Hepatitis C Virus

Question 1

Classification

Answer 1

Family: Flaviviridae

Genus: Hepacivirus

Species: Hepatitis C

(HintS: occurs during the day, with clothes)

Question 2

Characteristics

Answer 2

• enveloped virus
• +ssRNA
• no virion polymerase

multiple serotypes
High antigenic variability due to:
- envelop protein’s variability
- lack of proofreading 3’ - 5’ exonuclease activity in virion encoded by RNA polymerase —> leads to point mutations

Question 3

Transmission

Answer 3

Mostly via blood:

• Transfusion
• IV drug needles

Sexual transmission
Transmission from mother to child occur as well:
- placenta
- breastfeeding

Question 4

Pathogenesis

Answer 4

• hepatocellular injury caused by cytotoxic T cells
• HCV replication itself does not kill cells (non cytopathic effect)
• 60 to 89% of infections in the chronic carrier state

Question 5

disease

Answer 5

Hepatitis C

Acute:
Jaundice
Hepatomegaly

Chronic:
Associated with hepatocellular carcinoma

Question 6

Microbiological diagnosis

Answer 6

Serologic testing detects antibody to HCV

• acute hepatitis —> ALT rise and fall by 6 months
• chronic —> ( cryoglobulin) serum proteins containing IgM precipitate in the cold

> A PCR based assay for viral load can be used to evaluate whether active infection is present

Question 7

Treatment and prevention

Answer 7

Pegylated alpha interferon + ribavirin mitigates chronic hepatitis but does not eradicate the carrier state

Prevention:
- screening blood before transplant

• there is no vaccine, and hyper immune globulins are not available