Stool-Based Molecular Test May Enhance TB Detection in Adults with HIV: Study Reveals - Video

A new study showed that the Xpert MTB/Ultra molecular diagnostic test for stool samples, until now recommended only for children, could be established as an additional test for diagnosing tuberculosis in adults living with HIV. The results, published in The Lancet Microbe, could represent a paradigm shift in the diagnosis of the disease in this population.

Researchers from the Stool4TB project proposed using a molecular test, currently used on respiratory samples, on stool samples. This test is already recommended for children because they have difficulty producing sputum. The research was conducted between December 2021 and August 2024 in medical centres in three African countries -Eswatini, Mozambique, and Uganda-, and recruited 677 patients over 15 years old with HIV and suspected TB. Participants provided sputum, urine, stool, and blood samples.

The results showed that the stool test had a sensitivity of 23.7% and a specificity of 94.0%, compared with the reference standard. In patients with CD4 counts below 200 cells/μl, sensitivity increased to 45.5%. The Stool Ultra test identified additional cases that were not detected by TB-LAM, Ultra in sputum or bacterial culture.

“The results of our study support the use of the Stool Ultra test as a complementary tool for diagnosing tuberculosis in people living with HIV, especially in those with advanced AIDS, where the risk of tuberculosis is higher,” says Alberto L. García-Basteiro, a researcher at ISGlobal and head of the Vaccine and Immune Response to Infections Unit at Hospital Clínic de Barcelona.

Reference: Kasule, G., Hermans, S., Acacio, S., et al, Performance of stool Xpert MTB/RIF Ultra for detection of Mycobacterium tuberculosis among adult people living with HIV: a prospective multicentre diagnostic study. Lancet Microbe (2025). https://doi.org/10.1016/j.lanmic.2025.101085