Investigation pathways for tuberculosis among HIV-positive adults in South Africa

Background and aims: The World Health Organization (WHO) recommendation for regular tuberculosis (TB) screening of people living with HIV (PLHIV) using a symptom screen (WHO tool), with Xpert MTB/RIF (Xpert) as the initial diagnostic test has major resource implications. This thesis examined alternative investigation pathways, including Determine TB-LAM (LF-LAM) for TB screening, a clinical score to triage symptomatic individuals for Xpert, and repeating Xpert if the initial test was negative. Design and setting: Prospective cohort of PLHIV, attending four HIV clinics in South Africa. Methods: A systematic sample of adults attending for routine HIV care were enrolled in the XPHACTOR study, which tested a novel algorithm for prioritising investigation with Xpert. At enrolment sputum was collected from all and sent for immediate Xpert if any of: current cough, fever ≥3 weeks, body mass index (BMI) < 18.5kg/m2, CD4 < 100 cells/mm3 (or < 200 if pre-ART) or weight loss ≥10%; otherwise, sputum was stored. Urine was stored if CD4 < 200 cells/mm3. At attendance for immediate Xpert result, further investigations were facilitated per national guidelines. For those at highest risk of TB, who had negative initial ... (continues)