In 2011–2012, 6,328,000 foreign-born persons in the United States were estimated to have latent tuberculosis infection (LTBI). Estimates of LTBI prevalence by subpopulation are needed to facilitate testing and treatment to prevent tuberculosis (TB) disease. Studying subpopulations by race/ethnicity would improve understanding of LTBI burden in the United States.
Quantiferon Gold In-tube (QFT-GIT) blood tests were performed among civilian, noninstitutionalized persons > 6 years of age as part of the 2011–2012 National Health and Nutrition Examination Survey (NHANES). LTBI prevalence and 95% confidence intervals (CI) were calculated by adjusting for complex survey design and QFT-GIT sensitivity and specificity. Reactivation rates were calculated using NHANES LTBI prevalence and the number of TB cases reported to the National TB Surveillance System that were not associated with recent transmission. All calculations used U.S. Census Bureau population. We compared three foreign-born subpopulations: all foreign-born; non-Hispanic Asian, non-Hispanic black or Hispanic; and non-Hispanic whites.
QFT-GIT results were available for 1,955 foreign-born persons. LTBI prevalence was 19.1% (95% CI 15.0, 23.9) among foreign-born non-Hispanic Asian, non-Hispanic black or Hispanic subpopulation compared to 6.3% (1.9, 18.9) among foreign-born non-Hispanic whites and 16.9% (13.1, 21.5) among all foreign-born. The LTBI reactivation rate among foreign-born non-Hispanic whites was 0.062 (0.021, 0.203) per 100 person-years; reactivation rates per 100 person-years were similar for all foreign-born (0.088 [0.069, 0.114]) and non-Hispanic Asian, non-Hispanic black or Hispanic subpopulation (0.091 [0.073, 0.116]).
Although LTBI prevalence was higher among the foreign-born non-Hispanic Asian, non-Hispanic black or Hispanic subpopulation than the foreign-born non-Hispanic white subpopulation the difference was not statistically significant at the 0.05 level. However, due to small sample size, estimates for foreign-born non-Hispanic whites should be interpreted with caution. These results may help guide LTBI targeted testing and treatment.
R. Yelk Woodruff,
S. Marks, None
T. Navin, None
R. Miramontes, None