Latent Tuberculosis Infection Screening in Immigrants to Low-Incidence Countries: A Meta-Analysis

Immigration from regions with a high incidence of tuberculosis (TB) has slowed the decline of TB in low-incidence regions. Targeted screening of new immigrants and treatment for latent TB infection (LTBI) is needed to reinvigorate this decline. This meta-analysis compares LTBI diagnostic tests by positive test prevalence and proportion of positive tests by TB incidence. A systematic literature search was performed and data extracted based on tuberculin skin test (TST) and/or interferon-gamma release assay (IGRA) use in immigrants. For the eight studies performing tests concurrently, data were compared by positive tests and concordance, while other studies comparing individual tests were analyzed based on demographic factors. Data were analyzed via meta-analysis. Forty-five studies with a combined sample size of 93,249 individuals were included in the analyses, 2206 of which were from the eight concurrent studies. Odds of a positive TST were significantly higher than an IGRA (odds ratio 1.46; 95 % confidence interval 1.07-2.01) and test agreement was moderate. Proportion of positive TST and IGRA tests increased with TB incidence, although not linearly. TST and IGRA data relating to immigrants are lacking, especially long-term follow-up and comparative data. Further data are urgently needed to determine TB risks after immigration, long-term TB development, and treatment outcomes.