Hepatitis Viruses Flashcards
(27 cards)
What are the common symptoms of hepatitis infection?
Fatigue, Nausea, Fever
Abd Pain
Dark Yellow Urine
What type of virus is HAV and how many serotypes?
RNA Picornavirus
1x Serotype world-wide
–Vaccine Available–
What is the most common mode of transmission of HAV?
fecal-oral, improper food handling, contaminated food
What is unique about the HAV and capsid?
Highly Stable. Resistant to acid, deterogent, and drying, thus the reason it is able to contaminate surfaces/foods.
What is the common HAV course and who is most effected?
Approximately 30 days for incubation. Viruses shed in stool.
The older the infected individual is, the higher chance of jaundice and liver pathology, but viral load will resolve on it’s own granting lifetime immunity.
Are there any long term infections or complications associated with HAV?
No. There is NO Chronic Infection.
Who are recommended to get the HAV Vaccine?
Infants
Traveling to HAV edemic areas
Individuals with chronic liver disease
Handlers of the virus
What hepatitis virus is associated with infected waters and travel to endemic areas?
Hepatitis E Virus
–Enteric Virus, acute, will resolve
What is unique about disease pathology and age of infection of HBV?
The earlier an infant gets infected with HAB, then the higher the chance they will develop chronic/latent infection. The older the lower the chance 5+.
What are the risk factors and main modes of transmission of HBV?
Risk factors: IV drug use, blood products, and sexual encounters
Main Modes: Neonatal transmission and sexual transmission
What are the steps HBV undergoes in infecting a cell?
- Enters cell as partial-dsDNA and becomes completely ds-DNA inside cytoplasm
- translocates to nucleus to be transcribed into RNA
- Encodes Reverse Transcriptase that makes the partial-dsDNA from the mRNA for replication - budding.
- DNA in nucleus can integrate or not - depending on age
What is a unique factor that HBV releases?
HAB releases HgsAg, which is the antigen of the virus without the viral particles
Envelope has the same antigen as the HgsAg.
–Both releases at the same time–
What is the HBV disease course?
- 2 month incubation time, infects hepatocytes in the liver
Abd pain, nausea, malaise, jaundice, dark urine
What happens if you are infected with Hepatitis D virus after getting infected with HBV?
If you get infected with HDV while you currently have HBV, then there is a significantly increased risk of the infection becoming chronic.
–if infected at the same time, then no increased risk–
What is unique about the HDV infection?
Hepatitis D virus can ONLY infect cells that have an active HBV virus, due to it becoming packaged in HBV capsids.
Why does Hep B chronic infection correlate to hepatic carcinoma?
- chronic inflammation in the liver
- frequent reproduction of hepatocytes = more errors
- destabilizing DNA after virus integrates
- Expression of protein “X” that reduces p53 activity
How does the Vaccine for HBV work?
HgsAg - antigen, which the body can make antibodies to, so when the individual is exposed to HBV the antibodies prevent the virus from getting to the liver hepatocytes while body kills off the rest.
What is the key to administering the HBV vaccine?
Sooner it is given the better!
What kind of virus is the Hepatitis C?
- Most prevalent - Flavivirus +ssRNA, very error prone, thus many species/serotypes.
Associates with vLDL and lipid membranes
What is the cause of liver damage with HCV?
Robust immune response during replication, primary cause of liver damage, not the virus.
Hepatocyte Specific
What kind of virus is HCV and how does it replicate?
+ssRNA virus enters cell and is translated into polyprotein in the cytoplasm via IRES-mediated, then creates membranous web for replication/packaging of virions to be released.
What is the most common source of infection for HCV?
- IV drug use «_space;Most
- sexual transmission
What are the differences in risk for chronic infection between HBV and HCV?
Hep B - has a much lower chance of developing a chronic infection
Hep C - very high chance of developing chronic infection ~85% chance.
How does HCV increase risks of hepatocarcinoma?
- Core protein interact with tumor suppressor proteins preventing functionality
- Core protein induces Steatosis - increasing chronic inflammation
- Envelope proteins inhibit NK cells
- Nonstructural proteins enhance cell proliferation and suppress tumor suppression proteins
