Blood test could improve TB diagnosis in developing nations

One-third of the world's population is currently infected with TB.
One-third of the world's population is currently infected with TB. | File photo

Stanford University School of Medicine researchers recently discovered a gene expression “signature” that can be seen in a simple blood test, making it more affordable and efficient to manage tuberculosis (TB).

The most recent statistics show that TB kills approximately 1.5 million people each year. Approximately 9.6 million people contract new TB infections every year. 

TB is difficult to diagnose, especially in countries that have limited resources and technologies. Current diagnostic methods use skin pricks and interferon assays. Unfortunately, these methods cannot distinguish between people who have active TB and people who have latent TB. Sometimes these tests even misdiagnose an HIV patient as having TB.

The recently discovered gene shows whether patients have active or latent TB. The study, published in Lancet Respiratory Medicine, shows there is no longer a need for expensive tests that gather sputum. Instead, a blood sample can be more accurate.

"One-third of the world's population is currently infected with TB,” Dr. 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 3 percent of the world's population -- 240 million people.”

This research is the result of a call from the World Health Organization, which has encouraged scientists to create more accurate diagnostic tests to detect active TB.

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