11.2 Hepatitis Flashcards
List the hepatitis viruses and their classification
HAV - picornaviridae
HBV - hepadnaviridae
HCV - flaviviridae
HDV - deltavirus
HEV - caliciviridae
GBV - flavi-like viruses
What is the major difference in transmission between HAV and HBV
Enteric vs paternal
Why is it difficult to grow HAV in cell culture?
They only replicate in Kupffer cells or hepatocytes
How is the course of disease cased by HEV different from that caused by HAV?
Course of disease is similar to HAV but there is a longer incubation period, it occurs in adults and adolescents rather than children, the chance for person to person transmission is low and the mortality rate is high.
Describe the particles produced by a HBV infection
Dane particle ,, 42nm (double shell), complete virion, infectious
Spheres and filaments ,, 22nm sphere, consist of surface antigen, no DNA and not infectious
List control measures for HBV
- The carrier state is treated
Why is there no vaccine for HEV or HCV?
It cannot be grown in a culture
How is HDV dependant on HBV?
HBsAg which is made in excess by HBV is used as an outer coat by HDV
What is a ribosyme and how does it work?
It is an RNA that acts like an enzyme as it self cleaves RNA motifs, anneals two RNA molecules at complimentary sequences and one RNA acts as a ribozyme whereas the other acts as a substrate and is cleaved and they then dissociate
What is the clinical course for HCV?
Slow progressive asymptomatic hepatitis with persistent viraemia cirrhosis may take up to 20 years to develop infiltrating lymphocytes in portal tracts of liver and bile ducts.
CMI is prominent but does not clear infection
How is HCV released?
Assembly of the virus takes place at the endoplasmic reticulum and then buds into the ER where carbohydrate addition and modification occurs. Then proceeds to the Golgi apparatus to finally be released by exocytosis.
