Blood Borne Viruses

Question 1

Hepatitis B consequences if left untreated

Answer 1

• Liver cirrhosis in 10% of cases

- Hepatocellular carcinoma

Question 2

Hepatitis C consequences if left untreated

Answer 2

• Liver cirrhosis in 80% of cases

- Hepatocellular carcinoma

Question 3

Percentage of the global population with Hep B and Hep C

Answer 3

5-8%

3%

Question 4

Hepatitis A: symptoms, transmission, incubation, chronic illness?

Answer 4

• Nausea, vomiting, jaundice
• Faeco oral
• 2 to 6 weeks
• Does not develop into chronic illness

Question 5

Hepatitis B: symptoms, transmission, incubation, chronic illness?

Answer 5

• Jaundice, fatigue, abdominal pain, anorexia/nausea/vomiting, anthralgia (pain in joint)
• blood, sex, vertical
• 6 weeks to 6 months
• Chronic illness may develop

Question 6

Hepatitis C: symptoms, transmission, incubation, chronic illness?

Answer 6

• high temperature, tiredness, loss of appetite, nausea, vomiting, may not have symptoms
• Blood, sex
• 6 to 12 weeks
• Chronic illness may develop

Question 7

Hepatitis D: symptoms, transmission, incubation, chronic illness?

Answer 7

• Can only propagate in the presence of the hepatitis B virus
• Blood, sex, vertical
• 6 weeks to 6 months
• Chronic illness will only develop with Hep B

Question 8

Hepatitis E: symptoms, transmission, incubation, chronic illness?

Answer 8

• Nausea, vomiting, jaundice
• Faeco oral
• 2 to 6 weeks
• Chronic illness is uncommon but possible

Question 9

What type of virus is Hepatitis B?

Answer 9

DNA, double stranded, enveloped

Question 10

What type of virus is Hepatitis C?

Answer 10

RNA, single stranded, positive strand, enveloped, icosahedral

Question 11

What type of virus is Hepatitis E?

Answer 11

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

Question 12

What type of virus is Hepatitis A?

Answer 12

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

Question 13

Production and excretion of bilirubin

Answer 13

• Haemoglobin is broken down into bilirubin by the reticuloendothelial system
• Bilirubin travels in the bloodstream, attached to albumin
• Bilirubin is broken down into conjugated bilirubin in the liver, by UDP glucuronyl transferase
• Conjugated bilirubin is either excreted in urine or transported in bile to the small intestines
• It is then excreted in faeces (Viral hepatitis slide 10)

Question 14

Types of jaundice

Answer 14

Prehepatic and cholestatis (intrahepatic, extrahepatic)

Question 15

Liver function tests

Answer 15

• Bilirubin
• Liver transaminases (Alanine transaminase, aspartate aminotransferase) HEPATOCYTE DAMAGE
• Alkaline phosphatase BILIARY TRACT CELL DAMAGE
• Albumin (synthesised in the liver)
• Tests of coagulation (clotting factors are synthesised in liver)

Question 16

How is hepatitis B most commonly transmitted?

Answer 16

Vertical transmission, 75% globally

• Sexual contact
• IV drug users
• Close household contacts
• Needlestick injuries

Question 17

Hepatitis B serology types

Answer 17

• HBsAg and HBsAb
• HBeAg and HBeAb
• HBcAg (cannot detect in blood, only in liver) and HBcAb (IgM and IgG)
• HBV DNA (PCR)

Question 18

Order of appearance of Hepatitis B serology

Answer 18

1) Surface antigen - rise in ALT
2) Followed by e-antigen - highly infectious
3) Core antibody (IgM)
4) Followed by e-antibody - heralds disappearance of e-antigen and infectivity
5) Surface antibody - clearance of virus
6) Core antibody (IgG) - persists for life

Question 19

Definition of chronic Hep B infection

Answer 19

Persistence of HBsAg after 6 months

• Becomes chronic in <10% if infected as an adult
• 90% if infected in infancy

Question 20

Treatment for Hep B

Answer 20

• No cure as it integrates into host genome
• Life long anti virals
• Not required for everyone (low VL, normal LFTs, no liver damage)

Question 21

Vaccination for Hep B

Answer 21

• Genetically engineered surface antigen
• 3 doses, boosters if required
• Produces surface antibody response ( >10 adequate, >100 long term protection)

Question 22

Who is most at risk of acquiring Hep C?

Answer 22

Intravenous drug users, >90% of those with Hep C in the UK

• Infants born to HCV+ mothers
• Sexual contact (higher if HIV co infected)
• Blood transfusions prior to 1991
• Needlestick injuries

Question 23

What percentage of those infected with Hep C will develop the chronic disease?

Answer 23

80%
Of those some will develop chronic liver disease/cirrhosis, resulting in:
- Decompensated liver disease
- Hepatocellular carcinoma
- Transplant
- Death

Question 24

Symptoms of Hep C?

Answer 24

80% will have no symptoms
The rest:
- Fatigue
- Anorexia
- Nausea
- Abdominal pain

Question 25

Blood tests to diagnose Hep C

Answer 25

- Anti Hep C antibody - Remains positive life long, even after clearance, not protective - Viral PCR

Question 26

Treatment for Hep C

Answer 26

- Can be cured - Directly acting antiviral drug combo - 8 to 12 weeks - 90% chance of cure - No vaccine

Question 27

Risk of transmission of HIV, Hep C and Hep B from needlestick injury

Answer 27

HIV - 1/300 (much lower if patient is on ARVs or VL is indetectable) Hep C - 1/30 Hep B - 1/3 (much lower if recipient has been vaccinated)