Abstract:

Objective: To analyze the status of latent tuberculosis infection (LTBI) among close contacts of patients with active pulmonary tuberculosis (PTB) and to identify associated risk factors, thereby providing scientific evidence for formulating screening strategies and intervention measures for close contacts. Methods: In accordance with the enrollment criteria, close contacts of patients with active PTB who were newly diagnosed and registered for treatment at the Tianjin Center for Tuberculosis Control and Prevention in 2024 were recruited as research subjects. The data of the subjects were collected from the Surveillance Report Management System, a subsystem of the China Information System for Disease Control and Prevention, and the initial diagnosis registration system of the outpatient department. A total of 289 close contacts were confirmed based on medical records and the outpatient registration data. Relevant information on demographic characteristics, duration of exposure, number of contacts, and tuberculin skin test results was collected using structured questionnaires and “PPD registration book”. Binary logistic regression model was used to analyze the influencing factors of LTBI. Results: Among the 289 close contacts, 201 cases were diagnosed with LTBI, with an LTBI prevalence of 69.55%. Logistic regression analysis indicated that close contacts aged 30-59 years (OR=4.337, 95%CI: 1.609-11.687), spouse of the index patients (OR=2.471, 95%CI: 1.020-5.989) and the bacteriologically positive index cases (OR=2.249, 95%CI: 1.165-4.342) were independent risk factors for LTBI among close contacts. Conclusion: Close contacts are the key target population for LTBI screening. Priority should be given to close contacts aged 30-59 years, and the spouses of the index patients, and those with long-term exposure to bacteriologically positive tuberculosis patients. Targeted prevention and control interventions should be implemented in a timely manner.

Key words: Tuberculosis, pulmonary, Contact tracing, Factor analysis, statistical