Hepatitis Viridae Flashcards Preview

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Flashcards in Hepatitis Viridae Deck (38):
0

How many viruses that primarily infect the liver exist?

Six:
5 RNA--> Hep A,C,D,E,G
1 DNA--> HepB

1

How are Hep A and E transmitted?

By the fecal-oral route. The rest parenterally.

2

What hep viruses can cause acute hep?

All of them.

3

What hep viruses can cause chronic hep?

HepB,C,D

4

What is the time usually needed for jaundice to occur in acute hep?

One to two weeks.

5

Give a basic description of HAV.

1. Naked icosahedral capsid with a positive single-stranded RNA.
2. 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).

6

What is the incubation period of HAV?

About 15-40 days.

7

What is the morphology of HepA?

Picorna viridae
1. Positive single stranded RNA.
2. No envelope (naked)
3. Icosahedral capsid

8

How is HepA transmitted?

Fecal-oral.

9

What characterizes acute viral hepatitis caused by HAV?

1. Fever
2. Jaundice
3. Painful enlarged liver --> 1% develop fulminant hepatitis.
4. HepA never becomes chronic.

10

What is the serology in HepA?

1. Anti-HAV IgM --> Active disease.
2. Anti-HAV IgG --> Old, not active disease. Protected against repeated infection.

11

What is the morphology of HBV?

Hepadna viridae.
1. Double-stranded circular DNA.
2. Envelope
3. Icosahedral capsid
4. Dane particle (intact virus)
5. HBsAg (envelope, capsid proteins)
6. HBcAg
7. HBeAg

12

What does the Dane particle include?

1. Envelope
2. Capsid associated proteins
3. Capsid
4. Core (DNA + protein enzymes)

13

What includes the HBcAg?

1. Double stranded DNA
2. DNA polymerase enzyme
3. Capsid

14

What does dissociation of the Dane particle leaves?

HBsAg and HBcAg.

15

What is the HBeAg?

Soluble component of the core, which is a marker for active disease.

16

How is HBV transmitted?

1. Blood transfusion
2. Needle sticks
3. Sexual
4. Across the placenta

17

What can HBV cause?

1. Acute viral hepatitis
2. Fulminant hepatitis
3. Chronic hep (10%)
4. Coinfection with HDV.
5. Risk for cirrhosis and HCC.

18

What is the serology of HBV?

HBsAg --> Disease (acute or chronic).
Anti-HBsAg --> Immunity: provides protection against repeat infection.
IgM anti-HBcAg --> new infection.
IgG anti-HBcAg --> old infection.
HBeAg --> High infectivity
Anti-HBeAg --> Low infectivity

19

What is useful to keep in mind about HBV?

1. Only HepB carries a DNA polymerase enzyme within the virion.
2. Liver injury occurs from a cell-mediated immune system attack on HBV.

20

What is the morphology of HCV?

1. Propably a flavovirus
2. Single-stranded RNA
3. Enveloped icosahedral capsid

21

How is HCV transmitted?

Same way as HBV.

22

What can HCV cause?

Acute viral hep.
1. Up to 85% develop chronic hep.
2. 20% will develop cirrhosis.
3. Increased risk of developing primary HCC.

23

What is the serology of HCV?

Anti-HCV antibodies.

24

What is important to remember about HCV?

1. It is the leading cause for liver transplantation.2
2. Genotype 1 most common in US.

25

What is the morphology of the HDV?

1. Incomplete RNA virus - only infective with the help of HBV.
2. Helical nucleocapsid that requires the hepB envelope (HBsAg) to be infectious.

26

How is HDV transmitted?

Same way as HBV.

27

What can HDV cause as a coinfection?

Acute hep together with HBV.

28

What can HDV cause as a superinfection?

HDV infects patient with chronic HepB who cannot make Anti-HBsAg antibodies ---> Fulminant hep and cirrhosis.

29

Is serology helpful in HDV infection?

No, since detectable titers of IgM and IgG anti-HDV are not so high.

30

What is the morphology of HEV?

Hepeviridae family.
1. Single stranded RNA.
2. No envelope.

31

How is HepE transmitted?

Fecal-oral.

32

What can hepE cause?

Hepatitis like hepA.

33

What is important to remember about HEV?

Responsible for epidemics of hep in Asia. Very rare in the US.

34

What is the morphology of HGV?

The one of a flavivirus.

35

How is HGV transmitted?

Transfusion and needle sticks.

36

What can HGV cause?

It is not conclusively shown to cause liver disease.

37

What is interesting to remember about HGV?

Some studies have shown that co-infection with HGV might actually slow the progression of HIV disease. (!)