Salmonella spp. in Serbian poultry production (2020-2025): Retrospective trends and farmers' perceptions of biosecurity.

BACKGROUND

Salmonella enterica subsp. enterica remains a major zoonotic threat worldwide, with poultry products being a major source of human foodborne infections.

METHODS

A retrospective analysis of Salmonella spp. occurrence in Serbian poultry production was conducted using routine diagnostic data collected between 2020 and 2025. A total of 2453 samples from poultry farms, 147 from hatcheries and 3237 from broiler slaughterhouses were analysed. To complement the epidemiological investigation, a questionnaire was administered to 29 poultry farmers to assess difficulty associated with implementing measures from different biosecurity categories (BCs) and awareness of the economic consequences associated with Salmonella detection.

RESULTS

Salmonella spp. was detected in 2.9% of farm samples and 8.4% of slaughterhouse samples, whereas all hatchery samples tested negative. Across poultry categories, broilers showed the highest positivity rate (57/977, 5.8%), followed by layers (10/588, 1.7%) and breeders (4/741, 0.5%). Serotyping was available for a subset of farm isolates, with S. Enteritidis representing the most frequent serovar (83.3%). Generalised linear mixed-effects models identified seasonality as a significant predictor of Salmonella occurrence. 'Depopulation process', 'manure and carcass removal', 'biological vector control' and 'disease management' were perceived as most challenging BCs.

CONCLUSION

This study provides the first integrated assessment of Salmonella occurrence across multiple components of the Serbian poultry production chain, combining retrospective surveillance data with a farmer-based evaluation of biosecurity implementation. The findings identify critical points for Salmonella transmission and provide evidence to support targeted, context-specific biosecurity interventions.