Wk5 Viral Hepatitis

Question 1

Class IV SS(+) RNA

Icosahedral

Nonenveloped

Picornoviridae

Enterovirus

Answer 1

Hep A

Question 2

Strength of Hep A viral capsid?

Answer 2

stable at pH 1

**inactivated by chlorine, formalin, UV radiation

Question 3

Hep A route of infx:

Answer 3

fecal - oral

Question 4

Surface receptor on cells infected by Hep A:

What cells are they?

Answer 4

HAVCR-1

liver cells, T cells

Question 5

How/when Hep A gets to stool:

Answer 5

replicates in liver

shed into stool 10 days before pt gets jaundice

Question 6

Pathogenesis of Hep A:

Answer 6

immune response of cytotoxic T cells

HAV itself is not cytotoxic

Question 7

Why is Hep A spread so easily?

Answer 7

contagious 10-14 days before sx show up

many have asymptomatic but contagious infx

Question 8

Onset of Hep A sx:

Answer 8

15-50 days post exposure

Question 9

Sx of Hep A:

Answer 9

4-6 days

fever

fatigue

nausea

loss of appetite

abd pain

dark urine

jaundice

99% have full recovery

Question 10

Lab dx fo Hep A:

Answer 10

anti-HAV IgM on ELISA

Question 11

Prophylactic tx for HAV:

Answer 11

immune globulin serum

VACCINE

• 2 dose
• Killed HAV vaccine

Question 12

Class IV SS(+) RNA

Icosahedral

Nonenveloped

Calciviridae

Answer 12

Hep E

Question 13

Particularly dangerous for pregnant women:

Answer 13

Hep E

Question 14

Sx of HEV:

Answer 14

Very similar to HepA, slightly later onset, slightly more severe

no treatment or vaccine

fever, fatigue, nausea, loss of appetite, abd pain, dark urine, jaundice

Question 15

Class VII DS(partial) Circular DNA

Icosahedral

ENVELOPED

Hepadnaviridae

Answer 15

Hep B

Question 16

Liver cell receptors for HBV docking:

Answer 16

transferrin

asialoglycoprotein

annexin V protein

Question 17

HBV viral bonding protein:

Answer 17

HBsAg

Question 18

What determines course of HBV and whether acute/chronic, asymptomatic/symptomatic disease develops?

Answer 18

host immune respone

if effective, disease resolves

Question 19

Antibodies signaling protection/neutralization of HBV:

Answer 19

anti-HBsAg

”s” = surface antigen

Question 20

What is the HBs “window”?

Answer 20

time between decline of serum HBsAg and detection of Anti-HBs antibodies

???

Question 21

What happens in limited cell-mediated immune response to HBV?

Answer 21

chronic disease (mild s) –>

1. fulminant hepatitis (can be expedited by addition of HDV)
2. primary hepatocellular carcinoma
3. Cirrhosis

Question 22

Serology for chronic HBV:

Answer 22

Serum HBsAg, HBeAg

Serum Anti-HBc……maybe anti-HBe (late acute)

???

Question 23

source or HBV spread:

Answer 23

blood

body fluids including saliva and milk

Question 24

Onset of sx in HBV:

Answer 24

up to 45 days

**virus starts replicating 3 days post infx

Question 25

Review slide

Answer 25

37-38

Question 26

Difference in serology of person vaccinated against HBV and healthy person who had the virus:

Answer 26

Vaccinated: Anti-HBs only Prior infx: Anti-HBs + Anti-HBc +/- Anti-HBe

Question 27

What does it mean if follow up serology of known HBV infx comes back negative for HBsAg and Anti-HBs Ab's?

Answer 27

Patient is in "window" period and test needs to be repeated

Question 28

In chronic HBV, how to differentiate serologically between active viral replication and non-replicating virus?

Answer 28

active viral replication will be HBeAg positive and anti-HBe negative

Question 29

Follow up for non-replicating chronic HBV infx:

Answer 29

HBV DNA test serum ALT if elevated --> liver biopsy if low/normal --> monitor

Question 30

Vaccination for HBV:

Answer 30

infants/children high risk groups

Question 31

Prophylaxis for HBV:

Answer 31

immune globulin serum newborns to HBsAg+ mothers individuals within one week of exposure

Question 32

Tx for chronic HBV:

Answer 32

HBV polymerase inhibitors nucleoside analogues INF-a

Question 33

Class V SS(-) RNA Circular ENVELOPED Icosahedral

Answer 33

Hep D "Deltavirus"

Question 34

Why does HDV require prior or co- HBV infx:

Answer 34

needs HBsAg for packaging

Question 35

Chronic HBV carrier subsequently infx with HDV = ?

Answer 35

superinfection **progresses more rapidly than co-infection

Question 36

Tx for HDV:

Answer 36

clear HBV

Question 37

Class IV SS(+) RNA ENVELOPED Icosahedral Flaviviridae

Answer 37

Hep C

Question 38

Test for HCV:

Answer 38

Anti-HCV (total)

Question 39

If Anti-HCV is positive, order:

Answer 39

Quantitative RT-PCR for genome in serum

Question 40

If quant RT-PCR for HCV is positive?

Answer 40

anti-viral therapy

Question 41

If quant RT-PCR but liver enzymes remain elevated in 1-2 months?

Answer 41

repeat test **continued positive Anti-HCV + negative RT-PCR = prior infx

Question 42

Liver cell surface target of HCV:

Answer 42

CD81 -- tetraspanin **also on B-cells

Question 43

How does HCV promote persistent infx?

Answer 43

inhibits apoptosis inhibits INF-a

Question 44

Gold standard dx test for HCV and tx planning:

Answer 44

RT-PCR -- detection, quantitation, genotyping

Question 45

Tx for Hep C:

Answer 45

INF-a ribavirin NS5A/B inhibitors

Question 46

Class IV SS (+) RNA ENVELOPED icosahedral Flaviviridae Flavivirus

Answer 46

Yellow Fever

Question 47

Route of infx for yellow fever:

Answer 47

Aedes mosquito

Question 48

Disease course for yellow fever:

Answer 48

cytolitic --> serious life-threatening infx both humoral and cellular immune response destroys tissue

Question 49

Prevention of Yellow fever?

Answer 49

live-attenuated vaccine