Alcohol Consumption of Male Tuberculosis Index Cases and Tuberculosis Transmission Among Social Contacts in Puducherry, India: A Cross-Sectional Analytical Study.

We aimed to compare the proportion of tuberculosis infection among social contacts of male tuberculosis Index case with and without alcohol use in the Puducherry district. A cross-sectional study using ego-centric approach was conducted between November 2023 and May 2024. A total of 713 social contacts of 106 male pulmonary tuberculosis index cases were enrolled, stratified by alcohol-use (AUDIT ≥ 8): 358 contacts from 45 alcohol-using cases and 355 from 61 non-alcohol-use cases. Social contacts were defined based on the frequency and duration of shared indoor exposure with index cases within the past three months. Tuberculosis infection was screened with Cy-Tb skin test (≥5 mm induration) at the third month of index case treatment. Univariate and multivariable analysis were conducted to identify factors associated with tuberculosis transmission. Among the 358 social contacts of alcohol-use index cases, 33.8% (n = 121; 95% CI, 29.1-38.8%) tested positive for tuberculosis infection, significantly higher than 21.7% (n = 77; 95% CI, 17.7-26.3%) among 355 contacts of non-alcohol-use cases. Regression analysis revealed that contacts of alcohol-using index cases (aOR = 1.6, p < 0.05), were significantly associated with tuberculosis infection. Alcohol-use among tuberculosis patients significantly increases the risk of tuberculosis infection in their social networks.