Micro - Virology (Hepatitis)

Question 1

What are the different Hepatitis viruses? What kinds of viruses (i.e., genome & name) is each?

Answer 1

(1) HAV - RNA picornavirus (2) HBV - DNA hepadnavirus (3) HCV - RNA flavivirus (4) HDV - RNA delta virus (5) HEV - RNA hepevirus

Question 2

What are the signs and symptoms of all hepatitis viruses?

Answer 2

Episodes of fever, jaundice, elevated ALT and AST

Question 3

How is HAV transmitted? What other hepatitis virus is transmitted this way?

Answer 3

Fecal-oral; HEV (fecal-oral, especially with waterborne epidemics); Think: “the vowels hit your bowels”

Question 4

How is HBV transmitted? What other hepatitis virus is transmitted this way?

Answer 4

Parenteral, sexual, maternal-fetal; HDV

Question 5

How is HCV transmitted?

Answer 5

Primary blood, IVDU, post-transfusion

Question 6

How is HDV transmitted? What other hepatitis virus is transmitted this way?

Answer 6

Parenteral, sexual, maternal-fetal; HBV

Question 7

How is HEV transmitted? What other hepatitis virus is transmitted this way? In what context is HEV especially transmitted?

Answer 7

Fecal-oral; HAV; Especially with waterborne epidemics; Think: “the vowels hit your bowels”

Question 8

Which hepatitis viruses are associated with carriers? Which are not?

Answer 8

CARRIERS: HBV, HCV, HDV; NON-CARRIERS: HAV, HEV

Question 9

What is the incubation period of HAV? What other hepatitis virus(es) share(s) this incubation period?

Answer 9

Short (weeks); HEV (also HDV superinfection)

Question 10

What is the incubation period of HBV? What other hepatitis virus(es) share(s) this incubation period?

Answer 10

Long (months); HCV (also HDV co-infection)

Question 11

What are the incubation periods of HDV, and in what contexts?

Answer 11

Superinfection (HDV after HBV) - Short; Co-infection (HDV with HBV) - Long

Question 12

What is the incubation period of HCV? What other hepatitis virus(es) share(s) this incubation period?

Answer 12

Long; HBV (also HDV co-infection)

Question 13

What is the incubation period of HEV? What other hepatitis virus(es) share(s) this incubation period?

Answer 13

Short; HAV (also HDV superinfection)

Question 14

What is the difference between HDV superinfection and co-infection?

Answer 14

Superinfection - short incubation period (Infection with HDV after developing chronic HBV); Co-infection - long incubation period (Acute infection of both HBV and HDV)

Question 15

Which hepatitis viruses pose an increased risk for Hepatocellular carcinoma? Which do not?

Answer 15

HCC RISK - HBV, HCV, HDV; NO HCC RISK - HAV, HEV

Question 16

How does HBV lead to increased HCC risk?

Answer 16

Integrates into host genome, acts as oncogene

Question 17

How does HCV lead to increased HCC risk?

Answer 17

From chronic inflammation

Question 18

Why are HAV and HEV able to have fecal-oral transmission?

Answer 18

Naked viruses do not rely on an envelope so they are not destroyed by the gut

Question 19

Describe how HBV creates its viral proteins.

Answer 19

In HBV, the DNA polymerase has both DNA- and RNA-dependent activities. Upon entry into the nucleus, the polymerase functions to complete the partial dsDNA. The host RNA polymerase transcribes mRNA from viral DNA to make viral proteins. The DNA polymerase then reverse transcribes viral RNA to DNA, which helps form new particles.

Question 20

What are 3 important characteristics to note about HAV?

Answer 20

(1) Asymptomatic (usually) (2) Acute (i.e., short incubation period) (3) Alone (no carriers); Think: “3 A’s for HAV”

Question 21

What are 2 important characteristics to note about HDV?

Answer 21

(1) Defective virus (2) Dependent on HBV; “Think: 2 D’s for HDV”

Question 22

What is the outcome of superinfection of HDV?

