Session 6 - Blood Borne Viruses

Question 1

What is the structure of HIV?

Answer 1

Single stranded RNA retrovirus

Question 2

How does hIV attach to cells?

Answer 2

Using gp120 portion of the envelope gene product on HIV surface, binds to CD4 molecules

Question 3

How does HIV replicate?

Answer 3

Binds and fuses with the cell, penetrates and empties contents, using reverse transcriptase to convert RNA to DNA, integrates viral DNA into cell’s own DNA using integrase enzyme, viral DNA is read and long chains of proteins are made, sets of viral protein chains come together and are pushed out of cell, and mature to make a working virus

Question 4

How is HIV transmitted?

Answer 4

Contact of infected bodily fluids with mucosal tissue or blood or broken skin through sexual contact, blood transfusion, contaminated needles, vertical transmission

Question 5

What are 3 diagnostic tools to detect HIV?

Answer 5

Serology - detects antigens and antibodies in blood
PCR - detects viral nucleic acid
Rapid testing - picks up antibodies

Question 6

How are patients with HIV treated?

Answer 6

Anti-retro viral drugs regardless of CD4 to ensure an undetectable HIV viral load allowing CD4 count to recover, reduce general inflammation and transmission

Question 7

How does anti-retro viral drugs work, what are the 4 ways retroviral target to work?

Answer 7

Targeting the binding (CCR5-entry inhibitor), the enzymes responsible for incorporation of viral DNA into host DNA (integrase inhibitor), breaking down large proteins into smaller units (protease inhibitor)and reverse transcriptase

Question 8

What are 3 ARVs to giver?

Answer 8

Less chance to develop resistance

Question 9

What are 7 potential strategies to treat and reduce prevalence of HIV?

Answer 9

Increase condom usage
ARV treatment as prevention 
Wide spread testing 
Prevention of mother to child transmission 
PEP
PrEP
Male circumcision

Question 10

What is icteric sclera?

Answer 10

White of the eyes are elbow

Question 11

What are the 3 types of jaundice?

Answer 11

Pre hepatic
Intrahepatic
Extrahepatic

Question 12

What kind of jaundice does hepatitis cause?

Answer 12

Intrahepatic jaundice

Question 13

What does a raised ALT or AST mean?

Answer 13

There is hepatocytes damage and problem is intrahepatic

Question 14

What does a raised ALP mean?

Answer 14

Problem in biliary tract - extrahepatic

Question 15

What is the predominant transmission of hepatitis B?

Answer 15

Vertical

Question 16

What are the 5 main symptoms of hepatitis B?

Answer 16

Jaundice
Fatigue
Abdominal pain
Anorexia
Arthralgia

Question 17

What is the incubation period of hepatitis B?

Answer 17

Six weeks to 6 months

Question 18

What are the 2 tests for hepatitis B?

Answer 18

Serology and HBV DNA PCR test

Question 19

What are the 6 antibodies in Hepatitis B serology?

Answer 19

Surface antigen - HBsAg
E-antigen - HBeAg
Core antibody - IgM
E-antibody - HBeAb
Surface antibody - HBsAb
Core antibody - IgG

Question 20

What is chronic Hep B infection?

Answer 20

Persistence of HBsAg after 6 months

Question 21

How to treat Hep B infection?

Answer 21

Life long anti virals to suppress viral replication if no liver damage

Question 22

How does the vaccination for Hep B work?

Answer 22

It is a genetically engineered surface antigen and produces surface antibody response

Question 23

How many doses of Hep B vaccines?

Answer 23

3

Question 24

Who is at risk of Hep C?

Answer 24

People who inject drugs

Question 25

What are the symptoms of Hep C?

Answer 25

Most have none

Question 26

What are 2 ways to test for Hep C?

Answer 26

Serology - presence of anti Hep C antibody

PCR

Question 27

How to treat Hep C?

Answer 27

Directly acting anti viral drug combo for 8-12 weeks

Question 28

What is post exposure prophylaxis?

Answer 28

Early initiation of ARVs reduces dissemination and replication of HIV in tissue and bodily fluid