Childhood Tuberculosis Following Household Exposure: Risk Factors and Clinical Outcomes from a Retrospective Cohort

Background: Tuberculosis (TB) remains a major cause of morbidity and mortality, with children primarily infected through close contact with adults. Data on household transmission in children in Türkiye are limited.Objective: This study aimed to determine the prevalence of latent t.u.berculosis infection (LTBI) and active TB disease among pediatric household contacts of adults with pulmonary multidrug-resistant (MDR) or drug-susceptible (DS) TB and identify risk factors associated with TB infection.Methods: This retrospective study included children (0–18 years) exposed to adult pulmonary TB at a tertiary center (2018–2024). Demographic, clinical, and diagnostic data were collected. Pediatric cases were classified as latent or active TB, and index case resistance as MDR or DS. The risk factors for active TB were evaluated.Results: A total of 124 household contacts were evaluated. The median age of the contacts was 111 months (IQR 47-151), and 65 (52.4%) were female. Bacillus Calmette-Guérin (BCG) coverage was 92.7%. LTBI was detected in 7 (5.6%) and active TB in 11 (8.8%) children. The absence of BCG vaccination (p = 0.027) and longer time to presentation (p = 0.002) were significantly associated with TB. Exposure to an MDR-TB index case significantly increased TB risk (42.9% vs 6.9%, p = 0.016). On multivariate analysis, MDR-TB contact (OR: 8.5; 95% CI: 1.39–52.4) and lack of BCG vaccination (OR: 6.3; 95% CI: 1.09–36.2) were independent predictors of disease.Conclusion: A substantial proportion of pediatric household contacts of TB patients developed infection or disease, with delayed evaluation, MDR-TB exposure, and absence of BCG vaccination significantly increasing the risk of progression.