Hep B & C Epidemiology and Dental Relevance

Question 1

What are the particles found in the blood of someone with hep B?

Answer 1

The largest particle known as the Dane particle comprises the complete virion (the infectious particle).

In addition to the Dane particle there are spherical particles and filamentous forms. They are comprised of surplus HBsAg and are non-infective.

Question 2

How many genotypes is there and which one is most frequent in North America, northern Europe and Africa?

Answer 2

10 genotypes
A

Question 3

What is the structure of the dane particle (hep intact virus)?

antigens and genetic material

Answer 3

Hep b surface antigen (HBs Ag)
Hep b core antigen (HBc Ag)
DNA (circular and partially double stranded)

Question 4

How long does HBV survive in dry blood?

What are the modes of transmission?

Answer 4

1 week or more

parenteral
sexual
perinatal

Question 5

Acute VS Chronic Hep B

who has the highest risk of chronic

Answer 5

Acute infection: can be asymptomatic or cause flu-like illness, jaundice. Antigens are cleared within 6 months
Chronic infection: persistence of HBsAg for >6 months, no development of anti-HBs

both have incubation period of 2-3 months

neonates have highest risk of chronic

Question 6

What are the HBV markers that can be tested for?

Answer 6

HBsAg
anti-HBc IgM/IgG
anti-HBs

Question 7

What core antibodies will be produced in response to Hepatitis B infection?

Answer 7

IgM core antibody will be produced first, with IgG core antibody taking over the role of IgM afterwards

Question 8

What are the advantages of the Hep B vaccination?

Answer 8

• Highly immunogenic
• No booster required if response is good
• Protection: good

Question 9

How is the Hep B vaccine given and how many doses?

Answer 9

Vaccine administration: intramuscular
Three doses: Time zero, one month and six months

Question 10

What is the Hep B vaccine made of?

how is it produced

Answer 10

hepatitis B surface antigen (HBsAg) adsorbed on aluminium hydroxide adjuvant
produced by recombinat DNA tech

Question 11

When should antibody test be done post immunisation?

Answer 11

2-4 months after course

Question 12

What is prohylaxis HBV for unvaccinated and vaccinated but non responder?

Answer 12

• Unvaccinated - HBIG x 1 and initiate hepatitis B vaccine series
• Vaccinated but non responder - HBIG x 1 and vaccine booster

HBIG (hepatasis B immuno globulin)

Question 13

What are the drugs used for treatment of chronic HB?

Answer 13

Antivirals (interferons, nucleoside/nucleotide analogues)

Question 14

What are the main drugs used for HBV?

Answer 14

nucleoside and nucleotide analogues

Question 15

What is the structure of Hep C?

how many genotypes and genetic material

Answer 15

Enveloped, single-stranded RNA virus, high genetic variability

1-6

Question 16

How long does HCV survive on inanimate surfaces?

how is it transmitted?

Answer 16

up to a week
via blood, organ/tissue transplant, sex, mother to child

Question 17

What is the incubation period of HCV?

Answer 17

Up to 26 weeks (mean incubation period is 6-12 weeks)

Question 18

What testing is available for HCV and how does it work?

Answer 18

Anti-HCV antibodies
HCV RNA (for active infection)
Viral load
Genotyping (type)

Question 19

What % of the acute HCV phase patients progress to chronic?

Answer 19

Acute infection often asymptomatic, high risk of progression to chronic infection (75%)

Question 20

What can chronic infection lead to?

% SVR

Answer 20

cirrhosis, liver failure, and hepatocellular carcinoma

Question 21

Is there a vaccine for HCV?

What treatment is avaliable?

Answer 21

no
Directly acting antiviral drugs (DAAs) have been used for treatment
SVR > 90%

Question 22

What is a SVR?

Answer 22

a sustained viral response (SVR), which equates to a cure
VERY HIGH in patients taking DAAs

Question 23

Which BBV has a vaccine?

Answer 23

HBV

Question 24

Which BBV has no PEP?

Answer 24

HCV

Question 25

Which BBV is the most infective?

Answer 25

HBV