Abstract: Objective To investigate the prevalence and influencing factors of latent tuberculosis infection (LTBI) among household close contacts of ethnic minority patients with pulmonary tuberculosis in Sichuan province, and to provide evidence for developing targeted LTBI intervention strategies for ethnic minority groups. Method Participants were household close contacts of ethnic minority patients with etiologically confirmed pulmonary tuberculosis admitted to Chengdu Public Health Clinical Center from June to December 2024. All participants received LTBI screening and questionnaire surveys, and were divided into LTBI group and non-LTBI group according to screening results. General demographic data, household living conditions, living habits and clinical data of index cases were compared between the two groups. Binary logistic regression model was used to analyze the independent influencing factors of LTBI. Result A total of 168 household close contacts were included. The overall LTBI prevalence was 39.3% (66/168), and only 2 (3.0%) LTBI-positive participants were willing to receive preventive treatment. Multivariate logistic regression analysis indicated that other occupations (OR=0.160, 95%CI: 0.047-0.553) and unemployed/retired status (OR=0.162, 95%CI: 0.050-0.529) were independent protective factors against LTBI. Per capita living area less than 50m² (OR=4.412, 95%CI: 1.665-11.689), consanguineous kinship with index cases (OR=2.931, 95%CI: 1.284-6.687), and index cases with pulmonary cavities involving more than 2 lung fields (OR=6.013, 95%CI: 1.641-22.033) were independent risk factors for LTBI. Conclusion Household close contacts of ethnic minority pulmonary tuberculosis patients in Sichuan province have a high LTBI prevalence and extremely low acceptance of preventive treatment, with a high risk of active tuberculosis. Contacts engaged in other occupations or being unemployed/retired have a lower risk of LTBI. In contrast, those who are consanguineous relatives of index cases, live in per capita living space below 50 m², or have contact with index cases with pulmonary cavities involving more than 2 lung fields are at higher risk of LTBI, and should be regarded as the key high-risk population for LTBI prevention and control.

Key words: Latent tuberculosis infection, Influencing factor, Pulmonary tuberculosis, Ethnic minorities, Household close contacts