Hepatitis B and C

Question 1

describe the structure of the hepatitis B virus

Answer 1

• 3 different types of particle found
• largest particle is the Dane particle - infectious particle which comprises the complete virion
• spherical particles and filamentous forms - comprised of surplus HBsAg and are non-infective

Dane particle

Question 2

what are the modes of transmission of hepatitis B?

7

Answer 2

• IV drug users
• sexually active
• children of immigrants from disease-endemic areas
• sexual / household contacts of infected people
• infants born to infected people
• healthcare workers
• haemodialysis patients

Question 3

describe the clinical course of disease for hepatitis B for a normal recovery

6

Answer 3

• incubation period 2-3 months
• mostly no symptoms (flu-like illness, possibly yellow tone of skin or sclera)
• HBsAg is the first viral marker and may appear before symptoms
• soluble HBeAg becomes detectable shortly after
• IgM develops approx. 2 weeks after appearance of HBsAg and disappears 6 months later, being gradually replaced by IgG
• clearance of antigens and creation of Anti-HBs within 6 months

Question 4

describe the clinical course of disease for hepatitis B for a chronic carriage

3

Answer 4

• incubation period 2-3 months
• mostly no symptoms (flu-like illness, possibly yellow tone to skin or sclera)
• HBsAg persists and no development of Anti-HBs

Question 4

what is chronic carriage of hepatitis B defined as?

Answer 4

persistence of HBsAg and failure to develop HBsAb more than 6 months after infection

Question 5

is there a vaccination for hepatitis B? if so, how is it produced and how many doses?

Answer 5

yes - hepatitis B surface antigen (HBsAg) absorbed on aluminium hydroxide adjuvant produced by recombinant DNA technology
* 3 doses: time zero, one month, six months

Question 6

is post exposure prophylaxis required for hepatitis B?

Answer 6

not required for those who have had a successful response to vaccine
* vaccine booster required if unresponsive to vaccine

Question 7

what is the treatment for hepatitis B?

Answer 7

• 7 anti-viral drugs for chronic hep B
• immunodulatory agents, oral nucleoside analogues, nucleotide analogues

Question 8

describe the structure of hepatitis C

2

Answer 8

• enveloped, single standed RNA
• variable HCV genome

Question 9

what are the modes of transmission for hepatitis C?

6

Answer 9

• IV drug use
• blod and blood products (transfusions, dialysis)
• organ and tissue transplantation
• sexual transmission
• vertical transmission (mother to child)
• occupational transmission

Question 10

describe the pattern of acute hep C infection with recovery

3

Answer 10

• incubation period is similar to hep B (2-3 months)
• elevated serum enzymes appear 4-12 weeks post exposure
• shortly after hep C virus is measureable

Question 11

describe the pattern of acute hep C infection with progression to chronic infection

Answer 11

• main problem with hep C infection is persistence
• after 6 months of persistence of HCV RNA within the blood, the infection is defined as chronic

Question 12

what is the treatment for hepatitis C?

Answer 12

• no vaccine available currently
• direct actign antiviral aents (DAAs) target HCV-encoded proteins that are essential for viral replication
• first generation protease inhibitors
• second generation protease inhibitors (beter efficacy, fewer drug interations, safer, more tollerant)