Blood bourne virues (BBV) Flashcards Preview

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Flashcards in Blood bourne virues (BBV) Deck (29):
1

What is a BBV?

A virus that has a viraemic phase that may be self limited (acute) or persistent (chronic)
They are enveloped and easily inactivated

2

Which three BBV are of main concern?

Hep B, Hep C, HIV

3

How are BBV's transmitted?

By blood and bodily fluids
Via mucus membranes or percutaneous

4

Where is Hep B prevalent?

Asia, Sub Saharan Africa
700,000 deaths /yr

5

How do we define acute and chronic Hep B?

Acute - most adults will overcome
Chronic - >6 months, may see chronic liver disease

6

What is the incubation period for Hep B?

60 - 90 days

7

What causes mortality in Hep B?

Hep B accounts for :
30% Liver cirrhosis
53% Hepatocellular cancer (HCC)

8

How do we diagnose Hep B?

Serological patterns:
Hep B surface antigen +ve = means currently infected
Hep B surface antibody +ve = means recovered

9

What is the management for acute Hep B?

No antivirals given
Counseling regarding transmission
Screen for other BBV and trace contacts

10

How do we manage chronic Hep B?

Give antiviral therapy - nucleoside analogues
Immuno-modulators

11

How do we prevent transmission of Heb B?

Screening - especially pregnant and at risk groups
Vaccine

12

What is Hep C?

+ve SS RNA, enveloped
Many different genotypes distributed geographically

13

Name 2 high risk areas?

Egypt and Bristol

14

What is the progression of Hep C?

Hep C
Acute infection (only 20% show symptoms)
Chronic infection (extrahepatic manifestations)
Chronic active Hep C
Cirrhosis ( can get HCC)

15

What causes burden in Hep C?

HCV accounts for :
27% liver cirrhosis
25% HCC

16

How do we manage acute Hep C?

Allow time for recovery
Treatment very effective

17

How do we manage chronic Hep C?

Asses liver function
Fibroscan ( increased stiffness = increased viral load)
Immunise against HAV and HBV
Antiviral therapy to clear virus and prevent progression

18

How can we prevent Hep C?

NO VACCINE

19

What is HIV?

retrovirus, enveloped ds RNA genome
Integrate into host cell chromosomes and can run off copies of virus regularly

20

What is the HIV related to?

HIV 1 - chimp virus
HIV 2 - sooty mangabey

21

How did the human HIV epidemic occur?

Result of exposure to blood during animal butchering and spread by urbanisation and travel

22

What population of people have the highest prevalence of HIV?

Gay men (MSM - men who sex with men)

23

What is vertical transmission?

HIV spread from mother to child

24

How do we diagnose HIV?

Sreening
Test risk groups

25

What does the HIV virus do?

Attacks lymphocytes and constantly mutates

26

What are the 4 main oral signs of HIV?

Rash - non specific, often with flu 2 - 6 weeks after infection
Oral candida
Karposi's Sarcoma - raised purple lesions, linked to HHV8
Oral hairy leukoplakia - white plaques along lateral tongue borders. Link to EBV

27

How do we manage HIV?

Counselling
Antiretroviral therapy (based on CD4 count and viral load)
There are drugs for all stages of the virus

28

What is combination therapy?

HAART - highly active anti-retroviral therapy
+vs: More potent, less drug resistance
-ves: More side effects

29

Out of Hep B, Hep C and HIV, which is the most risky for transmission?

HBV = 30-3%
HCV = 1-3%
HIV = 0.3%