New blood test for tuberculosis could reduce the spread of this top global infectious-disease killer

by Association for Diagnostics & Laboratory Medicine

edited by Swati Mestri, reviewed by Andrew Zinin

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A new study presented today at ADLM 2026 in Anaheim, California, found that a simple blood test could accurately identify tuberculosis (TB)—a leading cause of death worldwide—among patients with varying degrees of exposure to the disease. If confirmed, these results could help save millions of lives and curb a global health emergency.

"Every week of delay in diagnosing TB matters—so early identification may allow treatment to begin sooner and potentially reduce transmission," said Dr. Sheng-Wei Pan, a physician in the Department of Chest Medicine at Taipei Veterans General Hospital in Taiwan and the study's lead author. According to the World Health Organization, a quarter of the global population is estimated to have been infected with the TB bacterium (Mycobacterium tuberculosis), and 5%–10% will develop active disease.

TB is almost always curable with antibiotic therapy when M. tuberculosis is detected in the initial stages of disease progression. It is typically diagnosed by assessing samples of patients' sputum, mucus secretions coughed up from the lungs and airways.

"However, not all patients can produce sputum when they first seek medical care, especially those with early disease or those with low bacterial burden," Pan said. For that reason, non-sputum-based diagnostic tools are urgently needed.

The researchers evaluated a blood marker produced by the bacterium called 6-kDa early secreted antigenic target (ESAT-6). While ESAT-6 has been studied before, most sensors used to detect it have not been sensitive enough to distinguish active pulmonary TB from latent TB infection, TB exposure or other lung diseases. Pan's team used a new biosensor that overcame this limitation.

"The novelty of our study lies in the highly sensitive quantification of circulating ESAT-6," Pan said.

The researchers quantified ESAT-6 levels in blood samples from 217 patients who either had active pulmonary TB infection (cases) or did not (controls). The control group was further classified into patients with lung disease caused by Mycobacterium species other than the one that causes TB, those with lung cancer, people with latent TB infection (no symptoms) after exposure to someone with TB, uninfected people who were exposed to someone with TB, and healthy people with no known TB contacts.

The ESAT-6 marker did an excellent job of differentiating between TB and non-TB patients. Moreover, the researchers noted a stepwise increase in the blood concentration of the marker across the spectrum of TB infection, with the lowest levels in uninfected people with TB contacts, intermediate levels in those with latent TB, and the highest levels in patients with active TB. This strong, independent association held true even after the researchers accounted for other factors that could affect patients' TB status, such as age, sex and the presence of diabetes.

Unlike biomarkers that measure the body's immune response to infection, ESAT-6 is derived directly from the TB bacterium. "We believe this is one reason why it performs so well in identifying active TB," Pan said. The study found ESAT-6 did a better job of discriminating among TB patient groups than two common blood-based markers.

Because the study used a design in which patients' disease status was known from the outset, further research is needed to confirm that ESAT-6 can predict TB status in real time. "We are currently planning a prospective study to further evaluate if this can be used in a real-world clinical setting," Pan said.

Although sputum cultures remain essential for verifying TB and providing information about drug resistance, ESAT-6 holds promise as a practical tool for triaging patients when sputum-based diagnostics are limited or delayed.

More information

Abstract A-097: Quantitative assessment of circulating blood ESAT-6 for non-sputum identification of pulmonary tuberculosis, ADLM 2026.

Key medical concepts

TuberculosisMycobacterium tuberculosisProspective Studies

Clinical categories

Infectious diseasesLaboratory medicineCommon illnesses & Prevention Provided by Association for Diagnostics & Laboratory Medicine Who's behind this story?

Swati Mestri

Swati Mestri holds a bachelor's degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space. Full profile →

Andrew Zinin

Master's in physics with research experience. Long-time science news enthusiast. Plays key role in Science X's editorial success. Full profile →

Citation: New blood test for tuberculosis could reduce the spread of this top global infectious-disease killer (2026, July 28) retrieved 28 July 2026 from https://medicalxpress.com/news/2026-07-blood-tuberculosis-global-infectious-disease.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.