Quantifying the economic burden of zoonotic Salmonella in poultry using a stochastic modelling approach for the Netherlands, Belgium, and Denmark.

Zoonotic Salmonella remains a major target of control programmes in European poultry production, yet its economic burden at the animal production level is not well quantified across countries. This study aimed to develop an animal cost-of-illness (a-COI) framework and apply it to estimate the economic burden of zoonotic Salmonella infections in poultry populations under surveillance in the Netherlands, Belgium, and Denmark. The framework combined publicly available epidemiological data, economic inputs, and production-impact parameters to estimate direct tangible costs associated with surveillance, control, and eradication, as well as indirect tangible costs from production losses and revenues foregone due to excess mortality or culling. Uncertainty was propagated using Monte Carlo simulation, and results were additionally expressed as purchasing power parity (PPP)-adjusted estimates and per 100,000 birds. Median total tangible a-COI was estimated at €15.69 million/year (95% UI: €11.61 - 12.23 million) in the Netherlands, €4.39 million/year (€3.35 - 5.89 million) in Belgium, and €0.78 million/year (€0.69-0.89 million) in Denmark. Direct tangible costs accounted for the largest share of the burden in all three countries. PPP-adjusted results and size-standardised metrics showed the same cross-country ranking. Sensitivity analysis indicated that uncertainty was driven mainly by broiler excess mortality and production-performance parameters. This study introduces a standardized a-COI framework, designed to be broadly applicable across zoonotic diseases and animal species, and presents its first application to zoonotic Salmonella in poultry (broilers and laying hens), offering a transparent basis for future One Health economic assessments.