Tuberculosis in the South America's homeless: a systematic review of social determinants, control strategies and health equity

Introduction Tuberculosis (TB) remains a major public health problem in South America, disproportionately affecting vulnerable populations, such as the homeless population (HP). Objective To synthesize, through a systematic review with meta-synthesis, the scientific evidence on the relationship between tuberculosis and its social, individual, and programmatic determinants in the HP in South America, highlighting factors associated with treatment abandonment and mortality. Methods Scientific articles were searched in PubMed, EMBASE, LILACS, SciELO, Web of Science, and Cochrane databases, published in Portuguese, English, or Spanish between 2013 and 2023. Study selection was conducted independently by three reviewers, with consensus reached by a fourth when necessary. The process followed the protocols of the Cochrane Collaboration and the PRISMA flowchart, resulting in the inclusion of 27 studies. Results The most frequent determinants were lack of social protection (85%) and extreme poverty (75%), both associated with high rates of treatment abandonment (average of 36%) and mortality (average of 14%). Reduced use of Directly Observed Therapy (DOT) and regional inequalities emerged as critical factors. The meta-synthesis indicated that alcohol and drug users had a 2.3 times higher risk of treatment abandonment, while TB-HIV coinfection increased mortality by up to threefold. Conclusion The vulnerability of the HP to TB is strongly linked to social and programmatic factors. Intervention strategies should prioritize social protection, expansion of DOT, intersectoral policies, and approaches tailored to regional contexts in order to reduce inequalities and promote health equity.