hiv

Question 1

What is HIV?

Answer 1

Human immunodeficiency virus
Mutates readily- as reverse transcriptase doesn’t proof read

AIDS- acquired immunodeficiency syndrome

Question 2

How is HIV transmitted?

Answer 2

Sexual contact
Blood-blood contact
Infected blood products
In utero
Breast milk

Question 3

What are the types of HIV?

Answer 3

HIV 1- more common (3 main subtypes- M, N, O)
HIV 2- less easily transmitted/pathogenic (stays confined to West Africa)

Question 4

What is the structure of HIV?

Answer 4

Envelope glycoproteins
Lipids from host cell
Nuclear capsid containing single stranded RNA
Reverse transcriptase
Protease

Question 5

How does HIV infect?

Answer 5

1. gp120 binds to CD4 positive cells and CCR5/CXCR4 which triggers internalisation of virus into cell

2. RNA is reverse transcribed into DNA which is incorporated into genome

3. Protective environment and new copies of virus (budding to infect other cells)

Pts w CCR5 mutations are resistant to HIV

Question 6

How does the virus vary during infection?

Answer 6

EARLY
-targets CCD5
-macrophage tropic, low cytopathic, more transmissible

LATE
-targets CXCR4
-T-cell tropic, high cytopathic, less transmissible

Question 7

What are some oral manifestations of HIV?

Answer 7

Thrush
Erythematous candidosis
Gingival erythema
Hairy oral leukoplakia*

Question 8

What are drug targets?

Answer 8

1. Fusion inhibitors
2. NRTIs (nucleotide reverse transcriptase inhibitor- chain terminator)
3. NNRTIs
4. Integrase inhibitors
5. Protease inhibitors
6. CCR5 entry inhibitors

Question 9

What is the treatment for HIV?

Answer 9

HAART
Highly active antiretroviral therapy

First line-
2 NRTIs eg. Zidovudine and lamivudine
+ 1 NNRTI/PI/II eg. Nevirapine

Question 10

What are side effects to HIV drugs?

Answer 10

Headaches
Nausea
Anaemia
Neutropenia
Lactic acidosis
Lipoatrophy
Peripheral neuropathy
Rashes
Stevens Johnson syndrome
Teratogenecity
Lipodystrophy

RESISTANCE

Question 11

How should you manage a HIV pt?

Answer 11

Normal infectious control

If at risk- Occu health for prophylactic HAART and HIV testing

If needle stick- PEP administration ASAP and continual HIV testing

Question 12

How is HIV tested?

Answer 12

ELISA
detects antibodies
6–12 weeks after infection so 3 months most reliable
Babies may have false +ve due to cross placental antibodies so PCR

Question 13

Why is diagnosis important?

Answer 13

15% undiagnosed

If diagnosed late
-more likely to die
-transmission to others

Question 14

What are indicator illnesses for HIV?

Answer 14

Kaposis sarcoma
Severe/recalcitrant seborrhoeic dermatitis
Multidermatomal/recurrent herpes zoster
Oral candidiasis
Oral hairy leukoplakia
Head and neck cancer
Hodgkin’s lymphoma
Castlemans disease
Lymphadenopathy (unknown cause)
Chronic parotitis
Lymphoepithelial parotid cysts

Question 15

Why is oral candidiasis an indicator illness?

Answer 15

Unusual in healthy people
But VERY prevalent in HIV

Risk factors- antibiotics/immunocompromisation

ADVANCED INDICATOR

Question 16

Why is shingles an indicator illness?

Answer 16

Reactivation of varicella zoster virus
Dermatomal distribution
Painful blistering rash, malaise

Risk factors- age, immunocompromisation

Question 17

How do we test for HIV?

Answer 17

Verbal consent
Send clotted blood to lab
4th generation test (antibody/antigen, window period 1 month, costs <£5)
Confirmatory test 99.9% accurate

Question 18

What do you do if the pt is HIV +ve?

Answer 18

Call specialist for advice

Result
-YOU give the result
-face to face
-confidential environment

Contact tracing is done by specialist service

Question 19

What are other ways to test?

Answer 19

Point of care test
HIV RNA PCR

Question 20

What does Kaposis sarcoma look like?

Answer 20

Red-brown-purple lesion
Can be multiple
Can be in mouth
HHV8
Spindle cells on biopsy
Needs referral to oncology

ADVANCED INDICATOR

Question 21

What is hairy oral leukoplakia?

Answer 21

EBV
White patches can’t be scraped off
On tongue

ADVANCED INDICATOR

Question 22

Is herpes simplex virus an indicator illness?

Answer 22

In hiv
-more severe
-more frequent
-outbreaks last longer
-may also have genital herpes

ADVANCED INDICATOR

Question 23

How is HIV managed?

Answer 23

HAART
Highly active antiretroviral therapy
3+ drugs
Act on different points of HIV replication cycle

Question 24

How does HAART work?

Answer 24

Within CD4 cell
Drug blocks receptor to prevent virus binding (fusion/entry inhibitor)
Prevent transcription of viral RNA into viral DNA (NRTI)
Prevents viral DNA to be integrated into host DNA (Integrase inhibitor)
Repackaging of new virus is prevented (protease inhibitor)

Question 25

Why is HIV resistant to drugs?

Answer 25

50% mutation every time virus replicates
1-5 billion mutations/day

Question 26

Why are therapeutic drug levels important?

Answer 26

1. Non adherence- missing 1 or 2 doses can cause resistance
2. Drug-drug interaction- sub therapeutic levels