Tuberculosis (TB) has been treatable for more than 75 years, yet it remains the world’s deadliest infectious disease, killing more people each year than any other single pathogen. The paradox has long frustrated global health experts: Effective drugs exist, but the disease continues to spread and claim lives, particularly in low- and middle-income countries.
One of the biggest obstacles is not treatment, but diagnosis. Current TB testing is either insufficiently accurate or dependent on laboratory infrastructure that is often unavailable in the regions where TB is most prevalent. As a result, millions of cases are missed every year, and patients may wait days or weeks for results — if they are tested at all.
However, that could quickly change. A new portable diagnostic device called MiniDock MTB can deliver accurate TB results in less than 30 minutes, according to a study published in the New England Journal of Medicine by researchers at the University of California, San Francisco and the University of California, Irvine (UC Irvine).
Bringing better diagnosis to the patient
For decades, TB testing in many high-burden countries has relied on approaches that have changed very little since the 19th century. The most widely used method is smear microscopy, which involves examining sputum samples under a microscope after staining them with dye to detect the presence of Mycobacterium tuberculosis, the bacterium that causes the disease. While inexpensive, the method is limited in sensitivity and often misses cases, particularly in people with early or less advanced infection.
More advanced molecular tests exist, but they typically require centralized laboratories, trained personnel, and stable infrastructure — resources that are often scarce in rural clinics and under-resourced health systems. In many cases, patients leave clinics without a confirmed diagnosis, contributing to ongoing transmission and worse outcomes.
Diagnostic performance is further constrained in specific patient groups. The same tests are often less effective in individuals living with HIV, in whom immune responses may be diminished, as well as in children who are unable to produce sputum samples containing sufficient bacterial material.
MiniDock MTB aims to bridge that gap by bringing molecular-level accuracy to the point of care (POC). The portable device is battery-powered and requires minimal training, making it suitable for settings where power access is unreliable or intermittent. Additionally, MiniDock MTB can also work with non-invasive tongue swabs, which are easier to collect and more feasible in patients who struggle to produce sputum. Once a sample is collected, the device uses molecular detection technology to identify genetic material from M. tuberculosis, producing results in under 30 minutes.
“For patients who can’t produce sputum, like children or people with HIV, tongue swabs move the needle from ‘no diagnosis possible at this clinic’ to ‘accurate molecular testing here now,’” Adithya Cattamanchi, a professor of medicine at UC Irvine and co-lead author of the study, said in the press release.
The sample preparation is also simple. Instead of requiring multiple laboratory steps, the sample is collected using a swab and then placed into a processing tube where it is broken down using a combination of heat and beads. This step helps release the genetic material of M. tuberculosis without the need for complex extraction procedures or specialized equipment. Once processed, the material can be loaded directly into the test device, which carries out the molecular detection and produces a result in the same setting.
TB diagnostics need to be cheaper, easy-to-use, and quick
The device was evaluated in outpatient clinics across multiple countries, including India, Nigeria, the Philippines, South Africa, Uganda, Vietnam, and Zambia. This enabled researchers to test the device under real-world conditions across a range of high-burden settings, rather than in controlled laboratory environments. The study included more than 1,300 participants, reflecting a broad mix of clinical presentations, co-morbidities, and health system contexts, including a substantial proportion of patients living with HIV.
In order to directly benchmark its performance, researchers compared the MiniDock MTB with established diagnostic tools such as smear microscopy and the Xpert MTB/RIF Ultra assay, the current molecular benchmark used in many clinical settings. Crucially, MiniDock MTB demonstrated diagnostic performance that met World Health Organization target product profile standards for POC TB tests, with sensitivity above 85 percent for sputum samples and close to 80 percent for tongue swabs, alongside specificity consistently above 97 percent. Its accuracy was broadly comparable to the widely used Xpert MTB/RIF Ultra assay and substantially outperformed smear microscopy.
Beyond performance, the system was also assessed for usability among frontline healthcare workers. Participants, including clinicians, nurses, and laboratory technicians, were able to operate the device after reading the instructions, suggesting the test could be deployed with minimal training in primary care settings.
The system is also designed with affordability in mind, with a device cost of under $180 and an estimated per-test cost of less than $4, according to the study authors. This compares well with the GeneXpert platform, which typically costs between $17,000 and $20,000 for the instrument itself, alongside an approximate $7.97 cost per Xpert MTB/RIF Ultra test in high-burden countries following recent price reductions.
However, the two systems are not fully equivalent in function. While MiniDock MTB is designed for rapid, decentralized detection at the POC, Xpert MTB/RIF Ultra also provides information on drug resistance, allowing clinicians to distinguish between drug-sensitive and rifampicin-resistant TB — a key consideration in treatment planning.
Controlling and eradicating TB
Global health researchers have long argued that TB control depends as much on diagnostics as on drugs. While antibiotic regimens can cure most cases of drug-sensitive TB, delayed or missed diagnosis allows the disease to spread, particularly in crowded living conditions associated with poverty and limited healthcare access.
The introduction of a faster, simpler test could reduce those barriers by enabling same-day diagnosis and treatment decisions. “Patients who today would have to leave a clinic undiagnosed could soon be diagnosed and treated the same day,” Cattamanchi said. “We hope to see more widespread adoption as evidence like ours stacks up.”
Despite decades of medical advances, TB continues to exploit weaknesses in global health systems, particularly those shaped by inequality. The arrival of portable molecular diagnostics may not eliminate those structural challenges, but it could shift the balance — bringing accurate testing closer to the communities that need it most.
