HIV

Question 1

Describe HIV to a lay person

Answer 1

• HIV stands for human immunodeficiency virus, it is a virus in a group of viruses called retroviruses
• This virus attacks cells in your body called CD4 T cells
• These cells are normally responsible for fighting off other infections from bacteria, parasites and other fungi
• As these cells are killed off the body is less able to protect itself from other infections

Question 2

Describe AIDS to a lay person

Answer 2

• AIDs stands from acquired immunodeficiency syndrome and describes the range of illnesses that develops from HIV
• Due to advances in medications the term AIDs is being used less and less and being replaced with late-stage HIV
• HIV and AIDs is not the same thing a people do not automatically develop AIDs from an HIV infection. With treatment in the early-stage of HIV, AIDs is unlikely to develop.
• Even if HIV is not treated it may be several years before AIDs develops as it take this amount of time for CD4 levels to reach a low enough count that other infections may be contracted.

Question 3

How is HIV transmitted?

Answer 3

Mixture of infected blood, semen and vaginal secretions with blood

SEXUAL ACTIVITY
IVDU - needle exchange
Accidental needle stick injury (no UK cases since 1999)
Vertical transmission
Blood products (now v. rare since 1985 blood screening program)

Question 4

What are the transmission rates per sexual encounter/during child birth?

Answer 4

Anal sex – receiving partner – between 0.1 – 3%
Anal sex – active partner - <0.1%
Vaginal sex – female – 1 in 100,000
Vaginal sex – male – 1 in 200,000
Oral sex – less than 1 in 200,000

Child birth – 15%
Child birth + breast feeding – 25%

Question 5

What is the UK epidemiology of HIV?

Answer 5

• Currently 100,000 living with HIV
• Used to be higher rate in homosexual communities
• Rate in heterosexuals increasing

Question 6

What are the clinical features of HIV during the seroconversion stage?

Answer 6

Seroconversion stage - typically occurs 6-8 weeks following infection

In 60-80% have a glandular-like picture illness

• sore throat
• lymphadenopathy
• malaise, myalgia, arthralgia
• diarrhoea
• maculopapular rash
• mouth ulcers
• rarely meningoencephalitis

Question 7

What is the stage following seroconversion stage and its features?

Answer 7

ASYMPTOMATIC STAGE
-Can last for years

30% patients may have generalised lymphadenopathy

Question 8

How is HIV diagnosed?

Answer 8

-P24 antigen – present in the blood in the first 3 months of infection. Usually levels drop by the time IgG and IgM are produced (3 months). Levels rise again as immunodeficiency develops.

-HIV RNA – can also be detected using PCR techniques during the early stages of the infection
Used to monitor progress and effectiveness of treatment

• IgG and IgM – levels detectable after 3 months. Fall as immunodeficiency develops (try looking for P24).
• OraQuick – is a method of detecting HIV antibodies in saliva. Fast and easy, but high false positives.

Question 9

Where is universal HIV testing offered?

Answer 9

• Genitourinary medicine (GUM) or sexual health clinics.
• Antenatal services.
• Termination of pregnancy services.
• Drug dependency programmes.
• Healthcare services for those diagnosed with tuberculosis, hepatitis B, hepatitis C and lymphoma.

Question 10

What is HAART and what is the usual combination of medications?

Answer 10

Highly active anti-retroviral therapy (HAART)
-Recommended to start as soon as diagnosed

Combination of usually:
x 2 nucleoside reverse transcriptase inhibitor (NRTI)
AND EITHER
x 1 Protease inhibitor
OR
x1 non-nucleoside reverse transcriptase inhibitor

Question 11

What is the drug profile of NRTIs?

Answer 11

Nucleoside analogue reverse transcriptase inhibitors (NRTI)

EG. zidovudine (AZT), didanosine, lamivudine, stavudine, zalcitabine

SIDE EFFECTS

• General: peripheral neuropathy
• Zidovudine: anaemia, myopathy, black nails
• Didanosine: pancreatitis

Question 12

What is the drug profile of NNRTIs?

Answer 12

Non-nucleoside reverse transcriptase inhibitors (NNRTI)

EG. nevirapine, efavirenz

SIDE EFFECTS
P450 enzyme interaction (nevirapine induces), rashes

Question 13

What is the drug profile of PIs?

Answer 13

Protease inhibitors (PI)

EG. indinavir, nelfinavir, ritonavir, saquinavir

SIDE EFFECTS

• General: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition
• Indinavir: renal stones, asymptomatic hyperbilirubinaemia
• Ritonavir: a potent inhibitor of the P450 system