Performance of urine Xpert MTB/RIF ultra in a tuberculosis screening strategy in hospitalized patients with advanced HIV disease: Results from an implementation initiative in Brazil

Objectives

To evaluate the performance of Xpert MTB/RIF Ultra testing in urine samples as part of a TB screening strategy in patients with advanced HIV disease (AHD).

Methods

We conducted a multicentre prospective cohort study across three HIV reference hospitals in Brazil, between January and December 2023. The study included adult hospitalized patients with AHD, defined by a CD4 count of <200 cells/μL in the last 3 months or clinical presentation suggestive of opportunistic infection, without effective antiretroviral treatment. Participants underwent systematic tuberculosis (TB) screening using urine Xpert MTB/RIF Ultra and TB lipoarabinomannan (TB-LAM) tests. The diagnosis performance of urine Xpert MTB/RIF Ultra was assessed including sensitivity, specificity, and positive and negative predictive values. Disease characterization was based on the Global Tuberculosis Dictionary. Survival at 30 and 90 days was also evaluated.

Results

Urine molecular testing was performed on 133 patients. Xpert MTB/RIF Ultra showed a sensitivity of 20.7% in bacteriologically confirmed TB cases and 21.2% in cases that included both clinically diagnosed and bacteriologically confirmed TB. The addition of urine Xpert MTB/RIF Ultra to TB-LAM led to the detection of three additional cases, representing a 6.3% increase from the 48 cases detected by TB-LAM. Xpert MTB/RIF Ultra had a specificity of 96.9% and no rifampicine resistance mutations were detected. Overall mortality was 16/133 (12.0%) at 30 days and 25/127 (19.7%) at 90 days.

Conclusions

There was a high overlap between urine TB-LAM and Xpert MTB/RIF Ultra results, with the addition of Xpert MTB/RIF providing limited additional benefit for TB screening in patients with AHD.