High Rates of Tuberculosis and Opportunities for Prevention among International Students in the United States

Foreign-born persons traveling on a student visa are not currently screened for tuberculosis on entry into the United States, despite residing in the United States for up to several years.

To characterize the risk of tuberculosis in international students entering the United States and to identify strategies for early diagnosis and prevention in this population.

Data were collected in 18 tuberculosis control jurisdictions in the United States. A cohort of 1,268 foreign-born patients of known visa status, diagnosed with active tuberculosis between 2004 and 2007, was used for analysis. Incidence rates were estimated on the basis of immigration data from study jurisdictions.

Tuberculosis was diagnosed in 46 student residents, providing an annual estimate of 308 cases nationally. The estimated tuberculosis case rate in student residents was 48.1 cases per 100,000 person-years (95% confidence interval, 35.6-64.8), more than twice that of the general foreign-born population. Students identified by tuberculosis screening programs were more likely to be diagnosed within 6 months of U.S. arrival (75 vs. 6%; P < 0.001), and those with pulmonary disease were less likely to have a positive sputum smear for acid-fast bacilli compared with those not screened (18 vs. 63%; P = 0.05). In unscreened students, 71% were diagnosed more than 1 year after U.S. arrival and only 6% were previously treated for latent tuberculosis infection.

The tuberculosis case rate in foreign-born students is significantly higher than in other foreign-born individuals. Screening this group after arrival to the United States is an effective strategy for earlier diagnosis of active tuberculosis.