11. HIV

Question 1

Infection with what pathogens is a patient with HIV more at risk of getting?

Answer 1

Reactivation of latent viral infections
Fungus infections - both yeast and mould
Protozoal parasite infections

Question 2

What race are a half of all heterosexuals in the UK with HIV?

Answer 2

Black African

Question 3

HIV is a retrovirus. What is a retrovirus?

Answer 3

SsRNA, once inside host cell uses reverse transcriptase to produce DNA from ssRNA, DNA is then incorporated into the host cell genome, and the cell starts producing the virus RNA and proteins

Question 4

What cells does HIV infect?

Answer 4

CD4 surface receptor so mainly T helper lymphocytes

Question 5

How is HIV transmitted?

Answer 5

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

Question 6

What happens to the CD4 count on primary HIV infection/seroconversion?

Answer 6

Temporary drop

Question 7

What happens to the CD4 count in latent HIV infection/stage I?

Answer 7

Returns to normal

Question 8

What happens to the CD4 count on symptomatic HIV infection/ stages II and III?

Answer 8

Drops down to below 350

Question 9

What happens to the CD4 count on severe HIV infection/AIDS/stage IV?

Answer 9

Drops to below 200 cells/microL

Question 10

Give an example of one condition assocaited with each stage of HIV?

Answer 10

Stage I - Oral thrush
II - Kaposi’s sarcoma
III - TB
IV - lymphoma

Question 11

Give 4 factors affecting HIV transmission

Answer 11

Type of exposure eg type of sexual act
Viral load in blood - transmission unlikely if there is an undetectable viral load
Condom use
Breaks in skin or mucosa - other STI leads to inflammation of genital tract, increasing risk of HIV transmission

Question 12

What antigen and antibody are detected in a serology testing for HIV? Any rules when testing?

Answer 12

HIV antigen - Ag
HIV antibody - Ab
Need to wait 4 weeks after infection for a positive result, get result on same day

Question 13

What does a PCR blood test for HIV detect? Any rules when using this testing?

Answer 13

HIV nucleic acid
Detects very early infection (few days) but expensive and results take up to a week. Used for follow-up/treatment response

Question 14

What do rapid HIV tests usually detect? What two bodily fluids can they test? What type of result may occur?

Answer 14

HIV antibody
Blood test or saliva
False positive, so all positive tests need confirming with a serology

Question 15

What HIV rate in the population is needed for everyone to be tested?

Answer 15

> 2/1000

Question 16

Name 4 indicators for testing for HIV

Answer 16

Resp - TB
Dermatome - recurrent shingles
Onc - lymphoma, anal cancer
Any STI/ Hep B/C

Question 17

What are the 6 aims of HIV treatment?

Answer 17

Undetectable HIV viral load
Reconstitute CD4 count
Reduce general inflammation
Reduce risk of transmission
Good quality of life
Normalise lifespan

Question 18

What 3 things happen when HIV replicated inside cells?

Answer 18

Destroys cell
Causes inflammation
Spreads to/ infects more cells

Question 19

How many anti-retrovirals do you give to a patient with HIV? Why?

Answer 19

3, as virus mutates every 2-3 rounds of replication, and there are millions of rounds of replication a day, so with 3 drugs it is harder to develop resistance.

Question 20

What 6 things can be used in a combination to treat and reduce the prevalence of HIV?

Answer 20

Increase condom usage
Prevention of mother-to-child transmission
Antiretroviral treatment as prevention
Medical circumcision
Post-exposure prophylaxis
Pre-exposure prophylaxis

Question 21

Name 3 types of antiretrovirals

Answer 21

Nucleoside reverse transcriptase inhibitor
Non-nucleoside reverse transcriptase inhibitor
Protease inhibitor
Integrate inhibitor