Prior to the initiation of lifelong ART, it is recommended that HIV infection is confirmed with two different testing methods, at least one of which should be a laboratory-based test. Acceptable combinations include:
- Rapid test + ELISA
- Rapid test + VL
- ELISA + VL.
Note that a VL may be undetectable in < 1% of patients not receiving ART, i.e. ‘elite controllers’.
Baseline investigations for ART are summarised in Table 8.
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|TABLE 8: Summary of baseline investigations for antiretroviral therapy.|
|CD4+ count||If CD4+ count < 200 cells/μL, then CPT is required and serum/plasma CrAg testing needs to be performed.|
|Baseline VL||Can also serve as a confirmatory HIV test.|
|ALT||If raised, then will need workup and may influence ART regimen choice.|
|Creatinine||Avoid TDF if CrCl < 50 mL/min. Other NRTIs, except ABC, require dose adjustment if CrCl < 50 mL/min.|
|HBsAg||See Module 20.|
|sCrAg||Only required in patients with a CD4+ count < 200 cells/μL. If sCrAg-positive, exclude CM by LP. See section on CM management (Module 27) for further details.|
ABC, abacavir; ALT, alanine transaminase; ART, antiretroviral therapy; CrAg, cryptococcal antigen; CrCl, creatinine clearance rate; CM, cryptococcal meningitis; CPT, cotrimoxazole preventive therapy; HBsAg, hepatitis B surface antigen; HIV, human immunodeficiency virus; NRTI, nucleoside reverse transcriptase inhibitor; LP, lumbar puncture; sCrAg, serum cryptococcal antigen; TDF, tenofovir disoproxol fumarate; VL, viral load.
We also advise a symptom screen for:
- Tuberculosis (TB): patients should be asked about cough, weight loss, fever, night sweats and a possible TB contact. If any of these symptoms are present, then sputum should be sent for Xpert analysis; and if hospitalised or CD4+ count < 200 cells/μL, then a urine lipoarabinomannan (LAM) assay should be performed.
- Cryptococcal meningitis (CM): patients should be asked about new-onset of headache; sCrAg testing and possibly a lumbar puncture (LP) should be performed if this symptom is present.
If the patient’s symptom screen is positive, then ART should be deferred until the results of the Xpert, LAM, sCrAg test or LP (as indicated) are known. Delays in this process should, however, be kept to a minimum.