C57-18 Beyond the Patient: Household Transmission and the Hidden Reservoir of Tuberculosis in Rural Philippines - A Prevalence Study

Abstract Rationale Globally, there is a 41-53% risk of active and latent tuberculosis (TB) among household contacts of TB patients.In Southeast Asia, it was 21% while 69% was recorded in the Philippines. This study aims to validate the findings and to generate context-specific data for effective public health strategies and interventions Methods This is a descriptive cross-sectional research design to determine the prevalence of active and latent TB among household contacts of TB-treated cases in Leganes, Philippines. The target population will consist of household contacts of individuals who have completed TB treatment from 2023-2025. Results There were 382 household contacts of tuberculosis(TB) patients to determine prevalence and risk factors. The mean age was 38.5 years (±21.0) and was predominantly female (67%, n = 250). The primary outcomes revealed a 4.2% prevalence of Active TB (n = 16, 95% CI: 2.5%-6.9%) and a 13.9% prevalence of Latent TB Infection (LTBI) (n = 53, 95% CI: 10.7%-17.8%).A comparative analysis across Active TB (n = 16), LTBI (n = 53), and No TB (n = 295) groups identified significant demographic and clinical differences. The Active TB group was significantly older (mean age 57.4 years) compared to the LTBI (41.6 years) and No TB (36.1 years) groups (p < 0.001). Several risk factors were significantly associated with TB status. Tobacco use was markedly higher among the Active TB group (50%) compared to the LTBI (10%) and No TB (13%) groups (p = 0.005). Furthermore, a prior TB diagnosis (p = 0.008) and the presence of an autoimmune disease (p = 0.007) were significantly associated with TB status. Active TB group reported significantly fewer household members (mean 3.1) than the No TB group (mean 4.1) (p = 0.012). Factors, such as sex (p = 0.455) and years lived with the patient before diagnosis (p = 0.064), did not show a statistically significant association. Findings reveal a significant burden of TB among household contacts, with a 4.2% prevalence of active disease (95% CI: 2.5%-6.9%) and a 13.9% prevalence of latent infection (95% CI: 10.7%-17.8%). This confirms that household contacts are a critical high-risk group for TB transmission and progression. Conclusion The analysis identifies clear, actionable risk factors. Targeted screening and prevention programs should be prioritized, with a particular focus on contacts who are older (mean age 57.4 for active TB), use tobacco (50% of active TB group), or report a prior TB diagnosis or autoimmune disease. The high prevalence rates found in this study strongly support the need for robust contact tracing and screening protocols to interrupt transmission and manage TB effectively within this vulnerable population. This abstract is funded by: None