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Flashcards in Wk5 Viral Hepatitis Deck (49)
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1
Q

Class IV SS(+) RNA

Icosahedral

Nonenveloped

Picornoviridae

Enterovirus

A

Hep A

2
Q

Strength of Hep A viral capsid?

A

stable at pH 1

**inactivated by chlorine, formalin, UV radiation

3
Q

Hep A route of infx:

A

fecal - oral

4
Q

Surface receptor on cells infected by Hep A:

What cells are they?

A

HAVCR-1

liver cells, T cells

5
Q

How/when Hep A gets to stool:

A

replicates in liver

shed into stool 10 days before pt gets jaundice

6
Q

Pathogenesis of Hep A:

A

immune response of cytotoxic T cells

HAV itself is not cytotoxic

7
Q

Why is Hep A spread so easily?

A

contagious 10-14 days before sx show up

many have asymptomatic but contagious infx

8
Q

Onset of Hep A sx:

A

15-50 days post exposure

9
Q

Sx of Hep A:

A

4-6 days

fever

fatigue

nausea

loss of appetite

abd pain

dark urine

jaundice

99% have full recovery

10
Q

Lab dx fo Hep A:

A

anti-HAV IgM on ELISA

11
Q

Prophylactic tx for HAV:

A

immune globulin serum

VACCINE

  • 2 dose
  • Killed HAV vaccine
12
Q

Class IV SS(+) RNA

Icosahedral

Nonenveloped

Calciviridae

A

Hep E

13
Q

Particularly dangerous for pregnant women:

A

Hep E

14
Q

Sx of HEV:

A

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

15
Q

Class VII DS(partial) Circular DNA

Icosahedral

ENVELOPED

Hepadnaviridae

A

Hep B

16
Q

Liver cell receptors for HBV docking:

A

transferrin

asialoglycoprotein

annexin V protein

17
Q

HBV viral bonding protein:

A

HBsAg

18
Q

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

A

host immune respone

if effective, disease resolves

19
Q

Antibodies signaling protection/neutralization of HBV:

A

anti-HBsAg

”s” = surface antigen

20
Q

What is the HBs “window”?

A

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

???

21
Q

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

A

chronic disease (mild s) –>

  1. fulminant hepatitis (can be expedited by addition of HDV)
  2. primary hepatocellular carcinoma
  3. Cirrhosis
22
Q

Serology for chronic HBV:

A

Serum HBsAg, HBeAg

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

???

23
Q

source or HBV spread:

A

blood

body fluids including saliva and milk

24
Q

Onset of sx in HBV:

A

up to 45 days

**virus starts replicating 3 days post infx

25
Q

Review slide

A

37-38

26
Q

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

A

Vaccinated: Anti-HBs only

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

27
Q

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

A

Patient is in “window” period and test needs to be repeated

28
Q

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

A

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

29
Q

Follow up for non-replicating chronic HBV infx:

A

HBV DNA test
serum ALT

if elevated –> liver biopsy

if low/normal –> monitor

30
Q

Vaccination for HBV:

A

infants/children

high risk groups

31
Q

Prophylaxis for HBV:

A

immune globulin serum

newborns to HBsAg+ mothers

individuals within one week of exposure

32
Q

Tx for chronic HBV:

A

HBV polymerase inhibitors

nucleoside analogues

INF-a

33
Q

Class V SS(-) RNA Circular

ENVELOPED

Icosahedral

A

Hep D

“Deltavirus”

34
Q

Why does HDV require prior or co- HBV infx:

A

needs HBsAg for packaging

35
Q

Chronic HBV carrier subsequently infx with HDV = ?

A

superinfection

**progresses more rapidly than co-infection

36
Q

Tx for HDV:

A

clear HBV

37
Q

Class IV SS(+) RNA

ENVELOPED

Icosahedral

Flaviviridae

A

Hep C

38
Q

Test for HCV:

A

Anti-HCV (total)

39
Q

If Anti-HCV is positive, order:

A

Quantitative RT-PCR for genome in serum

40
Q

If quant RT-PCR for HCV is positive?

A

anti-viral therapy

41
Q

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

A

repeat test

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

42
Q

Liver cell surface target of HCV:

A

CD81 – tetraspanin

**also on B-cells

43
Q

How does HCV promote persistent infx?

A

inhibits apoptosis

inhibits INF-a

44
Q

Gold standard dx test for HCV and tx planning:

A

RT-PCR – detection, quantitation, genotyping

45
Q

Tx for Hep C:

A

INF-a

ribavirin

NS5A/B inhibitors

46
Q

Class IV SS (+) RNA

ENVELOPED

icosahedral

Flaviviridae

Flavivirus

A

Yellow Fever

47
Q

Route of infx for yellow fever:

A

Aedes mosquito

48
Q

Disease course for yellow fever:

A

cytolitic –> serious life-threatening infx

both humoral and cellular immune response destroys tissue

49
Q

Prevention of Yellow fever?

A

live-attenuated vaccine