Predictors of positive tuberculin skin test results in a jail population

The purpose of this analysis was to determine the prevalence and predictors of positive tuberculin skin tests (TSTs) in a jail population. TST results and demographic data were obtained for 996 male inmates of a Connecticut jail who were tested following identification of a case of multidrug-resistant Mycobacterium tuberculosis (MDR-TB). Inmates were predominantly young (median age, 26 years) and Black (51%) and were born in the United States (96%). Overall 109 (11%) inmates had positive TST results. TST positivity was strongly associated with being born outside the United States (adjusted odds ratio [aOR] = 11.3, 95% confidence interval [95% CI] 4.9-25.8), being Puerto Rican born (aOR = 3.7, 95% CI 1.9-7.4), and increasing age (15-24 years aOR = l [referent]; 25-34 years aOR = 2.1 95% CI 1.2-3.5; 35-44 years aOR = 4.3 95% CI 2.4-7.7; > or = 45 years aOR = 6.4 95% CI 2.8-14.6). The combination of being U.S.-born and Black was also associated with increased rates of positive TSTs. The prevalence of TST positivity was > 10% for all age groups of inmates born outside the United States or Puerto Rico and for Puerto Rican-born inmates aged > or = 25 years and U.S.-born inmates aged > or = 35 years. Analysis of routinely collected TST data allows predictors of TST positivity to be identified and may help determine population subgroups for whom anergy screening and preventive therapy should be considered.