Association Between Socioeconomic Status and Antimicrobial Use Patterns Among Broiler Farmers in Kilimanjaro and Mwanza Regions, Tanzania

Abstract

Antimicrobial resistance (AMR) poses a critical global health threat, with agricultural antimicrobial use (AMU); particularly in poultry systems; representing a major contributor, yet evidence on how socioeconomic and contextual factors jointly shape AMU patterns in low-resource settings remains limited. This study investigated the association between socioeconomic characteristics and AMU practices among broiler farmers in Tanzania’s Kilimanjaro and Mwanza regions, examining both prevalence and frequency of antimicrobial application. Using a mixed-methods cross-sectional design, we surveyed 246 broiler farmers and conducted qualitative interviews to contextualize quantitative findings. Results revealed significant regional disparities: Mwanza exhibited substantially higher AMU prevalence (91.1% vs. 81.3%; χ²=10.5, p<0.001) and more frequent usage patterns (daily use: 35.0% vs. 29.3%) compared to Kilimanjaro. Training emerged as the strongest protective factor, reducing AMU odds by 95.6% (OR=0.044, 95% CI: 0.004–0.458; p=0.011) and decreasing usage frequency (OR=0.149, 95% CI: 0.028–0.780; p=0.024), though qualitative findings revealed limited training accessibility. Larger family size similarly reduced frequent AMU (OR=0.599, 95% CI: 0.424–0.847; p=0.0037). Critically, significant interaction effects revealed that education combined with training unexpectedly increased both AMU likelihood (OR=4.01; p=0.048) and frequency (OR=2.20; p=0.046), suggesting a “competency paradox” where knowledge may foster overconfidence in autonomous antimicrobial administration. Similarly, farming experience interacting with larger flock size increased usage frequency (OR=1.20; p=0.035), indicating that production intensification pressures may override experiential caution. These findings demonstrate that AMU practices emerge from complex intersections of socioeconomic position, knowledge acquisition, and structural constraints rather than from individual factors in isolation. Effective AMU stewardship in Tanzanian broiler systems therefore requires contextually-adapted, socioeconomic-responsive interventions that address not only farmer education but also the institutional, regulatory, and economic environments shaping antimicrobial dependence, including gender-sensitive extension services, strengthened veterinary oversight, and production system modifications that reduce disease pressure.