Carcass Hygiene Outcomes Associated with Hazard Analysis and Critical Control Point (HACCP) Implementation and Stage-Specific Verification in Pig Abattoirs in Taiwan, 2018–2025

In late 2020, Taiwan launched an official Hazard Analysis and Critical Control Point (HACCP) certification program for abattoirs. This study evaluated microbiological outcomes associated with program implementation using nationwide Salmonella surveillance data from pig abattoirs in Taiwan (2018–2025) together with stage-specific verification in the 12 abattoirs that had been certified under the program after an official on-site audit. Verification sampling covered three points on the slaughter line: before antimicrobial washing (Pre-CCP), after antimicrobial washing (CCP1, decontamination), and after chilling (CCP2). Among the 12 certified abattoirs, the Salmonella -positive rate was 6.7% during the pre-policy baseline period (2018–2020) and 2.9% during the implementation period (2021–2025), corresponding to a pooled relative risk of 0.43 (95% CI: 0.23–0.84; P = 0.0107). During the implementation period, the Salmonella -positive rate was significantly lower in the certified cohort than in non-HACCP abattoirs ( P < 0.0001). Stage-specific verification showed lower contamination at later processing stages: the pooled Salmonella -positive rate was 8.5% at Pre-CCP, 3.5% at CCP1, and 0.1% at CCP2. Median aerobic plate counts (APC) were 4.00 log 10 (CFU/cm 2 + 1) at Pre-CCP, 3.03 at CCP1, and 1.77 at CCP2, an overall difference of 2.23 log 10 units between Pre-CCP and CCP2, and median generic Escherichia coli ( E. coli ) counts were 0.59, 0.03, and 0.00, respectively. These findings indicate that official HACCP implementation was associated with improved carcass hygiene in the certified cohort and support the use of quantitative microbiological data for routine CCP verification under commercial slaughter conditions.