HIV/AIDS

Question 1

HIV - background

Answer 1

1. Retrovirus found in blood, vaginal fluid and semen
2. Infects T lymphocytes (CD4 cells), macrophages and dendritic cells
3. AIDS = advanced immunodeficiency
4. Transmission = sex, needle sharing, contaminated blood products, vertical transmission during childbirth or breastfeeding.
5. Approximately 30,000 Australians live with HIV

Question 2

HIV - symptoms

Answer 2

1. 50% of those infected experience a seroconversion illness (similar to IM) between 2-4 weeks post transmission = headache, fever, nausea, myalgia, swollen glands, mouth ulcers, maculopapular rash
2. The early symptoms resolve over 2-3mo, and a variable dormant phase follows
3. Once the immune system is compromised, a wide range of clinical symptoms may follow, including generalised lymphadenopathy, fever, weight loss, chronic diarrhoea, anaemia, oral thrush and recurrent shingles
4. Most Australian pts are diagnosed during this phase of the illness
5. Small number present with AIDS-defining illness

Question 3

HIV - ix

Answer 3

1. Pre-test counselling + informed consent. Also post-test counselling
2. Serology using commercial ELISA screening test
   - If test result negative, second test 3mo after last exposure
   - If test positive, confirm result using two different immunoassays +/- Western blot
3. NAAT if seroconversion suspected (?), or if confirming vertical transmission
4. CD4 cell count, plasma HIV RNA (viral load)
5. HBV, HCV, FBE, UEC, LFTs, BGL (fasting), serum lipids

Question 4

HIV - mx

Answer 4

Four classes of antiretroviral drugs used for initial therapy:

1. Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)
2. Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
3. Protease inhibitors (PIs)
4. Integrase inhibitors

Recommended combinations = 2 NRTIs (emtricitabine + tenofovir), plus either an NNRTI (efavirenz), or a PI (atazanavir + ritonavir), or an integrase inhibitor (dolutegravir... etc.)
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5. Two other classes of drugs (fusion inhibitors and entry inhibitors), particular drugs of the PI class and the NNRTI class are reserved for use in resistant infection or when pts are unable to tolerate standard therapy

Question 5

HIV - other mx

Answer 5

1. Monitor antiretroviral therapy. Assess patients 2-4 weeks after starting tx, then every 3-4mo if stable. Check clinical status and tx adherence, HIV viral load, CD4 cell count, toxicity of therapy
2. Discuss transmission and need for behaviour modification (safer sex, needle exchange)
3. Immunisations = HAB, HBV (if not immune), pneumococcal vaccine, influenza, consider tetanus booster
4. Notifiable disease. Contacting and informing partners
5. Pre-pregnancy counselling if planning pregnancy