FRONTLINE TB Silent Killer ADD Aired: 03/25/201401:23:41Rating: NR Tuberculosis was once thought to be a disease of the past. But with virulent new drug-resistant strains emerging faster than ever, TB -- passed simply by a cough or a sneeze -- is the second leading cause of death from an infectious disease on the planet. In TB Silent Killer, FRONTLINE presents an unforgettable portrait of the lives at the pandemic's epicenter.