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Virology > Hepatitis > Flashcards

Flashcards in Hepatitis Deck (95):
1

HAV class

Picornaviridae

2

HBV class

 

Hepadnaviridae

3

HCV class

 

Flaviviridae

4

Hep D class

 

Satellite, coinfect with B

5

Hep F class

 

???

6

Hep G class

 

Flaviviridae

7

HAV genome and structure

 

ss+RNA

Icosahedral capsid of 4 polypeptides (VP1-4)

Non-enveloped

8

HAV genome distinguishing feature:

 

VPg (protein) on 5' end

9

HAV inactivated by (5 things)

Chlorine

Formalin

Peracetic acid

Beta-propiolactone

UV

10

Replication of HAV (6 steps)

Receptor binding

Uncoating (+RNA)

Translation/Proteolytic processing

Replication

Assembly

Maturation and release

11

HAV produces _____ infection

 

acute

12

HAV incubation period length

 

2-6 weeks

13

2 phases of HAV infection

 

1. Prodrome (flu-like, immune mediated hepatic damage)

2. Icteric (billirubinemia, jaundice, abdominal pain)

  • symptoms wax/wane
  • complete recovery in 99% cases

14

Immunogically, acute HAV infection results in

 

lifelong immunity

15

icterus is an increase in

 

unconjugated bilirubin

16

What happens to conjugated bilirubin?

Water soluble, renal excretion

17

HAV replication occurs in __________ (in body)

Oropharynx or GI tract

18

HAV is shed in the _______

 

bile and feces

19

Does HAV cause viremia?

 

Yes

Brief

20

HAV can be detected...

 

in the stool before symptoms occur

21

Three serological peaks during HAV infection

 

ALT at 2 months

IgM anti-HAV at 3 months (recent infection)

Total anti-HAV (immunity

22

HAV transmission routes (3 categories)

 

Close personal contact

Contaminated food

Blood exposure (rare)

23

Seroprevalence of HAV antibodies

40-70% of adults

24

Serological distinction between acute and past HAV infection

 

IgM = Acute

IgG = Past

25

IgM and IgG are detected by

 

ELISA

26

Is RT PCR useful in detection of HAV?

It may detect earlier than serology, but it is rarely performed

27

HAV vaccines

 

HAVRIX

VAQTA

TWINRX

28

Who is TwinRx not recommended for? What's the dosing schedule?

All patients under 18 years of age.

3 doses @ 0, 1, 6 months

29

HBV genome and structure

 

Genome: Circular dsDNA

Capsid: Icosahedral

Enveloped

30

HBV capsid proteins

1. Core Protein
 (HBcAG)

2. Soluble core protein

(HBeAG)

 

31

What is HBeAG?

Indicator of active HBV replication phase

(it is a variant of the core protein that was modified within the cell)

32

HBV envelope proteins

Surface antige (HBsAG)

3 forms:

  1. S = large
  2. S2 = medium
  3. S1 - small

33

Unique feature of the DNA virus HBV

 

Encodes a RT enzyme

replicates through RNA intermediate

34

The first weird step of HBV replication cycle

Second and third steps?

1. After uncoating, partially double stranded DNA genome is completed by host enzymes -- becomes CCCDNA (Covalently Closed Circular DNA)

2. Four mRNAs are made (one giant one)

3. Goes to cytoplasm where the mRNAs assemble around the big one, and NEGATIVE DNA is made by Reverse Transcriptase

35

What happens after DNA is synthesized in HBV replication?

 

RNA Degrades, and the POSITIVE counterpart to the negative DNA is synthesized.

The envelope forms before this completes

36

HBV released from cell via ______ after assembly

 

Exocytosis

37

HBV causes what kinds of infections?

Acute or chronic

 

38

Acute HBV incubation time

1-6 months

39

Most HBV acute patients are ________

 

asymptomatic

40

Some Acute HBV patients progress to

 

jaundice

41

Few patients progress to _________ during acute HBV infection

 

Fulminant Hepatitis

risks = GI bleed, coma, encephalopathy, ascites, coagulopathy)

42

Survival from acute HBV results in _____________

 

lifelong immunity

(patients will never develop chronic infection)

43

Fulminant Hepatitis requires...

 

Delta agent

44

Chronic HBV patients may...

 

transmit infection throughout life

45

Chronic HBV is definied as

 

longer than 6 months

46

Infants with perinatal HBV infection will...

