US researchers on Monday said they have developed a fast blood test for tuberculosis that could speed diagnosis and treatment of the serious and sometimes fatal bacterial infection.
One of the oldest known diseases, tuberculosis, or TB, has killed an estimated billion people over the past two centuries.
A bacterial infection that attacks the lungs and can cause coughing, fever, night sweats and weight loss, TB is one of the top 10 causes of death worldwide today.
Some 10.4 million people were sickened with TB in 2015, and 1.8 million died from the disease, according to the World Health Organization.
However, diagnosing TB remains complicated.
"In the current frontlines of TB testing, coughed-up sputum, blood culture tests, invasive lung and lymph biopsies, or spinal taps are the only way to diagnose TB," said Tony Hu of Arizona State University's Biodesign Institute, who led the effort to develop the new test.
"The results can give false negatives, and these tests are further constrained because they can take days to weeks to get the results."
The new test "outperforms all others currently on the market" and can be completed in hours, researchers said in a statement.
It is also the first to measure the severity of active TB infections by looking at two proteins in the blood -- called CFP-10 and ESAT-6 -- that TB bacteria release only during active infections.
Its accuracy was about 92 percent, regardless of whether or not patients were also infected with HIV, which can require more complicated testing for TB.
The test is not yet available to the public and its cost has not yet been determined.
A report describing the test was published in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.