CDC Warns Large Tuberculosis Outbreaks Doubled in US Since Mid-2010s

Large tuberculosis (TB) outbreaks in the country have surged sharply in recent years, doubling between 2017 and 2023, according to new data published by the Centers for Disease Control and Prevention (CDC) in the Morbidity and Mortality Weekly Report.Researchers identified 50 large outbreaks—defined as 10 or more related cases within a three‑year period—across 23 states, up from just 24 outbreaks recorded from 2014 to 2016.The outbreaks accounted for 1,092 cases out of nearly 62,000 TB cases reported during the seven‑year period. While the U.S. continues to have one of the lowest TB incidence rates globally, the CDC says the rise in large outbreaks signals persistent transmission within close‑contact settings, particularly among people facing social and economic instability.What To KnowThe CDC found that nearly 80 percent of people involved in large outbreaks were U.S.-born, a dramatic contrast to the broader TB population, where only 26 percent of cases occur in U.S.-born individuals. Outbreak‑associated patients were also far more likely to experience substance use, 27 percent vs. 12 percent, homelessness, 9 percent vs. 5 percent, or incarceration 11 percent vs. 3 percent—factors that increase exposure risk and complicate treatment.Children and younger adults were disproportionately affected, according to the data with, 15 percent