B5.027 - Hepatitis Viruses

Question 1

describe HAV

Answer 1

picornoviridae HAV aka enterovirus 72 small (27nm) non enveloped ssRNA (+) replication exclusively in cytoplasm

Question 2

HAV typical serologic course

Answer 2

1-2 months after exposure - fecal HAV, ALT rises total anti HAV develops after 2-4 months, stays for life IgM starts after 1 month, drops around 4

Question 3

is there a vaccine for HAV?

Answer 3

yes, greatly reduced incidence after 1995

Question 4

incubation period, jaundice by age group, complications/clinical sequelae of HAV

Answer 4

avg 30 days 6-14 yo - 40-50% >14 yo - 70-80% fulminant hepatitis cholestatic hepatitis relapsing hepatitis no clinical sequelae

Question 5

HAV vaccine

Answer 5

inactivated vaccine adsorbed onto aluminum hydroxide 94-100% effective

Question 6

what types of enveloped proteins does HBV have

Answer 6

small, medium and large

Question 7

what role does the large protein have

Answer 7

has receptor binding site

Question 8

what proteins does HBV need to make it infectious

Answer 8

small and large proteins

Question 9

why does HBV need small particles

Answer 9

to ensure release of proteins from cell

Question 10

possible mechanisms of HBV induced liver carcinogenesis

Answer 10

1. integration of HBV DNA into host DNA leading to genome instability and mutations 2. DNA damage from chronic infection 3. X protein acts as transcription activator 4. persistent liver damage resulting in hepatocyte proliferation

Question 11

treatment of HBV in order of use

Answer 11

1. tenofovir 2. entecavir 3. telbivudine 4. adefovir 5. lamivudine 6. Pegylated IFN 7. IFN alpha

Question 12

first line treatment of HBV

Answer 12

tenofovir entecavir

Question 13

describe labs for HBV

Answer 13

HBsAg - surface angigen, marker of infectivity when found in serum anti-HBsAg - antibody to HBsAg, marker of immunity anti-HBcAg - marker of past or current infection

Question 14

what is IgM anti-HBc

Answer 14

antibody indicating recent infection with HBV

Question 15

IgG anti HBc

Answer 15

IgG is a subclass of anti HBc indicates older infection with HBV

Question 16

what is HBeAg

Answer 16

Hepatitis B e antigen can only be present if HBsAg is positive. Indicates active infection

Question 17

what is anti HBe

Answer 17

antibody to e antigen may be present in infected or immune person

Question 18

Answer 18

susceptible to HBV infection

Question 19

HBsAg neg

Anti HBc pos

Anti HBs pos

Answer 19

immune to natural infection

Question 20

HBsAg neg

Anti HBc neg

AntiHBs pos

Answer 20

immune due to vaccine

Question 21

HBsAg pos

AntiHBc pos

IgM antiHBc pos

anti HBs neg

Answer 21

acutely infected

Question 22

HBsAg pos

anti HBc pos

IgM antiHBc neg

anti HBs neg

Answer 22

chronically infected

Question 23

HBsAg neg

IgM anti HBc pos

anti HBs neg

Answer 23

1. resolved HBV infection
2. may be susceptible with a false positive anti HBc
3. may have low level chronic infection
4. may be resolving an acute infection

Question 24

describe the two types of HDV infection

Answer 24

coinfection with HBV

Superinfection (ad different times)

Question 25

outcomes of coinfection

Answer 25

3-4% fulminate hepatitis --\> death 90% - acute severe disease --\> recovery 5% - crhonic --\> cirrhosis

Question 26

superinfection outcomes

Answer 26

5% - fulminate hepatitis --\> death 10-15% acute severe disease --\> recovery 80% - chronic hepatitis --\> cirrhosis

Question 27

HCV incubation period, acute illness, case fatality rate from acute infx

Answer 27

6-7 wks mild \<20% low

Question 28

current treatment of HCV

Answer 28

ledipasvir and sofosbuvir

Question 29

describe the developement of HCV associated HCC

Answer 29

viral entry and replication inflammation, cellular growth signals, resistance to apoptosis, oxidative stress, metabolic disorders fibrogenesis, hypoxia, genetic instability, LPS translocation from intestinal microbiota

Question 30

incidence of HCC in different hepatitis

Answer 30

HBV - 60% HCV - 25% neither - 12% both - 3%

Question 31

host of the four types of HEV

Answer 31

1 - humans and pigs 2 - humans 3 - humans and animals

Question 32

route of admin of 4 types of HEV

Answer 32

1, 2 - fecal oral, vertical 3, 4 - zootonic usually swine, environmental and blood transfusion

Question 33

geographical distribution of the 4 types of HEV

Answer 33

1 - mainly asia 2 - MX and west africa 3 - worldwide 4 - china, east asia, central europe, america

Question 34

seasonality of types of HEV

Answer 34

1,2, - flooding/monsoon season 3,4 - no

Question 35

clinical presentation of HEV types

Answer 35

1,2 - acute self limited hepatitis 3,4 - may lead to chronocity in immunosuppressed (3)

Question 36

prognosis/chronic infection of HEV types

Answer 36

1 - high mortality in pregnancy 2 - fulminant hepatitis not noted, no chronic 3, 4 - higher overall mortality relative to 1, and in older adutls, yes chronic