Hepatitis Viruses

Question 1

What are the common symptoms of hepatitis infection?

Answer 1

Fatigue, Nausea, Fever
Abd Pain
Dark Yellow Urine

Question 2

What type of virus is HAV and how many serotypes?

Answer 2

RNA Picornavirus
1x Serotype world-wide
–Vaccine Available–

Question 3

What is the most common mode of transmission of HAV?

Answer 3

fecal-oral, improper food handling, contaminated food

Question 4

What is unique about the HAV and capsid?

Answer 4

Highly Stable. Resistant to acid, deterogent, and drying, thus the reason it is able to contaminate surfaces/foods.

Question 5

What is the common HAV course and who is most effected?

Answer 5

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.

Question 6

Are there any long term infections or complications associated with HAV?

Answer 6

No. There is NO Chronic Infection.

Question 7

Who are recommended to get the HAV Vaccine?

Answer 7

Infants
Traveling to HAV edemic areas
Individuals with chronic liver disease
Handlers of the virus

Question 8

What hepatitis virus is associated with infected waters and travel to endemic areas?

Answer 8

Hepatitis E Virus

–Enteric Virus, acute, will resolve

Question 9

What is unique about disease pathology and age of infection of HBV?

Answer 9

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+.

Question 10

What are the risk factors and main modes of transmission of HBV?

Answer 10

Risk factors: IV drug use, blood products, and sexual encounters
Main Modes: Neonatal transmission and sexual transmission

Question 11

What are the steps HBV undergoes in infecting a cell?

Answer 11

• 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

Question 12

What is a unique factor that HBV releases?

Answer 12

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–

Question 13

What is the HBV disease course?

Answer 13

• 2 month incubation time, infects hepatocytes in the liver

Abd pain, nausea, malaise, jaundice, dark urine

Question 14

What happens if you are infected with Hepatitis D virus after getting infected with HBV?

Answer 14

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–

Question 15

What is unique about the HDV infection?

Answer 15

Hepatitis D virus can ONLY infect cells that have an active HBV virus, due to it becoming packaged in HBV capsids.

Question 16

Why does Hep B chronic infection correlate to hepatic carcinoma?

Answer 16

• chronic inflammation in the liver
• frequent reproduction of hepatocytes = more errors
• destabilizing DNA after virus integrates
• Expression of protein “X” that reduces p53 activity

Question 17

How does the Vaccine for HBV work?

Answer 17

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.

Question 18

What is the key to administering the HBV vaccine?

Answer 18

Sooner it is given the better!

Question 19

What kind of virus is the Hepatitis C?

Answer 19

• Most prevalent - Flavivirus +ssRNA, very error prone, thus many species/serotypes.
  Associates with vLDL and lipid membranes

Question 20

What is the cause of liver damage with HCV?

Answer 20

Robust immune response during replication, primary cause of liver damage, not the virus.
Hepatocyte Specific

Question 21

What kind of virus is HCV and how does it replicate?

Answer 21

+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.

Question 22

What is the most common source of infection for HCV?

Answer 22

• IV drug use &laquo_space;Most

- sexual transmission

Question 23

What are the differences in risk for chronic infection between HBV and HCV?

Answer 23

Hep B - has a much lower chance of developing a chronic infection
Hep C - very high chance of developing chronic infection ~85% chance.

Question 24

How does HCV increase risks of hepatocarcinoma?

Answer 24

• 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

Question 25

Why HCV selective to replication in liver cells?

Answer 25

HCV - +RNA binds miRNA 122, which amplifies its translation in the cytoplasm
miRNA is almost exclusively expressed in the Liver, thus that will be the highest concentration of HCV

Question 26

What gene has important polymorphisms that influence the chance of clearing the virus vs chronic infection?

Answer 26

IL28b gene - IFN-gamma expression

Question 27

What is the best way to prevent HBV and HCV?

Answer 27

Safe Lifestyle Choices and Prevention