Background: Approximately one-fourth of the global population is latently infected with Mycobacterium tuberculosis. An understanding of the burden of latent tuberculosis infection (LTBI) among immigrants compared with the general Korean population should be the first step in identifying priority groups for LTBI diagnosis and treatment. The study aimed to compute the age-standardized LTBI prevalence and predictors among immigrants with LTBI in South Korea.

Methods: In 2018, the Korea Disease Control and Prevention Agency implemented a pilot LTBI screening project for immigrants using a chest radiography and the QuantiFERON Gold In-Tube assay. A standardized prevalence ratio (SPR) was computed to compare the LTBI burden in immigrants and the general Korean population.

Results: During the duration of the project, a total of 8108 immigrants (5134 males and 2974 females) underwent LTBI screening. The SPR of 1.547 (95% confidence interval [CI] 1.468-1.629) in males and 1.261 (95% CI 1.177-1.349) in females were both higher than the Korean reference population. Furthermore, among the immigrants, those aged < 40 years and Korean diaspora visa holders had a higher SPR.

Conclusion: This study found a higher LTBI prevalence among immigrant population in South Korea compared to that in the general Korean population, and the SPR was higher among those aged < 40 years and the Korean diaspora. The findings can be used as baseline evidence for including immigrants in South Korea in the at-risk group with a priority need for LTBI screening and treatment.

Keywords: Immigrant screening; Standardized prevalence ratio; Tuberculosis screening.