Long-term risk of tuberculosis among foreign-born persons in the United States

Context.-Cases of tuberculosis (TB) in the United States have declined for 4 consecutive years, but cases among foreign-born persons account for an increasing percentage. Objective.-To describe the risk of tuberculosis among foreign-born persons with respect to their length of residence in the United States. Design.-Cross-sectional analysis of national surveillance data. Setting.-The United States. Patients.-All verified TB cases reported to the Centers for Disease Control and Prevention between 1986 and 1994. Main Outcome Measure.-Stratum-specific incidence rates of TB by age, place of birth, length of residence, age at arrival in the United States, or combinations of these variables. Results.-Several groups of persons from countries with a high prevalence of TB had incidence rates higher than 20 per 100 000 person-years more than 20 years after arrival. Among long-term residents, those who arrived in the United Stales after their fifth birthday had incidence rates of TB 2 to 6 times higher than those of similar age who arrived before their fifth birthday. A total of 45% of the TB cases were among persons younger than 35 years and an additional 18% were among persons who arrived in the United States before their 35th birthday. Conclusions.-Imported Mycobacterium tuberculosis infection (active or latent) is responsible for most TB cases among foreign-born persons in the United States. Detection of active cases among recent arrivals is the main priority in these populations, but many cases were in persons who arrived in the United States before the age of 35 years that could potentially have been avoided with preventive therapy. Elimination of TB in the United States may not be feasible using available diagnostic and treatment modalities without increased efforts to address the global burden of this disease.