Microbioloby-Viral Hepatitis Flashcards Preview

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Flashcards in Microbioloby-Viral Hepatitis Deck (32):
1

What hepatitis viruses are associated with fecal oral transmission?

A & E

2

What hepatitis viruses are associated with parenteral transmission?

B/D and C

3

HAV virus type

Picornavirus, ssRNA

4

HBV virus type 

Hepadnavirus, Partially DS DNA

5

Why would HIV drugs reduce cancer rates in Asia?

HBV is a major cause of liver cancer. 1 in 5 people in Asian countries has HBV. The virus uses reverse transcriptases on an RNA template to form its DNA template, which would be affected by HIV drugs.

6

HCV virus type

Flavivirus, ssRNA

7

HDV virus type

Plant viroid, ssRNA

8

A vaccine for HBV would also cover what other hepatitis virus?

HDV, it is dependent on HBV previous or co-infection to infect.

9

Hepatitis virus that most often causes chronic liver disease?

HCV.

10

HEV virus type

Calicivirus, ssRNA

11

Which hepatitis virus is mild in healthy individuals and severe in pregnant women?

HEV, note that it is more prevalent in east and south asia.

12

Why do most hepatitis viruses not present with symptoms until 2 weeks after infection?

The viruses are not cytotoxic. They infect hepatocytes, hepatocytes present viral protein on MHC-I, CD8+ cells are activated and induce apoptosis in the hepatocytes. It takes 10-14 days for this immune reaction to occur and that causes symptoms.

13

A 33 year old inmate presents with fever, fatigue, nausea, vomiting, decreased appetite and abdominal pain. Physical exam reveals scleral icterus. There are several other inmates that had similar symptoms in the past 3 months. Is this inmate at risk for development of chronic hepatitis or hepatocellular carcinoma?

No, this is likely HAV. It is spread fecal orally and transmits well in institutions with poor sanitation like a prison. Note that it is spread in fecal matter by hepatic infection and secretion in bile.

14

A 33 year old inmate presents with fever, fatigue, nausea, vomiting, decreased appetite and abdominal pain. Physical exam reveals scleral icterus. There are several other inmates that had similar symptoms in the past 3 months. What blood levels could you test to see if he is combating the infection or has overcome the infection?

HAV surface antigen: indicates current infection. HAV-specific IgM: combating the infection. HAV-specific IgG: overcame and immune to infection.

15

A 33 year old inmate presents with fever, fatigue, nausea, vomiting, decreased appetite and abdominal pain. Physical exam reveals scleral icterus. There are several other inmates that had similar symptoms in the past 3 months. What could you give this patient for treatment?

HAV-specific IgG. The virus lives mostly in the blood stream and giving this will essentially wipe it out.

16

A 22 year old pregnant woman in India presents with fever, fatigue, nausea, vomiting and abdominal pain. She also has a miscarriage. What is the best way to prevent this sort of infection?

HEV has several different serotypes and IgG Ab is not curative. Prevention is the best measure.

17

What part of the image shown below is infectious?

HBV’s infectious particle is the Dane particle (42 nm). The other 22 nm particles are spheres and filaments that contain HBsAG. These are produced in large excess over the infectious particles to decoy the immune system.

18

What other diseases are associated with HBV?

Since it forms so many antigens, it can induce immune-complex symptoms in the joints, eyes etc.

19

How does HBV infect the host?

Viral particle binds to hepatocyte and viral envelope fuses and releases core into cytoplasm. Polymerase inside core completes synthesis of DNA. DNA enters nucleus and becomes a circular plasmid DNA. RNA is transcribed, packaged into core and reverse transcriptase makes a partial dsDNA to package into the viral particle before it exits the hepatocyte.

20

What serology marker tells you that someone with HBV is very infectious?

HBeAG

21

What increases your risk of being a chronic HBV carrier? What major complications come with this?

Infection in infancy. Chronic HBV carriers have increased risk for liver cirrhosis and primary hepatocellular carcinoma.

22

What is responsible for development of hepatocellular carcinoma?

Chronic liver damage and regeneration.

23

3 major ways HBV is transmitted

Sexual, parenteral, and perinatal

24

What antibody against HBV is protective?

Anti-HBsAG prevents HBV binding to host cells. Anti-HBcAG is not protective, it just attacks the core of the virus when it is exposed. Antie-HBeAG is not protecting, it just tells you that the patient was infectious at some point.

25

What does + HBsAG mean? + HBsAb? Anti-HBcAG IgM? Anti-HBcAG IgG? HBeAG? Anti-HBeAG? HBV-DNA?

HBsAG: general marker for infection. HBsAb: recovery or immunity to HBV. Anti-HBc IgM: acute infection. Anti-HBc IgG: past or chronic infection. HBeAG: active viral replication. Antie-HBeAG: virus is not replicating. HBV-DNA: active viral replication

26

How do you prevent perinatal transmission of HBV from an infected mother?

Passive immunization with HBV surface IgG within 24 hours of birth.

27

What leads to the most serious type of hepatitis D infection (fulminant hepatitis)?

Superimposed HBV infection, commonly seen in drug abusers.

28

What test is generally used to detect HCV infection?

HCV antibody for core, NS3, NS4 and NS5. Note that this antibody does not appear until 7-8 weeks after initial infection.

29

What can you use to diagnose HCV infection in the acute phase?

HCV-RNA PCR, this is mainly used to monitor response to antiviral therapy.

30

Why do you see such fluctuation in ALT levels when people are infected by HCV?

As the body adapts to manage the infection, the virus adapts to evade the immune response and the cycle continues on.

31

How do you treat HCV?

Inteferon alpha (inhibits viral replication) + pegylated interferon alpha (to stabilize IF alpha) + Ribavirin (does not work alone). Note that 50% of people relapse after treatment is completed.

32

New expensive treatment for HCV?

NS3/4A protease inhibitors

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