Hepatitis Viridae Flashcards
How are Hep A and E transmitted?
By the fecal-oral route. The rest parenterally.
How many viruses that primarily infect the liver exist?
Six:
5 RNA–> Hep A,C,D,E,G
1 DNA–> HepB
What hep viruses can cause acute hep?
All of them.
What hep viruses can cause chronic hep?
HepB,C,D
What is the time usually needed for jaundice to occur in acute hep?
One to two weeks.
Give a basic description of HAV.
- Naked icosahedral capsid with a positive single-stranded RNA.
- It is in the family Picornaviridae and as it is the case with most of this family it is transmitted by the fecal to oral route (HAV = Anus).
What is the incubation period of HAV?
About 15-40 days.
What is the morphology of HepA?
Picorna viridae
- Positive single stranded RNA.
- No envelope (naked)
- Icosahedral capsid
How is HepA transmitted?
Fecal-oral.
What characterizes acute viral hepatitis caused by HAV?
- Fever
- Jaundice
- Painful enlarged liver –> 1% develop fulminant hepatitis.
- HepA never becomes chronic.
What is the serology in HepA?
- Anti-HAV IgM –> Active disease.
2. Anti-HAV IgG –> Old, not active disease. Protected against repeated infection.
What is the morphology of HBV?
Hepadna viridae.
- Double-stranded circular DNA.
- Envelope
- Icosahedral capsid
- Dane particle (intact virus)
- HBsAg (envelope, capsid proteins)
- HBcAg
- HBeAg
What does the Dane particle include?
- Envelope
- Capsid associated proteins
- Capsid
- Core (DNA + protein enzymes)
What includes the HBcAg?
- Double stranded DNA
- DNA polymerase enzyme
- Capsid
What does dissociation of the Dane particle leaves?
HBsAg and HBcAg.