Diagnosing a lung disease like tuberculosis with a urine test may seem illogical, but a group of American researchers is now a step closer to that goal.

Scientists at George Mason University have improved by at least 100 times the accuracy of testing for a sugar shed by tuberculosis bacteria, meaning that a simple dipstick urine test may soon become possible.

The researchers’ study was published last month in Science Translational Medicine.

Tuberculosis kills about 1.7 million people a year, according to the World Health Organization — more than are killed now by AIDS. While many people carry inactive bacteria, about 10 million fall ill annually and develop coughs that transmit the infection.

If they could be found and treated sooner, more would be cured and the spread would slow.

For decades, tuberculosis was diagnosed by chest X-rays, skin or blood tests, or by reading sputum samples under a microscope. But the W.H.O. has condemned skin and blood tests as inaccurate, X-rays detect only advanced damage, and microscopy requires trained pathologists.