permucosal Chronic? = Yes Prevention = pre/post-exposure immunisation, risk factor modification
Hepatitis E - source, mode of transmission, chronic (Y/N), how is it prevented?
Source = Faeces Transmission = faecal-oral Chronic? = No Prevention = ensure drinking water is safe
How is Hep A similar to poliovirus?
- Humans are the only natural host
- Naked
- Both belong to Picornaviridae (different genera though)
- Vaccines are available for both
How does Hep A replication work?
gains entry via RM endocytosis, RNA uncoating occurs, 1 ORF, translated into a polyprotein and then self-cleaved by viral protease, (RNA replication occurs in viroplasms), packaged and exits via cell lysis **UTRs increase transmissability
What factors contribute most to HAV pathogenesis?
Resistant to low pH and heat because it is a non-enveloped virus
Why is ALT important in HAV infection?
It is a surrogate for liver damage
How is HAV diagnosed?
ELISA: - anti-HAV IgM - anti-HAV IgG (also good for detecting past infection) Direct detection - EM - RT-PCR
Is there a HAV vaccine? If so, what type of vaccine is it?
Yes! It is inactivated with Al(OH)3 adjuvant and 1x booster between 6 and 18 months depending on brand
***China uses a live attenuated vaccine (single dose)
Hep B fun facts:
- Family
- sense & type of nucleic acid
- Hosts
- Main cellular target
- Number of serotypes
- Any cool features?
- Family = Hepadnaviridae
- sense & type of nucleic acid = dsDNA (+ve strand incomplete)
- Hosts = humans and chimps
- Main cellular target = hepatocytes
- Number of serotypes = 8
- Any cool features? = involves RT (may be a protein primer for synthesis???)
How is HBV transmitted?
- blood
- bodily fluids
Name three risk factors for HBV.
Any of:
- children of mothers with HBV
- people who live in the same house as someone with HBV
- blood donation recipients
- IV drug use
- Unprotected sex
- people whose occupation involves handling blood