Impact of Veterinary Antibiotic Use on Immune Modulation and Antimicrobial Resistance in Human Health : A Systematic Review and Meta-Analysis of Zoonotic Transmission Pathways

Sammanfattning

Antimicrobial resistance (AMR) poses a critical global health threat, with recent estimates indicating 4.95 million AMR-associated deaths in 2019. This systematic review and meta-analysis examined the relationship between veterinary antibiotic use and human health outcomes, focusing on transmission pathways and intervention effectiveness. Following PRISMA guidelines, five electronic databases (2010-2024) were systematically searched. Two independent reviewers screened studies, extracted data, and assessed quality using standardized tools. Random-effects meta-analysis synthesized findings, with heterogeneity assessed using I² statistics. Among 127 included studies, complete antibiotic restrictions were associated with a 15% reduction in resistance (95% CI: -18% to -12%, I²=92.3%). Growth promoter restrictions showed the largest effect (-30%, 95% CI: -42% to -17%, I²=98.5%). Environmental transmission was documented in 89% of relevant datasets, while direct contact transmission was confirmed in 92% of exposure-relevant sites. Geographic analysis revealed significant regional variations, with most evidence from Europe (n=139) and North America (n=39). Broad-spectrum interventions appear more effective than single-drug restrictions in reducing AMR, though complete bans may not be necessary for significant impact. Findings support a nuanced approach to antibiotic stewardship in agriculture, considering local contexts and specific agricultural practices. Future research should prioritize low-income settings and economic impact assessment. These findings have important implications for policy development and clinical practice, suggesting that effective AMR control can be achieved through targeted interventions rather than requiring complete antibiotic bans.