HIV

Question 1

What is the main route of transmission of HIV?

Answer 1

Sexual intercourse

Question 2

What is the 90/90/90 goal?

Answer 2

Worldwide goal by 2020:
- 90% of people living with HIV to be aware that they have it
- 90% of them to access antiretroviral therapy
- 90% of them, we want to be undetectable (viral suppression).
UK has reached this goal.
By 2030, we want to eliminate all HIV.

Question 3

What is PrEP? When can it be used?

Answer 3

Pre-exposure prophylaxis of HIV - emtricitabine and tenofovir - take once a day or on demand (if you know you’re going to have risky sex and for 2 days after) pre exposure prophylaxis (taking antiretroviral before sex to avoid getting HIV = very effective) = 86% risk reduction in contracting HIV, condoms give 80% risk reduction.

Question 4

What is PEP? When can it be used?

Answer 4

Post-exposure prophylaxis

• needle stick evidence on ward, given treatment after the injury
• not based on many studies as it is not ethical
• 28 days of treatment and need to start within 72 hours

Question 5

Is there any vaccine for HIV?

Answer 5

No

Question 6

What does U=U mean in HIV?

Answer 6

Undetectable = untransmissible

Question 7

What 2 things do we look for when testing for HIV?

What do these numbers mean?

• 200-500 T cells/mm3
• <200 T cell/mm3

Answer 7

CD4 count: immune system function
Viral load: amount of HIV in the blood.

• *200-500 T cells/mm3**
• Swollen lymph nodes
• Hairy leukoplakia (white patch on tongue caused by EBV)
• Oral candidiasis (yeast infection)
• <350 high mortality
• <350 in first test = late diagnosed HIV
• *< 200 T cells/mm3**
• Immune system severely compromised
• HIV → AIDS
• AIDS: persistent fever, fatigue, weight loss
• HIV count in blood increases

Question 8

How do we diagnose HIV?

Answer 8

Simple blood test

• Antibody/antigen test is recommended first line
• antibody test
• RNA/DNA test screening for copies of viral RNA in DNA

Question 9

What is the current treatment for HIV?

Answer 9

No cure but we can help reduce transmission and improve QOL

Two nucleoside reverse transcriptase inhibitors (NRTIs)
A third agent, typically one of:
Ritonavir-boosted protease inhibitor (PI/r)
Non-nucleoside reverse transcriptase inhibitor (NNRTI)
Integrase inhibitor (INI)

Example: 2NRTI + 1NNRTI or 2NRTI + 1 PI

Question 10

In terms of HIV sexual transmission, is vaginal or anal sex more likely to transmit HIV and are women or men more likely to spread it?

Answer 10

Anal sex is more likely to spread HIV
Heterosexual relationships are the biggest spreader
Male to female are more likely to spread than female to male

Question 11

Apart from sexual intercourse, what other ways can HIV spread? How have we reduced these risks?

Answer 11

Vertical transmission from mother to baby - screening for HIV in pregnancy and treating mother if infected
Blood - shared needles or re-used needles - needle exchange programme and education, screening blood products for HIV.

Question 12

Although anyone can be at risk of contracting HIV, who are the people most at risk?

Answer 12

Men who have sex with men (MSM)
Female sexual contacts of MSM
Trans women
Black Africans
Those from a country with high diagnosed seroprevalence
Those with sexual contact with anyone from a country with high seroprevalence
Those with a mother with HIV who have not themselves been tested
Those who use injectable drugs
Sex workers
Prisoners

Question 13

What are the 4 phases of HIV infection?

Answer 13

1. Acute primary infection: Transient immunosuppression and fall in CD4 count followed by a gradual rise and acute rise in viral load and then fall to ‘set point’. Primary infection occurs 2-4 weeks after exposure usually but can be months. There is an abrupt onset of non-specific symptoms such a flu-like symptoms
2. Asymptomatic phase/latency: They then enter a long asymptomatic phase which can last an average of 8 years where there is a progressive loss of CD4+ T cells resulting in poor immunity. These patients are still infectious with HIV. The only sign is usually lymphadenopathy in groin, axilla or neck.
3. Early symptomatic phase: Developing symptoms such as oral candida, cervical dysplasia, recurrent shingles etc.
4. AIDS: Presentation of HIV related illnesses CD4 <200. Normally we see jeroveci pneumoniae (43%) can also see HIV dementia, TB, wasting, kaposi’s sarcoma, anal or cervical warts.

Question 14

Why is it important to know that HIV has a latency period?

Answer 14

people are asymptomatic and still spreading the virus

Question 15

What are 3 respiratory conditions we commonly see in AIDS patients?

Answer 15

• bacterial (often pneumococcal) pneumonia
• TB
• Pneumocystis jiroveci pneumonia (PCP)

Question 16

Anyone presenting with TB should have what test done?

Answer 16

HIV test

Question 17

What neoplasms can be caused by HIV infection?

Answer 17

Lymphoma - late in HIV disease
Kaposi’s sarcoma
Molluscum contagiosum on face
Chronic HSV infection

Question 18

In the early acute infection with HIV, patients might present with certain symptoms, what are some examples?

Answer 18

Fever
Lymphadenopathy
Sore throat
Oral ulcers
Myalgia
Malaise
Diarrhoea
Rash
Headache

Question 19

When a patients CD4 count falls below what point are they said to have AIDs?

Answer 19

<200 T cells/mm3

Question 20

Once on treatment for HIV, what are the goals for viral load and CD4 count?

Answer 20

The aim is to reduce viral load to <50 copies per mil and increase the CD4 count

Question 21

Prognosis for HIV?

Answer 21

Patients who are diagnosed early and initiated on effective ART with suppression of viral load can expect life-expectancy equivalent to the general population.

Question 22

Describe the immunopathogenesis of HIV

Answer 22

1. HIV infects CD4+ helper T cells, macrophages and dendritic cells
2. Widespread seeding of lymphoid tissue occurs following the infection
3. HIV specific CD8+ cytotoxic T cells initially control the disease
4. Eventually HIV escaped the immune control through antigenic mutation
5. Viral load rapidly increases and CD4+ count decreases

Question 23

There are 2 types of HIV, HIV-1 and HIV-2, which is most common?

Answer 23

HIV-1

Question 24

What are the 3 ways which HIV can be spread from mother to baby?

Answer 24

• In utero through transplacenta
• Intra partum - exposure to maternal blood during delivery
• Breast feeding

Question 25

What can we offer to adolescents in Africa with HIV?

Answer 25

• HIV testing and counselling
• Link to HIV care
• Adherence support to ART
• HIV prevention and sexual reproductive health
• Rapid testing of oral fluid for HIV antibody

Question 26

Preventing HIV transmission

Answer 26

• Consistent condom use (80-90%)
• Male circumcision (60% reduction) as it removes a lot of the HIV transmissible cells
• Treating STI’s (genital ulcers and HSV infection increases transmission risk)
• Needle and syringe exchange for IVDUs
• Post-exposure prophylaxis
• Treatment as prevention (TasP) - 96% reduction
• Pre-exposure prophylaxis (PreP)

Question 27

Why is it difficult to manufacture a vaccine for HIV?

Answer 27

HIV-1 is highly variable so an effective vaccine would need to provide protection against the mulitple variants of HIV present in each infected person and HIV diversity is increasing over time.
A successful vaccine would need to provide protection against different routes of HIV acquisition