Assessment of process hygiene criteria in poultry slaughterhouses: A comparative analysis of own-checks and official controls in Northeast Italy (2021-2023).

Process hygiene criteria (PHC) for Campylobacter and Salmonella provide essential guidance on hygiene standards for poultry processing at slaughterhouses. Data collected by Member States (MSs) in Europe revealed inconsistencies between official verification and internal monitoring results, highlighting the need for a comprehensive investigation to uncover the reasons behind these discrepancies. This study investigated PHC in relation to operational factors at nine poultry slaughterhouses, integrating production characteristics and epidemiological surveillance data from a representative sample of supplying farms. The analysis is based on microbiological testing results collected between 2021 and 2023. PHC were monitored at regular intervals, creating a "moving window" of data to assess hygienic performance over time. The findings indicated that samples tested by competent authorities (CAs) showed higher prevalence rates of Campylobacter (27.6 %) and Salmonella (30.7 %) compared to those tested by food business operators (FBOs) (13.0 % and 8.7 %, respectively). However, statistically significant differences between paired observations (P < 0.05) were detected only in four high-throughput slaughterhouses. Six of the nine slaughterhouses face challenges in meeting the hygiene standards established by EC Regulation 2073/2005, with recurring non-compliance over three years, representing 17.0 % to 82.0 % of their total operational time. Serotyping of Salmonella isolates identified a high prevalence of S. Infantis (61.7 %), also prevalent in farm samples (72.0 %), frequently linked to human cases related to poultry meat in the region, underscoring its public health importance. The study highlights the importance of robust sampling protocols for comparative assessments by FBOs and CAs, alongside the need for continuous improvement in hygiene management. Discrepancies between FBO and CA sampling results, as reported by European Food Safety Authority (EFSA), in this study are largely attributed to the lower sampling frequency employed by CAs, which likely captures only a fraction of the microbial variability. Recurrent breaches of PHC underscore the ineffectiveness of current interventions in controlling microbial loads. These findings emphasize the need for comprehensive control measures throughout the production chain, including surveillance of emerging serovars and antimicrobial resistance monitoring.