ICL 1.6: Hepatitis Viruses I Flashcards
what causes hepatitis?
lots of things!
INFECTIOUS AGENTS
- viruses
- baceria
- parasites
NON-INFECTIOUS
- Alcohol and toxin
- Genetic
- Autoimmune
- Ischemic/shock
what is the virus family, route of transmission, vaccine, and chronic-state of Hepatitis A virus?
picornaviridae = naked (+) ssRNA
fecal-oral transmission
there is a vaccine!
it’s not a chronic virus
what is the virus family, route of transmission, vaccine, and chronic-state of Hepatitis B virus?
hepadnaviridae
parenteral transmission
there is a vaccine!
it can be chronic! can cause cirrhosis or hepatocellular carcinoma
what is the virus family, route of transmission, vaccine, and chronic-state of Hepatitis C virus?
flaviviridae
parenteral transmission
no vaccine available
can be chronic! can cause cirrhosis or hepatocellular carcinoma
what is the virus family, route of transmission, vaccine, and chronic-state of Hepatitis D virus?
virus-like agent, HBV co-infection
parenteral transmission
no vaccine available
can be chronic! it enhances HepB
what is the virus family, route of transmission, vaccine, and chronic-state of Hepatitis E virus?
hepeviridae = naked (+) ssRNA
fecal-oral transmission
no vaccine available
is not chronic
which hepatitis viruses have vaccines available?
hepatitis A
hepatitis B
which hepatitis viruses are transmitted the fecal-oral route?
hepatitis A
hepatitis E
which hepatitis viruses are transmitted the parenteral route?
Hepatitis B, C ,D
parenteral = the passage or transfer of potentially dangerous pathogens via a way other than through the digestive system
how does fecal-oral transmission work?
ingesting contaminated food like vegetables, shellfish, etc. – it’s often foods we don’t cook
hepatitis A and e are the hepatitis viruses transmitted via the fecal-oral route and they are both naked viruses! naked viruses can sit on a counter for a long time and not be broken down and then transmitted to a person; sometimes even if we spray the counter with detergent they still might stick around because they’re not as fragile as envelope viruses
what are the symptoms of HepA?
- jaundice
- fatigue
- abdominal pain
- loss of appetite
- NVD
what is the pathogenesis of HepA?
enteric mucosa –> viremia –> liver –> bile duct –> feces
in the liver there will lymphoid cell infiltration, necrosis of parenchymal cells, and proliferation of Kupffer cells
the severity of the virus correlates with the extent of necrosis
which cell type mediates HepA?
Hepatitis A is a T-cell mediated disease
HLA class I-restricted, virus specific CTLs found in intrahepatic infiltrates from patients
sometimes the virus infects the tissue and your immune response comes in to clear the infected cells and by clearing the cells it’s actually causing tissue damage
this is what happens in liver tissue in HepA which makes it a T-cell mediated disease because your T cells are killing tissue which leads to necrosis!
do people often survive HepA?
majority of cases resolve the infection and recover
it’s pretty rare
which antibodies and enzymes are produced throughout the course of a HepA infection?
first you’re infected through enteric mucosa and there’s viremia
then you generate an IgM response and there’s a spike in ALT
ALT is a liver enzyme which is a marker for liver damage!!
eventually IgM decreases and IgG production increases
this tells us that this is an acute infection because IgM clears the virus and then IgG are memory cells
