Rapid urine-based screening tests increase the yield of same-day tuberculosis diagnoses among patients living with advanced HIV disease.

Abstract

Investigation of the diagnostic yield of urine-based tuberculosis (TB) screening in patients with advanced HIV disease. A cross-sectional screening study. HIV outpatient clinics and wards at two hospitals in Johannesburg, South Africa, between June 2015 and October 2017. Two hundred and one patients living with advanced HIV disease (CD4+ T-lymphocytes <100 cells/μl) attending healthcare facilities following cryptococcal antigen (CrAg) screening. Screening for TB using sputum for microscopy, culture, and Xpert MTB/Rif and urine for lipoarabinomannan (LAM) and Xpert Ultra. Proportion of positive results using each testing modality, sensitivity, and specificity of urine-based testing compared with culture, and survival outcomes during 6 months follow up. Urine was obtained from 177 of 181 (98%) participants and sputum from 91 (50%). Urine-based screening increased same-day diagnostic yield from 7 (4%) to 31 (17%). A positive urine test with either LAM or Xpert Ultra had 100% sensitivity (95% confidence interval, 59-100%) for detecting culture-positive TB at any site. Patients with newly diagnosed TB on urine-based screening were initiated on treatment and did not have excess mortality compared with the remainder of the cohort. Urine is an easily obtainable sample with utility for detecting TB in patients with advanced HIV disease. Combining urine and sputum-based screening in this population facilitates additional same-day TB diagnoses and early treatment initiation, potentially reducing the risk of TB-related mortality. Urine-based as well as sputum-based screening for TB should be integrated with CrAg screening in patients living with advanced HIV disease.