WHO backs $4 tongue swab TB test in 30 minutes

A $4 portable system called MiniDock MTB can detect tuberculosis from tongue swabs in about 30 minutes, with results delivered in community settings without laboratories or heavy technical training. The World Health Organization recommended the test in March,

The moment a tuberculosis diagnosis is delayed, the disease keeps moving—often past the point where timely treatment can prevent severe illness and spread to others. For many people, that delay doesn’t come from lack of care. It comes from the testing itself.

On April 29. researchers reported in the New England Journal of Medicine that a portable device using $4 tests can detect tuberculosis. or TB. from tongue swabs within just 30 minutes. The World Health Organization recommended the test in March. the first official endorsement for a TB test that can be used at community sites without laboratories and with minimal technical expertise.

For Adithya Cattamanchi. a pulmonologist at the University of California. Irvine. the recommendation matters because it helps put accurate molecular testing where most people with TB actually show up. “Opens a pathway to getting accurate molecular TB testing into the clinics where most people with TB actually show up. ” he said.

Tuberculosis remains the world’s most lethal infectious disease. Of the over 10 million people who suffer from TB each year, more than one-quarter remain undiagnosed or untreated. The gap is partly built into older diagnostic tools. Smear microscopy. which has been used for around 150 years. tests phlegm to detect the type of bacteria that cause infections like TB. While this test determines TB disease within 24 hours. at least 1 in 4 people—including children. people with HIV and the elderly—cannot produce phlegm adequately. Smear microscopy also misses over 40 percent of TB cases.

Because of these limitations, WHO recommends diagnostics that generate copies of DNA traces from the bacterium causing TB. Those tests can detect disease within hours, but they require expensive laboratory infrastructure.

MiniDock MTB—developed by the Guangzhou, China–based company Pluslife Biotech—was designed to close that divide. It is “designed to work anywhere: a rural clinic. a community health post. even outdoors. ” optimizing roughly a decade of research on oral swabs for TB. Cattamanchi says. The setup works with a power bank or wall power, costs under $400, and requires minimal training.

The workflow begins with collecting a tongue swab or phlegm sample. A machine spins and heats the tube containing the sample to release any genetic material. Then a worker pours the sample into a slot in a test card and loads it into the MiniDock testing platform to detect TB bacterial DNA in 12 to 25 minutes.

In Uganda, patients take tuberculosis tests which deliver results within 30 minutes. The tabletop devices that assess them for the disease are easy to use and do not require expensive laboratory facilities—an approach intended to bring testing closer to where patients live.

To evaluate performance. Cattamanchi and colleagues collected tongue swabs and phlegm samples from 1. 380 people aged 12 or older from seven countries with high TB rates. MiniDock MTB successfully detected TB in 86 percent of TB-positive phlegm samples and 80 percent of TB-positive tongue swabs. meeting WHO’s accuracy goals. In addition. its tests with phlegm outperformed smear microscopy by 24 percent and were similar to standards for an expensive lab test.

Yet the technology also has limits—ones that land right where TB is most difficult to catch early. The test was more accurate when detecting TB from phlegm compared with swabs. And Cattamanchi stressed that the trade-off isn’t only about numbers: “accuracy isn’t the whole story” because for patients who cannot produce phlegm. a tongue swab is “the difference between getting a test and getting nothing.”.

MiniDock MTB also does not detect drug-resistant TB. Pluslife is fast-tracking the development of such cards.

The sensitivity problem is another real-world obstacle. The test’s sensitivity declined if samples had few bacteria, which happens in the early stages of the disease. “This isn’t just a problem for tongue swab samples. ” says epidemiologist Emily MacLean at the University of Sydney. who wasn’t involved in the study but is part of a group conducting TB screenings with MiniDock. “When there aren’t many bacteria present, it is just harder for tests to find a signal.”.

A common requirement in public health is to use the right test at the right time—and sometimes to combine tests. MiniDock should be used in conjunction with other tests to improve the possibility of early TB detection. says epidemiologist Amira Roess at George Mason University College of Public Health in Fairfax. Va. who wasn’t part of the study.

Even as MiniDock focuses on bacterial DNA in airway samples. Cattamanchi and colleagues are also testing TB diagnostics based on RNA patterns in blood. proteins and metabolites. to detect the disease without requiring any specimen from the airway. Tongue swab testing cannot replace every test. Cattamanchi says. but it can be a “tool that can get the right test to the right person at the right time.”.

The biggest shift, then, may not be a new kind of TB test—it’s a new kind of access. With WHO’s March recommendation and results delivered in roughly 30 minutes. the promise is simple: get molecular accuracy to the places where TB is actually encountered. before too many people slip through the cracks.

tuberculosis TB test tongue swab MiniDock MTB Pluslife Biotech World Health Organization New England Journal of Medicine molecular diagnostics smear microscopy drug-resistant TB