Hepatitis B, C & E and Parasites Flashcards
describe Hep C
non-A, non-B post-transfusion
Flaviviridae
enveloped, circular (+) ssRNA
why is it difficult to make a vaccine for Hep C?
Hep C carries its own RNA-dependent RNA polymerase which is error prone → increased mutations → many different variants
the target of Hep C is ____ and ____
the target of Hep C is hepatocytes and B-cells
describe the replication of Hep C
undergoes replication using a (-) RNA as an intermediate
uptake of Hep C is facilitated by a ____
uptake of Hep C is facilitated by a lipoprotein coat
HCV inhibits ___ and ___ action which leads to…. (3 results)
HCV inhibits apoptosis and IFN-gamma action which leads to:
- prevent cell death
- inhibits host protections
- promote persistent infection
list the 3 modes of transmission for Hep C
- parenteral: IV drug users, acupuncture, tattooing, health workers (increased risk)
-
sexual contact (uncommon): high risk activity
- coinfection of HIV increases transmission
- perinatal: mother (HCV-Ab+) → infant
describe the pathogenesis of HCV
- HCV inhibits apoptosis → persistent infxn → liver disease
- HCV inhibits IFN-gamma action → chronic infxn
- HCV-Ab is not protective
____ is the gold standard for HCV diagnosis
RNA genome detection (RT-PCR) is the gold standard for HCV diagnosis
describe the prevention of HCV
- blood and organ donor screening
- universal blood and bodily fluid precautions
- no vaccine
describe hepatitis D virus
delta agent
enveloped, circular (-ve) ssRNA (rod shaped)
describe the L and S antigen of HDV
- L antigen suppresses HBV replication
- S antigen transactivates HDV RNA replication
describe the replication of HDV
- HDV requires replicating HBV
- HBV provides viral coat (HBsAg + delta antigen) for HDV
describe what acute HDV infection can progress to
- acute → fulminant hepatitis, cirrhosis, chronic HDV infection
HDV only replicates/causes disease in individuals with ____
HDV only replicates/causes disease in individuals with active HBV
describe coinfection and superinfection
-
coinfection: both HBV + delta agent
- HBV establish first for delta agent replication
-
superinfection: chronic HBV infected with delta agent
- rapid disease progression
describe HEV
enteric, non-A, non-B
similar to Calciviruses
non-enveloped (+ve) ssRNA
describe the pathogenesis of HEV
- HEV infxns are usually self-limiting, only acute disease
- HEV infection in pregnant women can lead to fulminant hepatitis
HEV infection in ______ can lead to fulminant hepatitis
HEV infection in pregnant women can lead to fulminant hepatitis
HEV infection in pregnant women can lead to ____
HEV infection in pregnant women can lead to fulminant hepatitis
describe the Fasciola spp.
- sheep liver fluke
- fascioliasis
- definitive host: sheep and cattle
- intermediate host: snail
- human incidental hosts: contaminated water and watercress
in a Fasciola spp. infection, mammals ingest ___
in a Fasciola spp. infection, mammals ingest metacercariae
the diagnostic form of Fasciola spp. is ___ in feces
the diagnostic form of Fasciola spp. is eggs in feces
describe the acute vs. chronic phase of Fasciola spp. infection
-
acute phase (2-4 months, migration of larvae)
- generalized allergic/toxic reactions; fever, generalized or RUQ pain, hepatomegaly, loss of appetite, flatulence, nausea and diarrhea, cough, SOB, chest pain, urticaria
-
chronic phase
- biliary colic, nausea, intolerance to fatty food, RUQ pain, epigastric pain, obstructive jaundice, pruritus, biliary lithiasis, blockade in biliary tract and inflammation of gallbladder