Answer 22

Superinfection –> decreased (i.e., worse) prognosis

Question 23

What are 3 important characteristics to note about HEV?

Answer 23

(1) Enteric (2) Expectant mothers (3) Epidemic; Think: “3 E’s for HEV”

Question 24

In what patient population does HEV have a high mortality?

Answer 24

High mortality in pregnant women

Question 25

What serological marker is best to detect active hepatitis A?

Answer 25

Anti-HAV (IgM antibody to HAV)

Question 26

What does Anti-HAV (IgG) indicate?

Answer 26

IgG antibody indicates prior HAV infection and/or prior vaccination

Question 27

Which Anti-HAV (IgM or IgG) protects against reinfection?

Answer 27

Anti-HAV (IgG)

Question 28

What is HBsAg, and what does it indicate?

Answer 28

Antigen found on surface of HBV; indicates hepatitis B infection

Question 29

What is Anti-HBs, and what does it indicate?

Answer 29

Antibody to HBsAg; indicates immunity to hepatitis B

Question 30

What is Anti-HBc? What do the IgM versus IgM versions of Anti-HBc indicate?

Answer 30

Antibody to HBcAg; IgM = acute/recent infection; IgG = prior exposure or chronic infection

Question 31

What is Anti-HBc?

Answer 31

Antibody to HBcAg

Question 32

Again, what is Anti-HBc? When is it positive?

Answer 32

Antibody to HBcAg; Positive during window period

Question 33

What is HBeAg? What does it indicate?

Answer 33

A second, different antigenic determinant in the HBV core (in addition to HBcAg); HBeAg indicates active viral replication and therefore high transmissibility

Question 34

What is Anti-HBe, and what does it indicate?

Answer 34

Antibody to e antigen; indicates low transmissibility

Question 35

Draw the hepatitis virus particle, labeling the following: (1) DNA polymerase (2) DNA genome (3) Core (HBcAg) (4) Coat protein (HBsAg) (5) its approximate size.

Answer 35

See p. 163 in First Aid (figure on left)

Question 36

Draw the hepatitis virus particle, labeling the following: (1) DNA polymerase (2) DNA genome (3) Core (HBcAg) (4) Coat protein (HBsAg) (5) its approximate size.

Answer 36

See p. 163 in First Aid

Question 37

What is the relation between ALT and AST in viral versus alcoholic hepatitis?

Answer 37

In viral hepatitis, ALT > AST; In alcoholic hepatitis, AST > ALT.

Question 38

What are the antigens associated with hepatitis virus? What are the associated antibodies?

Answer 38

SECES: SE are antigens, CES are antibodies

Question 39

In acute HBV, what serological markers are used for detection?

Answer 39

(1) HBsAg (2) HBeAg (3) Anti-HBc IgM

Question 40

Diagram the following hepatitis virus serological markers on a graph of months after exposure (x) versus titer (y): (1) HBeAg (2) HBsAg (3) Window period (4) Anti-HBe (5) Anti-HBs (6) Anti-HBc.

Answer 40

See p. 163 in First Aid (bottom graph)

Question 41

In the window period of hepatitis infection, what serological markers are used for detection?

Answer 41

(1) Anti-HBe (2) Anti-HBc IgM

Question 42

In chronic HBV (high infectivity), what serological markers are used for detection?

Answer 42

(1) HBsAg (2) HBeAg (3) Anti-HBc IgG

Question 43

In recovery from hepatitis infection, what serological markers are used for detection?

Answer 43

(1) Anti-HBs (2) Anti-HBe (3) Anti-HBc IgG

Question 44

Once a patient is immunized from hepatitis infection, what serological markers are used for detection?

Answer 44

Anti-HBs

Question 45

In chronic HBV (low infectivity), what serological markers are used for detection?

Answer 45

(1) HBsAg (2) Anti-HBe (3) Anti-HBc IgG