Hepatitis Viruses Flashcards
What are Hepatitis Viruses
Viruses that specifically target the liver
where do Hepatitis Viruses primarily infect and replicate
in hepatocytes
what’s the symptome theme for Hepatitis Viruses
Liver damage from virus and host response
severity of Hepatitis viruses
Some acute infection, some chronic infecions
Prevalence of Different Hepatitis VIruses
HDV and HEV very rare in US
we have a good amount of HAV, HBV, and HCV
is HAV usually acute or chronic
Acute
Is HBV usually acute or chronic
about 50:50
Is HBC usually acute or chronic
Chronic
What type of VIrus is HBV
Hepadnaviridae
what is the Genome of HBV
dsDNA (smallest genome of the human virus)
what is the Virion of HBV
enveloped
PRoteins of HBV
HBsAg-S: Virion assembly HBsAG-M: unknown function HBsAG-L: cell attachment HBcAg: capside Pol: reverse transcriptase
Growing HBV on a cell culture
Cannot be done
Replication of HBV requires
RNA intermediate and therefore reverse transcriptase
what is the template for transcpirtion of HBV
cccDNA
what is need for HBV transcption
Liver specific transcription facters
what does HBV produce that is found in infected people
Many empty particles/capsids (HBsAy)- “sloppy virus”
what does the dsDNA of HBV look like outside and inside the cell
outside: rcDNA: not fully double standed
inside: repaired by cellular machinery to make cccDNA
How to test if someone has HBV
test for empty particles in blood stream
how does one get HBV
Sex and Drugs
Incubation of Hepatitis B VIrus
30-180 days
Symptoms of HBV
General MAlaise, ANorexia, Vomiting, Fatigue, cough, serum-like sickness
Jaundice, elevated Alainine transaminase levels
Revovery from HBV (acute)
3-4 months after onset of jaundice
what results from a chronic HBV infection
high levels of antibodies in blood stream plus some sickness at times
how common is HBV chronic disease
5% of cases
what marks HBV chronic
Presence of HBsAg in blood for >6 months
marked by poor IgG response
Chronic HBV symptoms
SPoradic epidosde of hepatitis
Cirrhosis of the liver
Increased risk for heaptocellular carcinoma (HCC)
why would someone get hepatocellular carcinoma because of HBV
HBV X gene/protein has tumorigenic potential
HBV prevention and control
Vaccination
Chronic:
Interferon- alpha therapay
Nucleoside analogs: adefovir, lamivudine, tenofovir
what kind of Vaccine is the HBV vaccine
First reombinant vacccine for humans
Giving the HBV vaccine
Multiple inoculations
HBV vaccine and chronic infections
does not owrk
what type of agent is HDV
subviral agent
commonality of subviral agents
rare in human viruses
examples of subviral agents
HBV and Adeno-associated virus (AAV)
what does AAV require to infect
adenovirus infection
what does HDV require
active HBV infection
what does the HDV virus encode
RNA for a single protein
what type of Virus is HCV
Flaviviridae
Genome of HCV
(+)ssRNA
Virion of HCV
enveloped
Proteins of HCV
E1&E2: attachment and entry
C: Core
Various non-structural
How does HCV genome replicate
Genome passed into cytoplasm
how does HCV get into cell
receptor mediated endocytosis, goes into endosome, lowers pH, pore forms and genome is pussed out into the cytoplasm, but capside never leaves endosome
Symptoms of HCV compared to HBV
HCV is more mild
Disease by HCV
Extrahepatic disease
extrahepatic disease caused by HCV
mixed cryoglobulinemia
mixed cryoglobulinemia
antibody and virus complexes deposit in other tissures (kidneys) elicitinga an immune response and subseqquent tissue damge
treating HCV
SEPATIER, treats some denotypes
No Vaccine
How does one get HAV
ingestion of fecally contaminated food and water
absorbed through intestine and moves to liver via portal system
Incubation of HAV
15-40 days
Symptoms of HAV
consistent with hepatitis infection: Maliase, anorexia, vomitiing, jaundice
who gets worse HAV infections
Adults
resolution time of HAV
8 weeks post infection
Prevention of HAV
VAccine
Vaccine for HAV
killed/inactivated
response of HAV
fecal HAV - 2 weeks
4 week IgM- initatl response
when 12 weeks IgG - cellular mediated
what does HEV cause
foodborne and waterborne hepatitis
Disease of HEV is like
similar to that of HAV
separating HAV from HEV
serolofy
HEV and pregnant women
lifethreatenign
PRevention of HEV
no prevention, but vaccine under development
HAV biology is similar to
Poliovius