Factors Influencing the Diagnosis and Treatment of Latent Tuberculosis among Contacts in Congregated Settings in Korea

BACKGROUND: This study aimed to compare the indicators (the rates of diagnosis, need for treatment, treatment initiation, and treatment completion) of management of latent tuberculosis infection (LTBI) in contacts and to identify the impact of active tuberculosis (TB) index case characteristics on the exposed population in congregated settings, such as schools, workplaces, and medical institutes. METHODS: The data of 8,648 clusters in the TB epidemiological investigation database between 2013 and 2016 were extracted and analyzed to evaluate the indicators and perform multilevel logistic regression (MLR) analyses to identify the factors affecting each indicator. RESULTS: The rates of total LTBI diagnosis, need for treatment, treatment initiation, and treatment completion were 15.2%, 10.2%, 69.4%, and 76.6%, respectively. After adjusting for other factors on MLR, the probability of diagnosis and need for treatment of latent TB in contacts was higher in most types of facilities than in schools. Conversely, treatment completion rates in these facilities were lower. Notably, the correctional institutions showed the highest odds ratio (OR) relative to school for LTBI diagnosis (OR, 6.37) and need for treatment (OR, 4.49) and the lowest OR for treatment completion (OR, 0.10). CONCLUSION: This study provided evidence for the implementation of latent TB control policies in congregated settings.