Abstract
BACKGROUND: In 2010, Mexico was the most common (22.9%) country of origin for foreign-born persons with tuberculosis in the United States, and overall trends in tuberculosis morbidity are substantially influenced by the Mexico-born population. OBJECTIVES: To determine the risk of tuberculosis disease among Mexico-born persons living in the United States. METHODS: Using data from the U.S. National Tuberculosis Surveillance System and the American Community Survey, we examined tuberculosis case counts and case rates stratified by years since entry into the United States and geographic proximity to the United States-Mexico border. We calculated trends in case rates over time measured by average annual percent change. RESULTS: The total tuberculosis case count (-14.5%) and annual tuberculosis case rate (average annual percent change -5.1%) declined among Mexico-born persons. Among those diagnosed with tuberculosis less than 1 year since entry into the United States (newly arrived persons), there was a decrease in tuberculosis cases (-60.4%), no change in tuberculosis case rate (average annual percent change of 0.0%), and a decrease in population (-60.7%). Among those living in the United States for more than 5 years (non-recently arrived persons), there was an increase in tuberculosis cases (+3.4%), a decrease in tuberculosis case rate (average annual percent change of -4.9%), and an increase in population (+62.7%). In 2010, 66.7% of Mexico-born cases were among non-recently arrived persons, compared with 51.1% in 2000. Although border states reported the highest proportions (>15%) of tuberculosis cases that were Mexico-born, the highest Mexico-born-specific tuberculosis case rates (>20/100,000 population) were in states in the eastern and southeastern regions of the United States. CONCLUSIONS: The decline in tuberculosis morbidity among Mexico-born persons may be attributed to fewer newly arrived persons from Mexico and lower tuberculosis case rates among non-recently arrived Mexico-born persons. The extent of the decline was dampened by an unchanged tuberculosis case rate among newly arrived persons from Mexico and a large increase in the non-recently arrived Mexico-born population. If current trends continue, tuberculosis morbidity among Mexico-born persons will be increasingly driven by those who have been living in the United States for more than 5 years.