HIV Infection

Clinical manifestations

• Seroconversion
  • Fever
  • Lymphadenopathy
  • Malaise
  • Rash
  • Myalgia / arthralgia
  • Sore throat
  • Headache
• Early symptomatic HIV (B conditions – occur with other disorders but more frequent / severe with HIV)
  • Vaginal candidiasis
  • Oral hairy leukoplakia
  • Herpes zoster (recurrent or disseminated)
  • Cervical carcinoma in situ
  • Immune thrombocytopaenia purpura
  • Psoriasis
• AIDS-defining illnesses (or CD4 count < 200)
  • AIDS wasting syndrome
  • Recurrent
    • Pneumonia
    • Bacterial infections of any kind
    • Salmonella bacteraemia
  • Respiratory tract
    • Pneumocystis jirovecii infection
    • Mycobacterium tuberculosis infection (of any site)
    • Mycobacterium avium complex (disseminated or extra-pulmonary)
    • Recurrent pneumonia
  • Gastrointestinal tract
    • Oesophageal candidiasis (odynophagia)
    • Cytomegalovirus infection (chronic diarrhoea)
    • Chronic intestinal cryptosporidiosis (> 1 month)
    • Chronic intestinal isosporiasis
  • Central nervous system
    • Cryptococcal meningitis
    • Cerebral toxoplasmosis
    • Progressive multifocal leukoencephalopathy
    • HIV-related encephalopathy
  • Malignancy
    • Lymphoma
    • Karposi’s sarcoma
    • Invasive cervical cancer

Investigation

• HIV antibody testing – 4^th generation ELISA (98% sensitivity and specificity)
• Confirmation with Western blot (this combination gives very high positive predictive value)
• Can be supported by testing for HIV viral load or repeating test at different intervals

Management

• Antiretroviral therapy
  • Indications
    • CD4 count ≤ 500
    • In the setting of opportunistic infection
    • Early ARV decreases AIDS progression, lowers viral set-point and reservoir and transmission
  • Types (bay all cause worsening glycaemic control and dyslipidaemia)
    • Nucleoside reverse transcriptase inhibitors (NRTIs)
      • Abacavir (ABC) – hypersensitivity syndrome (can be fatal)
      • Emtricitabine (FTC)
      • Lamivudine (3TC)
      • Stavudine (D4T)
      • Zidovudine (ZDV) – anaemia, lactic acidosis, peripheral neuropathy, lipodystrophy
      • Tenofovir (TDF) – Fanconi syndrome (NAGMA, low K, PO₄, glycosuria)
    • Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
      • Efavirenz (EFV) – giddiness, neuropsyhiatric side-effects (usually given ON)
      • Etravirine (ETR)
      • Rilpivirine (RPV)
    • Protease inhibitors (PIs) – ritonavir can reduce side-effects of PI (give together = boosted PI)
      • Atazanavir (ATV) – renal stones, unconjugated bilirubinaemia
      • Darunavir (DRV) – transaminitis
      • Lopinavir (LPV) – diarrhoea
    • Integrase inhibitors (II)
      • Raltegravir (RAL)
    • CCR5 inhibitors
      • Maraviroc
    • Combinations
      • 1 NNRTI + 2 NRTIs
      • 1 PI + 2 NRTIs
      • 1 II + 2 NRTIs
• Prophylaxis
  • CD4 ≤ 200 – PCP prophylaxis (Bactrim)
  • CD4 ≤ 100 – toxoplasmosis (Bactrim)
  • CD4 ≤ 50 – Mycobacterium avium complex (azithromycin)
• Post-exposure prophylaxis
  • Given to patients exposed to blood or bodily fluids of patients who are known to be HIV positive
  • Must be given within 36 hours
  • Tenofovir + lamivudine + raltegravir
  • 28-day course
• Pre-exposure prophylaxis (PrEP)
  • Given to HIV-negative individuals to decrease their risk of acquiring HIV
  • Tenofovir + emtricitabine (Truvada®) one tablet OM
  • Take daily
  • Review need for continued PrEP every 90 days
• Opportunistic infections
  • Pneumocystis jirovecii pneumonia
    • Bactrim (15-20mg/kg/day of trimethoprim)
    • Prednisolone 40mg OM if PaO₂ < 70 mmHg on room air
    • Chest drain for pneumothorax
    • Often worsens transiently on day 5 of treatment
  • Toxoplasmosis
    • Sulfadiazine
    • Pyrimethamine
    • Leucovorin to prevent myelosuppression with pyrimethamine
• Vaccinations
  • Influenza
  • Pneumococcal vaccine
  • Hepatitis B
  • Hepatitis A
  • Varicella zoster virus (if not previously infected and CD4 count ≥ 200)