Microbiology: Hepatitis B

Front 1

What are common presenting symptoms?

Back 1

1) fevers
2) chills
3) headache
4) malaise
5) anorexia
6) abdominal pain
7) jaundice
8) generalized pruritus

Front 2

What are common physical exam findings?

Back 2

1) fever
2) scleral icterus
3) jaundice
4) hepatomegaly and tender

Front 3

What are common lab findings?

Back 3

1) increase lymphocytes
2) very elevated ALT and AST

Front 4

What genus is HBV in? family?

Back 4

1) orthohepadnavirus
2) hepadnaviridae

Front 5

What the genomic and structural characteristics of HBV?

Back 5

It is a double shelled double-stranded incomplete DNA virus

Front 6

Does it have the smallest viral genome?

Back 6

yes which limits its ability to mutate

Front 7

What is the structure of the DNA?

Back 7

circular partly double and partly single stranded with a short 5' RNA oligonucleotide

Front 8

Does HBV have an envelope? How many structural proteins does the genome have? What are the ones found in the envelope?

Back 8

1) yes
2) 5
3) HBsAg-S, HBsAg-M, HBsAg-L

Front 9

What is the function of HBsAg-S?

Back 9

main componet of envelope and is important in virion assembly

Front 10

Which protein is essential for infection?

Back 10

HBsAg-L

Front 11

What is type of capsid does it have? what protein is composed of? what else is in capsid besides DNA

Back 11

icosahedral composed entirely of HBcAg.

Pol protein

Front 12

What is the HBeAg?

Back 12

it is a processed form of core protein (HBcAg) that is secreted from infected cells into blood. Note it is not part of virion

Front 13

What are most of the empty spherical particles found in the blood composed of?

Back 13

HBsAg-S

Front 14

A person that has had a prior vaccination to HBV will have antibodies to what proteins?

Back 14

anti-HBs

Front 15

A person with prior acute resolved HBV will have which antibodies?

Back 15

anti-HBs, anti-HBc, anti-HBe Note Naths book does not include anti-HBe

Front 16

A serum sample shows presence of HBsAg, anti-HBc and HBeAg what is the diagnosis, acute or chronic infection?

Back 16

either

Front 17

A serum sample shows presence of HBsAg, anti-HBc and Anti-HBe what is the diagnosis?

Back 17

late stage chronic or asymptomatic carrier

Front 18

what antibody is present in past and present infection, including all stages?

Back 18

AntiHBc

Front 19

Why does acute hepatitis result?

Back 19

destruction of hepatocytes by CTL cells

Front 20

In individuals that develop acute or chronic infection that does not resolve, they lack what antibody and what viral protein will be found in their blood?

Back 20

HBs IgG is absent in some people and they have a predisposition to develop acute or chronic infection. When anti-HBs is absent the HBsAg protein is present

Front 21

When and how is the diagnosis for chronic HBV infection made?

Back 21

after 6 months if HBsAg is still present

Front 22

In chronic hepatitis why do aminotransferase levels fluctuate?

Back 22

because the virus has sporadic episodes of activity where it causes hepatocyte death

Front 23

HBV infection is associated with liver cancer. What are three ways HBV induces cancer?

Back 23

1) high turnover rate of hepocytes
2) HBV X protein can induce overexpression of host cell cycle progression
3) insertion of HBV DNA into host DNA

Front 24

Is HBV like retroviruses in that it has to insert into the host genome?

Back 24

no it typically exists as an episomal plasmid

Front 25

Is there a vaccine available?

Back 25

yes

Front 26

Which antigen appears first in blood? Second?

Back 26

1) HBs
2) HBe

Front 27

under electron microscope 3 different structures are identified. What are they?

Back 27

1) large round one have lipid envelope and are infectious
2) small nucleocapsid core of HBs
3) filamentous particles of HBs

Front 28

What is the primary component of the vaccine?

Back 28

HBs

Front 29

what is the most common mode of transmission in the US?

Back 29

sexual contact

Front 30

What is the incubation period?

Back 30

45-210 days for jaundice

Front 31

when does viremia occur?

Back 31

after entry

Front 32

A person presents at 2 weeks what markers will be present?

Back 32

only HBs this can be measured up to 12 weeks if acute

Front 33

What does the presence of antiHBs indicate?

Back 33

usually means erradication of acute infection

Front 34

When are DNA, HBeAg, or polymerase detected?

Back 34

transiently shortly after HBs

Front 35

When does IgM HBcAb appear in serum?

Back 35

about 6 weeks and is no longer present at 6 months

Front 36

What antibody persists and is an indicator of past infection?

Back 36

IgG HBcAb

Front 37

Acute infection can be made by the presence of what antibody?

Back 37

IgM HBcAb

Front 38

What does a test positive for HBsAg but negative for IgM HBcAb indicate?

Back 38

chronic infection of longer than 6 months

Front 39

Higher levels of what antigen indicate a greater infectivity?

Back 39

HBeAg

Front 40

When HDV is also present what results?

Back 40

fulminant liver

Front 41

How are acute and chronic hep B treated?

Back 41

1) nothing for acute
2) chronic treated with interferon alpha, lamivudine or adefovir