Blood Test for Tuberculosis Could Cut Spread of Global Infectious Killer

A study presented at ADLM 2026 in Anaheim, California reports that a blood test could identify active tuberculosis (TB) with high accuracy across a spectrum of exposure levels. TB remains a major global killer, and faster diagnosis is widely seen as a practical lever for reducing transmission. The findings, if validated in real-world workflows, may help clinicians act sooner—especially when standard sputum testing is not feasible.

Dr. Sheng-Wei Pan of Taipei Veterans General Hospital, lead author of the work, emphasized that “every week of delay” matters for both patient outcomes and public health. The World Health Organization estimates that roughly one-quarter of the global population is infected with Mycobacterium tuberculosis, and 5–10% may progress to active disease. Early detection followed by antibiotic treatment can be lifesaving and can reduce onward spread.

Traditionally, TB diagnosis relies on sputum samples, which require patients to produce mucus from the lungs and airways. That approach can fail in early infection or in cases with low bacterial burden, leaving clinicians without a reliable, non-sputum alternative. A blood-based method would broaden access to testing in settings where collection and lab turnaround are limiting factors.

The study centers on a bacterial marker: 6-kDa early secreted antigenic target (ESAT-6). While ESAT-6 has been studied previously, many sensors have struggled to distinguish active pulmonary TB from latent TB infection, prior exposure without infection, TB caused by other Mycobacterium species, lung cancer, or other lung disorders. The team addressed this challenge using a biosensor designed for highly sensitive quantification of circulating ESAT-6.

Researchers measured ESAT-6 levels in blood from 217 participants with confirmed active pulmonary TB or with non-TB conditions. The control group included lung disease from non-TB Mycobacterium species, lung cancer, latent TB, exposed but uninfected individuals, and healthy participants with no known TB contact. The marker clearly separated TB from non-TB participants.

Importantly, ESAT-6 concentrations showed a stepwise pattern: lowest in uninfected contacts, intermediate in latent TB, and highest in active TB. This relationship remained robust even after accounting for variables such as age, sex, and diabetes. Because ESAT-6 originates directly from the bacteria rather than from the host immune response, the signal may better reflect disease activity.

Compared with two commonly used blood-based markers, ESAT-6 demonstrated improved discrimination among clinical TB groups. Still, the researchers note that their study design used known disease status from the outset, so prospective testing is needed to establish predictive performance over time.

While sputum cultures remain essential for confirmation and drug-resistance profiling, ESAT-6 could provide a fast, practical triage tool when sputum diagnostics are delayed or limited. The team is planning a prospective study to evaluate whether the test can guide clinical decision-making in real-world settings.