S8) Blood Borne Viruses – Hepatitis Flashcards Preview

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Flashcards in S8) Blood Borne Viruses – Hepatitis Deck (23)
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1

What is hepatitis?

Hepatitis is the inflammation of the liver due to cell injury or viruses (hepatotropic) which can cause collateral liver damage e.g. EBV, CMV, VZV

 

2

Outline Hepatitis B and C in terms of transmission, incubation and affirmation of chronic illness

3

Outine the viral structure of different types of hepatitis

- Hepatitis B: dsDNA, enveloped

- Hepatitis C: ssRNA, positive, enveloped, icosahedral 

 

4

Outline the production and excretion of bilirubin

5

Identify the different types of jaundice and their causes

- Prehepatic – caused by haemolysis 

Intrahepatic – caused by viral hepatitis, drugs, alcohol hepatitis, cirrhosis

Extrahepatic  caused by common duct stones and carcinoma

6

Identify some liver function tests (LFTs)

- Bilirubin

- Albumin

- ALT & AST

- Alkaline phosphatase (ALP)

- Coagulation tests – INR & PT

7

How can Hepatitis B be transmitted?

- Vertical transmission

- Sexual contact

- Contaminated needles (IVDU, HCW)

8

What are the symptoms of acute Hep B?

- Jaundice

- Fatigue

- Abdominal pain

- Anorexia / nausea / vomiting

- Arthralgia

9

What are the microbiological findings of Acute Hep B?

AST/ALT in 1000s

10

Describe the complications of Acute Hep B

- Up to 50% – no/vague symptoms & clear infection within 6 months

- <1% – fulminant hepatic failure

- <10% – becomes chronic (if adult)

- Up to 90% – becomes chronic (if infant)

11

Outline the 6 steps in Hepatitis B serology

⇒ Surface antigen, within 6 weeks (HBsAg)

⇒ Highly infectious e-antigen (HBeAg)

⇒ Core antibody appears first (IgM)

⇒ e-antibody appears, less infectious now (HBeAb)

⇒ Surface antibody appears last, clears virus (HBsAb)

⇒ Core antibody persists for life (IgG)

12

What is a chronic Hep B infection and what are its consequences?

A chronic Hep B infection is the persistence of HBsAg after 6 months:

- 25% chronic infection leads to cirrhosis

- ~5% will develop hepatocellular carcinoma

13

What is the treatment for chronic Hepatitis B?

NO CURE – integrates into host genome

- Life-long anti-virals required to suppress viral replication

- Not required for everyone e.g. "inactive" carrier (Low VL / normal LFTs / no liver damage)

14

Describe the composition and effective response of the Hepatitis B vaccination 

- The vaccination consists of a genetically engineered surface antigen (3 doses + boosters if required)

- Produces surface antibody response:

I. >10 adequate

II. >100 long-term protection

15

What's the status (HBsAg, HBsAb, HBcAb) for Hepatitis B in terms of:

- Acute infection

- Cleared infection

- Chronic infection

- Vaccinated

16

Who is at risk of Hep C transmission?

- IVDU

- Sexual contact

- Infants born to HCV positive mothers 

- Blood transfusion prior to 1991

- HCW via needlestick injuries

17

Outline the disease progression of Hepatitis C

- ~80% become chronically infected

- Of these some will develop chronic liver disease/cirrhosis

18

What are the complications of chronic liver disease/cirrhosis due to a chronic Hepatitis C infection?

- Decompensated liver disease

- Hepatocellular carcinoma (primary liver cancer)

- Transplant

- Death

19

What are the symptoms of Hepatitis C?

- 80% have no symptoms (acute or chronic)

- 20% have vague symptoms:

I. Fatigue

II. Anorexia

III. Nausea

IV. Abdominal pain

20

Identify and describe the blood tests involved in Hepatitis C

Serology – anti-Hep C antibody as it remains positive throughout life, even after clearance/cure (not protective, can get reinfected)

- Viral PCR – if positive, confirms on-going / chronic infection

21

Discuss the treatment for Hepatitis C

- Cure/but no vaccine

- Directly acting antiviral drug combo:

I.  8-12 weeks

II.  >90% chance of cure

III. £20,000 - £60,000 per course

IV. Can get re-infected

22

Discuss the risk of transmission of HIV, Hep B and C from needlestick injury

- Hep B – 1/3 (much lower if recipient has been vaccinated)

- Hep C – 1/30

- HIV – 1/300 (much lower if patient is on ARVs / VL undetectable)

23

Distinguish between HIV, Hep B and Hep C in terms of:

- Acute infection

- Prevention

- Outcome of untreated infection

- Treatment