 

almost always develop CHRONIC hep B infection

47

Chronic HBV =  increased risk of

 

cirrhosis, liver cancer, liver failure

48

HBV infects the liver but does not...

cause direct cytopathology

49

_____ is the leading cause of liver transplantation in the US

Chronic HBV

50

Titer cuves for acute HBV

1st peak = HBsAG

2nd peak = IgM ant-iHBc (Also TOTAL anti-HBc increases here)

Last = anti-HBs

51

Chronic HBV, _____ and ______last much longer in serum titer

HBeAG

HBsAG

52

______ doesn't have a titer peak in chronic HBV

 

anti-HBs

53

HBV transmission

Blood, sex, contact

Transplacental (or perinatal)

54

Areas of highest HBV incidence

Subsaharan Afriaca, SE Asia

55

HBV treatment

 

Acute HBV = (None)

Chronic HBV = Reverse Transcriptase Inhibitors

  1. Lamivudine
  2. Adefovir + alpha-Interferon

56

HBV control (3)

  1. Blood donation screening
  2. Universal precautions
  3. Passive or Active Vax

57

HBV vaccine based on ____. This is recommended for whom? Dosing Schedule?

HBsAG

recommended for young and high risk

3 injections (TwinRX = HAV + HBV together)

58

HCV genus, genome, and structure

Hepacivirus

ss+RNA (looks like Flavivirus)

59

HVC is classified into _______ genotypes. Which are the most common?

 

6 genotypes

Types 1-3 are most common

60

HVC Clades nucleotides differ by 25%, but difference is not correlated to...

 

differences in clinical disease

61

HCV displays classic _____ replication

 

+RNA

(everything happens in the cytoplasm)

62

Acute HCV is _______ in most patients

asymptomatic

63

"Persistent HCV" definition

detectable HCV RNA for more than 6 months from the time of presumed infection

64

Jaundice rate in HCV patients

10-20%

65

__________ is responsible for HCV hepatic damage

 

CMI leading to inflammation of the liver

66

Hepatocellular pathogenesis of HCV (three things)

 

  1. Miscroscopically spotted parenchymal cell degeneration
  2. Necrosis of hepatocytes
  3. MQ accumulate near the degenerating hepatocytes

67

Acute HCV infection shows __________multiplication

 

high, fast

68

Sx of acute HCV coincide with increase in

 

HCV RNA

69

_______ appears in serum after about 8 weeks post-HCV exposure

 

Anti-HCV (EIA-III)

70

Highest source for HCV infection

 

IV drug use

71

Sources (3) with least prevalence for HCV infection

nosocomial

iatrogenic

*perinatal*

 

72

Vertical transmission to fetus occurs in __ % of HCV cases

 

3-10%

73

% risk for HCV transmission from breastfeeding

0%

74

Sexual transmission of HCV is _____ than HIV and HBV

 

Lower

75

HCV transmission between partners may be associated with ....

 

shared use of Razors and toothbrushes

76

Needlestick transmission rate for HCV is _____ than HIV

HIGHER

1.8% versus 0.35%

77

HCV treatments (3)

 

1. Interferon + Ribavirin

2. Pegylated Interferon alpha + Ribavirin

 

(3. Bocepravir + Telaprivir (protease inhibitors))

78

HDV needs _____ for infection

 

HBsAG

 

envelope protein from other virus

79

HDV genus, genome and structure

 

  • Deltavirus
  • ss (-) RNA, Circular
  • Enveloped

80

HDV RNA encodes _________ that complexes with _______

 

Delta agent
 

complexes with RNA

81

Chronic infection with HDV occurs in ___% of cases

 

5%

82

Two types of HDV infections:

 

1. Co-infection (fulminant in 1%)

2. Super-infection (fulminant in 5%)

83

________ HDV infection is far more likely to develop into a chronic infection

 

Superinfection - 80-90% of patients

 

84

What is a HDV superinfection?

 

Infection with HDV in a patient that is already positive for HBsAG

85

Superinfection HDV causes rapid...

 

cirrhosis and hepatocellular carcinoma

86

HDV treatment

 

alpha interferon + lamivudine

87

HEV genome and structure

 

ss+RNA

icosahedral

nonenveloped

 

88

Number of HEV genotypes? Which cause human diseases?

Four

Only #1 causes human disease

89

Phases of HEV infection

Prodromal and icteric

90

HEV infection is _________

 

self-limited

91

HEV...E stands for

 

Enteric + Epidemic

92

HEV spread via...

 

fecal oral route

93

Epidemics of HEV reporded where...

 

fecal contamination of drinking water is common

94

Most important prevention measure for HEV is

 

Sanitation

95

HEV chronic infection length

 

HEV doesn't cause chronic infection