Stanford University School of Medicine researchers have found a gene that shows the difference between tuberculosis (TB) that is active versus tuberculosis that is not.
A paper in Lancet Respiratory Medicine detailed the work.
“One third of the world’s population is currently infected with TB,” Purvesh Khatri, assistant professor of medicine and senior author of the paper, said. “Even if only 10 percent of them get active TB, that’s still three percent of the world’s population — 240 million people.”
In 2014, the World Health Organization challenged experts to develop better tests to find tuberculosis. About 9.6 million people, or three percent of the population, had TB in 2014, according to WHO estimates.
Old tests would use a skin prick test and interferon assays, but the method was not able to determine those with active or inactive TB. Another way to test is by using bacteria in sputum samples, though it is tough to get these samples from patients.
The new test will work on a regular blood sample. The test will work regardless of HIV, whether the TB is latent or active.