Hepetitis Virus

Question 1

Hep A

Answer 1

Family: Picornaviridae
Genome: (+) ssRNA
Nonenveloped 
Transmission: fecal/oral, sexual, parenteral
Acute

Question 2

Hep B

Answer 2

Family: Hepadniviridae
Genome: Circular dsDNA (smallest genome of human viruses)
Enveloped
Transmission: sexual, vertical, parenteral
Chronic
**has reverse transcriptase b/c it goes through a DNA intermediate (cccDNA)

Question 3

Hep C

Answer 3

Family: Flaviviridae
Genome: (+) ssRNA
Enveloped
Transmission: sexual, vertical, parenteral
Chronic

Question 4

Hep Delta

Answer 4

Family: Deltaviridae
Genome: (-) ssRNA
Enveloped
Transmission: sexual, vertical, parenteral
Rare in US

Question 5

Hep E

Answer 5

Family: Calciviridae
Genome: (+) ssRNA
Nonenveloped
Transmission: fecal/oral, sexual, parenteral
Rare in US

Question 6

What is the incubation period, symptoms, recovery time, and prevention modes of Hep B

Answer 6

Incubation: 30-180 days
Symptoms: malase, anorexia, vomiting, fatigue, cough, serum-like sickness, jaundice, yellowing of the eyes
Recovery: ~ 3 - 4 months after onset of jaundice
- 5% become chronic. These people have sporadic episodes of hepatitis and cirrhosis of the liver, and leads to an increased risk for hepatocellular carcinoma (HCC)
- long term sequelae
Prevention: vaccination available (1st recombinant vaccine approved for use)
- requires multiple inoculations, and is not effective against chronic cases
- chronic cases are fought with interferon-a therapy, and/or nucleoside analogs: adefoir, lamivudine, tenofovir

Question 7

Describe Hep Delta.

Answer 7

Incubation:60-180 days
Hep Delta is a subviral agent (cannot infect by itself, it needs another virus)
- Requires Hep B virus in order to infect
RNA genome encodes a single protein

Question 8

Describe Hep C

Answer 8

Incubation: 60-120 days
Genome is (+) ssRNA so it replicates in the cytoplasm.
- passed into cytoplasm through receptor mediated enocytosis. The (+) ssRNA is excreted from the endosome into the cytoplasm where it serves as the template for translation.
- exits cell through budding
- ~ 80% chronic which can cause extra hepatic disease (mixed cryglobulinemia - virus infects other tissues and causes cell damage and death in those areas due to immune response)
No vaccine
- interferon-a treatment can help reduce chances for chronic infection and long term sequelae

Question 9

Describe Hep A

Answer 9

Incubation: 15-40 days
Genome is (+) ssRNA so it replicates in the cytoplasm. Predominately a fecal/oral infection
Symptoms: malaise, anorexia, vomiting, jaundice, painful diarrhea
- more prominent in children
Recovery: ~ 8 weeks after infection
Prevention: Vaccination

Question 10

Describe Hep E

Answer 10

Incubation: 21-42 days
Causes food born and waterborne hepatitis. Similar to Hep A but they are able to be distinguished through antibody differences.
- infection can be life threatening in pregnant women.
Prevention: none