HCV lecture 1 epidemiology Flashcards
what is hepatitis
inflammation of the liver
what is the diagnosis of hepatitis
look at serum levels of alanine aminotransferase. look at ultrasound or magnetic resonance elastography of the liver. do a liver biopsy
what are the different types of hepatitis viruses
hepatitis A and E: non-envelope, enteric transmission, acute hepatitis.
B,C,D: enveloped, parenteral transmission, chronic
what are hepatocytes
metabolise carbohydrates, fats, proteins. produce serum components. carry out detoxification and produce bile.
how many infected people are there today
58 million
what are the targets for 2030 regarding HCV
new cases reduced to 350k per yr. deaths to 140k. cure rate to 90%
what is the most common route of transmission
parenteral.
how is the nucleotide sequence highly variable
isolates are grouped into 8 groups and they have uneven geographical distribution.
how does the antibody test for HCV work
blood test for antibodies. antibodies remain when infection is cleared so there may not be actual active HCV present.
what is the main genotype in Egypt and why
type 4 because of mass treatment campaign against schistosommiasis. they re used glass syringes.
how was the HCV genome cloned
1) high titre human serum
2) centrifuge to concentrate virus
3) extract RNA
4) reverse transcriptase
5) clone cDNA into bacteriophage
6) infect e.coli with bacteriophage library
7) take imprint of plate with nitrocellulose membrane
8) probe membrane with antiserum from NANBH patients
9) pick plaques and sequence
describe the HCV genome and polyprotein
belongs to the Flaviviridae family it is linear and single stranded.
positive sense RNA 9.5 kb.
structural proteins: E1, E2 for envelope glycoproteins.
non-structural: NS2, NS3 and NS4A-used for protease, NS4B, NS5A, NS5B- for RNA dependent RNA polymerase.
how are infectious molecular clones of HCV made
1) pHCV - cDNA copy of viral genome
2) in vitro RNA transcription
3) direct intrahepatic injection of chimpanzees
4) increasing viral titre to week 8
can these infectious clones replicate in cultured cells
no
