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Urine Test for TB Yields Results in 12 Hours

The new test could improve upon two current methods to diagnose tuberculosis—a skin test or culturing bacteria from saliva, both of which take days.

By | December 14, 2017

WIKIMEDIA, TURBOTORQUEResearchers have developed a new urine test for tuberculosis (TB) that is up to 1,000 times more accurate than previous urine tests and much faster than two currently used methods of diagnosing the disease. Compared with a TB skin test or bacterial culture, which take days to return results, the new technique, which detects the LAM sugar found in the outer coat of the TB bacterium, takes only 12 hours.

The test uses a copper complex dye called RB221, embedded in hydrogel nanocages, to trap LAM from urine samples. When Alessandra Luchini of George Mason University and colleagues trialed the diagnostic on 48 people with TB, the test successfully returned positive results with greater than 95 percent sensitivity, even though the sugar is often only found in low concentrations in the urine. The results were published yesterday (December 13) in Science Translational Medicine.

If further refinement and assessments go well, this test could be available within three years, Luchini tells New Scientist.

Clarification (December 14): This story has been updated to clarify that the skin and bacterial culture tests are not the only current TB diagnostics. A third test for TB—an interferon gamma release assay—returns results in less than 24 hours but cannot distinguish between active and latent infection. The Scientist regrets any confusion.