Infection - Viral Hepatitis

Question 1

What is hepatitis?

Answer 1

Inflammation of the liver due to replication of hepatitis viruses within hepatocytes resulting in their destruction

Question 2

What is the incubation period for hep B?

Answer 2

6 weeks to 6 months

Question 3

What is the incubation period for hep C?

Answer 3

6-12 weeks

Question 4

What is the viral structure of hep B?

Answer 4

DNA, doubled stranded, enveloped

Question 5

What is the viral structure of hep C?

Answer 5

RNA, single stranded, positive strand, non-enveloped icosahedral

Question 6

How is bilirubin produced and transported to the liver?

Answer 6

In red blood cells, haemoglobin is converted into bilirubin and excreted into the bloodstream. It attaches to albumin and is transported to the liver where UDP glucuronyl transferase converts it to conjugated bilirubin. This may be excreted in urine or enter the small intestine to be excreted in faeces.

Question 7

What are the three different types of jaundice?

Answer 7

• prehepatic
• intrahepatic cholestatic
• extrahepatic cholestatic

Question 8

What tests can be carried out to assess liver function?

Answer 8

• bilirubin
• liver transaminases
• alkaline phosphatase
• albumin
• tests of coagulation

Question 9

How is hep B transmitted/who is at risk?

Answer 9

• vertical transmission
• sexual contact
• injected drug users
• close household contacts
• healthcare workers via needle stick injuries

Question 10

What are the symptoms of acute hep B?

Answer 10

• jaundice
• fatigue
• abdominal pain
• anorexia/nausea/vomiting
• arthralgia

Question 11

Explain the sequence of antigens and antibodies present in a hep B infection

Answer 11

• first is HBsAg, the surface antigen
• next is HBeAg, the e-antigen which indicates that they are highly infectious
• the core antibody (IgM) is the first antibody to appear
• the e-antibody comes next, indicating disappearance of e-antigen and the infectivity of the patient
• surface antibody is the last antibody to appear, which indicates clearance of the virus/recovery
• core antibody IgG will be present for life

Question 12

Define a chronic hep B infection

Answer 12

Persistence of HBsAg after 6 months

Question 13

How is hep B treated?

Answer 13

There is no cure as it integrates into the host genome. Life-long antivirals can be given to suppress viral replication.

Question 14

What is the hep B vaccine?

Answer 14

It is a genetically engineered surface antigen which produces the surface antibody response. It is effective in most people, but requires 3 doses and boosters

Question 15

How is hep C transmitted/who is at risk?

Answer 15

• injected drug users
• sexual contact
• vertical transmission
• blood transfusion before 1991
• needlestick injuries

Question 16

Is hep C likely to be chronic?

Answer 16

Yes - 80% become chronically infected

Question 17

What are the possible complications of chronic liver disease/cirrhosis?

Answer 17

• decompensated liver disease
• hepatocellular carcinoma
• transplant
• death

Question 18

What are the symptoms of hep C?

Answer 18

• 80% have no symptoms

- 20% have vague symptoms of fatigue, anorexia, nausea, abdominal pain

Question 19

Is there a vaccine for hep C?

Answer 19

Nah

Question 20

How is hep C treated?

Answer 20

Directly acting antiviral drug combination for 8-12 weeks can cure, but can get re-infected