Tuberculosis
Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis that primarily affects the lungs but can spread to other organs, transmitted through airborne droplets when an infected person coughs, speaks, or sneezes. Globally, TB remains the deadliest infectious disease in the world, killing more than 1 million people annually. In the U.S., TB was long considered a disease in decline, but recent years have reversed that trend. After surging to 10,347 cases in 2024 — the highest count since 2011 and an 8% increase over 2023 — provisional CDC data show 10,260 TB cases reported in 2025, a modest 1% decline but still well above pre-pandemic levels. The vast majority of U.S. TB cases (77%) occur in people born outside the country, with a rate of 15.4 per 100,000 among non-U.S.-born individuals compared to just 0.8 per 100,000 among U.S.-born individuals. One-third of all cases involve adults aged 25 to 44. A critical complicating factor is latent TB infection — in which the bacteria remain dormant and non-contagious — which affects an estimated 13 million Americans and can reactivate when the immune system is weakened. Drug-resistant TB strains pose an increasing global concern, and eliminating TB in the U.S. requires a dual strategy of treating active disease while identifying and treating latent infections in high-risk populations.
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