HIV

Question 1

What is the structure of the HIV virus?

Answer 1

Genome is a ssRNA virus with lipid membrane

Contains reverse transcriptase and integrases.

Question 2

What cell does it target?

Answer 2

T Helper cells

macrohages and monocyets

Question 3

Name and describe the stages of HIV infection.

Answer 3

Primary infection or seroversion- first 1-3 months
Latent infection (while host immunity lowers viral loads and CD4 count returns to near normal levels)
Symtomatic infection 350cells per microliter (CD4)
AIDS less than 200 cells per microlitre (CD4)

Question 4

How do we treat HIV and who gets treatment?

Answer 4

Anti-retrovirals (target binding and fusion, reverse transcriptase, integrate or the viral maturation and spread phase).

Every body with HIV should be treated regardless of CD4 count.

Some work on a vaccine.

Question 5

Which groups of people are most likely to develop HIV?

Answer 5

Globally heterosexuals (women more than men)
UK MSM

Question 6

What is the chance of HIV transmission from a needle stick injury on a treated low viral load HIV Patient?

Answer 6

1/333

Question 7

What are the big practice interventions we can make to prevent spread of HIV?

Answer 7

Partner tracing
Post exposure prophylaxis
Condom use
Antiretrovirals in HIV patients

Question 8

What are the initial signs of HIV infection?

Answer 8

Non specific flu like symptoms

Question 9

What cancer is associated with HIV?

Answer 9

Kaposi Sarcoma

Question 10

What oral infection may lead you to think of HIV testing?

Answer 10

Thrush

Question 11

What is PCP and what might it indicate.

Answer 11

Pneumocystitis pneumonia associated with HIV

Question 12

Someone who has had coldsores in the past but very infrequently presents suddenly having had 6 in 6 months, what might you suspect?

Answer 12

HIV often results in reactivation of latent viruses

Question 13

Other than viruses what other microbes does HIV particularly present with?

Answer 13

Yeast, Protozoa and Moulds.

Question 14

Most HIV patients live a long life with chronic infection so why do some people die?

Answer 14

Late diagnosis

Question 15

How many cases are there of HIV in the UK?

Answer 15

103,000 67% of which are men

Question 16

How does UHL perform HIV tests?

Answer 16

Opt out basis as rate is 3.8/1000

Question 17

57% of HIV in the UK is amongst the black african population, but what is the gender split in this group?

Answer 17

1/56 men

1/22 women

Question 18

Why could HIV be seen to be more serious in heterosexuals in that it carries a higher mortality rate?

Answer 18

> 50% are diagnosed late

Question 19

What percentage of people with HIV in the UK don’t know?

Answer 19

17%

Question 20

How does HIV effect the cell?

Answer 20

Replicates in the cell, destroys the cell, causes inflammation and then spreads.

Question 21

How does HIV infect cells?

Answer 21

Free Virus binds and fuses CD4 molecules and one other co-receptor (CCR5 or CXCR4).
Virus penetrates the cell membrane and empties its content. The ssRNA is then reverse transcribed to DNA. The DNA is then integrated into hosts nuclear genome by integrate. The host cell transcribes and translates microbial proteins. Viral RNA assemble and new immature viruses bud off.

Question 22

How is HIV transmitted?

Answer 22

Contact with infected bodily fluids and mucous tissue/ blood or skin breaks.

Sexual contact, transfusions, needles and perinatal.

Question 23

What factors effect transmission?

Answer 23

Exposure type
Viral load
Condom usage
Breaks in skin of mucousa

Question 24

What is the most risky activity for HIV transmission?

Answer 24

Receptive Anal Sex

Question 25

Whats the risk in blood transfusions?

Answer 25

90-100%

Question 26

How can we diagnose HIV?

Answer 26

Blood test - serology (antigens and antibody), shows up at 4 weeks and results on the same day but false negatives possible.

Blood test PCR is highly sensitive even in early infection but is low and expensive so is not used as an initial HIV test.

Rapid tests are low cost and results in under an hour- look for HIV antibody in blood or saliva. Available as a postal test. False negatives can occur and thus need confirmation with serology.

Question 27

What are the aims of HIV treatment?

Answer 27

Undetectable viral load 
Normal CD4 count 
Reduce inflammation 
Reduce transmission risk 
Good quality of life
Normal life expectancy

Question 28

Who should be tested? (Hint split down to body systems)

Answer 28

Everyone if rate is >2/1000
Resp px: bacterial pneumonia or TB
Neuro px: meningitis/dementia
Derm px: severe psoriasis, reccurent shingles
Gastro px: chronic diarrhoea, weight loss
Haem px: anything unexplained. 
Onco px: lymphoma, anal canncer
Gynae px: CIN
GU px: Any STI, Hep B or C

Question 29

Give some examples of specific HIV treatments and their mechanisms of action.

Answer 29

Nucleotide revers transcriptase inhibitor - Emtricibine
Non-nucleotide reverse transcriptase inhibitor: Efavirenz
Protease inhibitor -Darunavir
Integrase inhibitor- Dolutegravir
(note one of a NRTI should be prescribed with one other)

Question 30

Give some examples of specific HIV treatments and their mechanisms of action.

Answer 30

Nucleotide revers transcriptase inhibitor - Emtricibine
Non-nucleotide reverse transcriptase inhibitor: Efavirenz
Protease inhibitor -Darunavir
Integrase inhibitor- Dolutegravir
CCR5 inhibitor Maraviroc
(note one of a NRTI should be prescribed with one other)

Question 31

Why do we give 3 ARV?

Answer 31

Millions of replications per cell in a day so lots of mutations meaning drug resistance to mono therapy can develop with in days. We need patients to take the trio consistently to avoid resistance.

Question 32

List strategies in treating and lowering HIV prevelence.

Answer 32

Condom use 
Prevent vertical transmission 
ARV treatment as a preventative 
Medical circumcision 
Post and pre exposure prophylaxis

Question 33

Name the ethical dilemmas in HIV.

Answer 33

Psychological impact of the diagnosis
Dealing with stigma
Patient confidentiality - who else is at risk?- children, partners and HCW

Question 34

How is post exposure prophylaxis given?

Answer 34

risk assessed
3x daily ARV for 28 days
Start with in 72 hrs (ASAP)
HIV baseline and test again at 1 and 3 months