Tuberculosis screening in the federal prison system: an opportunity to treat and prevent tuberculosis in foreign-born populations.

Abstract

Despite recent success in tuberculosis (TB) control efforts in the United States, marked declines in TB case rates have not been observed in foreign-born populations. Because foreign-born populations are becoming more important for targeted national TB control efforts, the Federal Bureau of Prisons (BOP) reviewed inmate medical data to evaluate risk factors associated with Mycobacterium tuberculosis infection and active TB disease. To improve screening strategies, BOP implemented chest radiograph screening for all inmates entering a federal detention center in San Diego, California. Tuberculin skin test (TST) data from an approximated intake cohort of inmates entering the system from February 1 to June 30, 1999, were analyzed to assess risk factors for M. tuberculosis infection among inmates entering federal prisons. The most recent case reports of inmates diagnosed with TB disease were reviewed. All inmates entering a San Diego detention facility from July 1 to December 31, 1998, were screened for TB by symptom review, TST, and chest radiographs. System-wide, foreign-born inmates were 5.9 times more likely to have a positive TST than US-born inmates, and accounted for 60% of recently diagnosed TB cases. Chest radiograph screening of all inmates entering the San Diego facility reduced exposure time to active TB cases by 75%, but TB incidence remained unchanged. The high prevalence of M. tuberculosis infection and TB disease among foreign-born inmates entering the federal prison system presents a strategic opportunity to provide preventive therapy to a high-risk population and to identify contagious cases that might elude traditional public health efforts. Universal chest radiograph screening was no more sensitive than TST for detecting active TB cases among newly incarcerated foreign-born inmates with a high prevalence of TB infection, but the screening reduced potential TB exposures through rapid identification of contagious cases.