Urine test finds many missed TB cases in people with advanced HIV

Tuberculosis diagnosis is a persistent weak link in care for people living with HIV and AIDS (PLHIV), especially those with advanced HIV disease (AHD) who often cannot produce usable sputum for standard tests. The problem is acute in settings where extrapulmonary TB is common and patients are severely immunocompromised. To address this gap, Justin Onyebuchi Nwofe and colleagues evaluated a urine-based rapid test, Determine Urine TB LF-LAM®, which detects the lipoarabinomannan antigen and can work even when TB is outside the lungs. The researchers ran a large, cross-sectional diagnostic study in routine program settings across Nigeria, enrolling adults and children under 5 years with AHD from 334 selected HIV treatment facilities between July 2022 and July 2025. The goal was to measure how many TB cases this urine test would detect in real-world HIV clinics and to compare its results with the more familiar molecular test GeneXpert MTB/RIF, which relies on sputum.

The team measured diagnostic yield and accuracy by testing first urine samples with Determine Urine TB LF-LAM® and, in a paired-testing group, comparing results to GeneXpert MTB/RIF. Of 17,155 AHD patients tested with LF-LAM on first urine samples, 5,212 were positive, giving a diagnostic yield of 30.4%. Strikingly, 2,074 of those 5,212 LF-LAM positives (41%) were not flagged as presumptive TB cases by WHO four-symptom screening and therefore would have been missed without LF-LAM. In the subgroup that received both tests (3,138 patients), GeneXpert MTB/RIF detected 1,914 TB cases. An additional 1,224 GeneXpert-negative patients tested positive with TB LF-LAM, producing an incremental diagnostic yield of 39% for LF-LAM over GeneXpert (1224/(1,914+1224); Wilson 95% CI). The discordance between tests was statistically significant (McNemar p<0.001).

These findings show that Determine Urine TB LF-LAM® substantially boosts TB case detection among PLHIV with AHD in routine Nigerian HIV programs. The urine test picked up many cases in children and severely immunocompromised patients who cannot produce sputum or who may have extrapulmonary TB, and it identified a large number of infections that would not have been caught by WHO four-symptom screening or by sputum-based GeneXpert MTB/RIF alone. Because the test is simple to use and non-invasive, the high incremental yield argues for integrating LF-LAM with molecular testing in programmatic care to close diagnostic gaps. The authors suggest that adding Determine Urine TB LF-LAM® to standard AHD care packages could reduce missed diagnoses and help lower TB-related deaths in high-burden, resource-limited settings like Nigeria.