Long a dream, it's now real: a fast and accurate TB test that doesn't need phlegm

A scanning electron micrograph of Mycobacterium tuberculosis bacteria, which cause TB. BSIP/Universal Images Group via/Getty Images hide caption toggle caption BSIP/Universal Images Group via/Getty Images TB or not TB? That has been the question for nearly 150 years, when Dr. Robert Koch first identified the rod-shaped bacterium that causes tuberculosis. This serious respiratory illness is currently the world's deadliest infectious disease , killing more than a million people a year. …