BBV

Question 1

What type of virus are HBV, HCV and HIV and to what family of viruses do they belong?

Answer 1

HBV - DNA virus - Hepadnavirus

HCV - RNA - Flavivirus

HIV - RNA - Retrovirus

Question 2

What are the 3 routes of transmission of BBV?

Answer 2

Sexual intercourse
Blood
Vertical

Question 3

What is the single important route of transmission for each of the viruses?

Answer 3

HBV - vertical

HCV - blood

HIV - sexual transmission

Question 4

Why is HBV virus dangerous for the fetus?

Answer 4

HBV e antigen crosses the placenta
Fetus immune system recognises e antigen as self antigen
No immune response
Leads to chronic infection

Question 5

What maternal factor effects the likelihood of the infant being infected with HBV?

Answer 5

If the mother has e antigen and surface antigen - 70-90% infants infected

If the mother has surface antigen only - <10% infected

Question 6

What does the HBsAg tell?

Answer 6

if the current infection is present

Question 7

What does the HBeAg tell?

Answer 7

How infective they are - high grade infection

Question 8

What does the Anti - HBsAg tell?

Answer 8

Shows immunity - natural or vaccine

Question 9

What are the two types of chronic HBV infection?

Answer 9

e antigen positive - high grade infection - high risk of vertical transmission - high risk of hepatitis, cirrhosis and hepatocellular carcinoma

e antigen negative - low grade infection - low risk of vertical transmission - low risk of hepatitis, cirrhosis and hepatocellular carcinoma

Question 10

What is the treatment for HBV?

Answer 10

lamivudine (used in the past but resistance develops)
tenovovir is now used to suppress the inection

interferon - to cure the infection (less successful)

transplantation

Question 11

Why would you want to determine the genotype of the Hepatitis C infection?

Answer 11

There are 6 genotypes, respond differently to treatment therefore need different length of treatment
Genotype 1 - 12 months
Genotype 3 - 6 months

Question 12

What medical treatment is available for Hepatitis C?

Answer 12

Ribavirin and interferon

Question 13

Hat test would you run to determine the response to treatment in HIV?

Answer 13

Viral load and CD4 count

Question 14

How would you test for HIV?

Answer 14

4th generation test - testing for both the antigen and the antibody

HIV antibody and p24

Question 15

How would you treat HIV?

Answer 15

Highly active antiretroviral therapy HAART

3 drugs from 3 classes
Nucleoside reverse transcriptase inhibitor
Non Nucleoside reverse transcriptase inhibitor
Proteinase inhibitor

Question 16

Name 3 ways that you can prevent mother to baby HIV infection.

Answer 16

1 - caesarian
2 - HAART mother and baby
3 - no breastfeeding

Question 17

Which BBVs are enveloped and how does that affect their survival?

Answer 17

Hep B, Hep C HIV are all enveloped
- they do not survive for long in the environment

Hep A is not enveloped - can survive for longer

Question 18

Why is it useful to enquire what genotype of Hep C is present?

Answer 18

Guides the duration of treatment

Type 1 is bad - 12 months of treatment

Type 3 is good - 6 months of treatment

Question 19

How does HIV present at the time of infection?

Answer 19

Glandular fever, lymphadenopathy, rash, fever

Question 20

How would you test for Hep C?

Answer 20

PCR

Question 21

Whats the appropriate treatment for pneumocystis jirovecii?

Answer 21

co-trimoxazole