Prevalence of Latent Tuberculosis Infection and Willingness for Preventive Treatment among Household Contacts: A Prospective Observational Study from a Tertiary Centre, Karnataka, India

Introduction: Latent Tuberculosis Infection (LTBI) represents a state in which individuals are infected with Mycobacterium Tuberculosis (MTB) but do not exhibit active disease symptoms. Despite the absence of clinical manifestations, LTBI poses a significant public health challenge, as approximately onequarter of the world’s population is estimated to harbour latent infection. Household Contacts (HHCs) of individuals with active Tuberculosis (TB) are frequently exposed to MTB, leading to greater risk of developing LTBI due to shared living environments. Without treatment, 5-10% of individuals with LTBI may progress to active TB during their lifetime. Early identification and management of LTBI are critical to TB control and elimination efforts, highlighting the importance of effective screening and preventive therapy strategies. Aim: To determine the prevalence of active TB and LTBI among HHCs and to assess their willingness to initiate Tuberculosis Preventive Treatment (TPT), as well as treatment adherence and associated barriers. Materials and Methods: The prospective observational study was undertaken between April 2023 and January 2025. HHCs of active TB patients were enrolled after informed consent, and a structured questionnaire was used for data collection. Chest radiography, sputum microscopy, and Tuberculin Skin Test (TST) were carried out for screening. Willingness to initiate TPT, reasons for refusal, and adherence among those treated were documented. Data were analysed using Statistical Package for Social Sciences (SPSS) v20.0, and significance was set at a p-value threshold of 0.05. Results: A total of 264 HHCs were evaluated. Females were 136 in number, constituting 51.5% of the population. The mean age was 34.55±16.45 years, and the mean Body Mass Index (BMI) was 22.29±4.16 kg/m². Active TB was diagnosed in 2 (0.76%) participants, and LTBI in 43 (16.3%). A total of 213 (81.3%) HHCs showed willingness to initiate TPT, though completion was observed in only 77 (37.2%). The primary reason for noninitiation was misconception about the disease and treatment. Conclusion: The present study revealed 16.3% LTBI prevalence within the HHCs population and low completion rates of TPT despite high initial willingness, indicating gaps in adherence. Targeted education and strengthened programmatic support are crucial to enhance LTBI management and advance TB elimination efforts.