Systematic review and meta‐analysis of the impact of decontamination interventions on the prevalence and concentration of Salmonella in broiler chickens during primary processing

Systematic review and meta‐analysis aggregate quantitative data from different studies into unified effect size estimates with better statistical power in risk assessment model parameterisation. This study uses systematic review and meta‐analysis to estimate Salmonella decontamination during broiler slaughter from scalding to post‐chilling, with meta‐regression applied to explore modifier variables. Data from 161 studies published between 1998 and 2022 was extracted from thirty‐five articles identified in the systematic review process with meta‐analysis and meta‐regression performed using the metafor package (version 2.0‐0) in R statistical environment (version 3.6.0). The analysis revealed carcass wash (1.31 log 10 CFU/carcass reduction in odds; P < 0.01) and chilling (121.50% reduction in relative risk; P < 0.01) had significant reduction on Salmonella concentration and prevalence, respectively. Chemical additives reduced the concentration (0.98 log 10 CFU/carcass; P < 0.01) and prevalence (64.74% relative risk; P < 0.01) but the efficacy of physical methods was not conclusive. Application of decontaminants through immersion was superior (0.90 log 10 CFU/carcass; P < 0.01) to spraying (0.72 log 10 CFU/carcass; P < 0.01). Adjusting the pH sequentially of electrolysed water, acetic acid and trisodium phosphate reduced the odds of Salmonella concentration by more than 2 log cycles and the relative risk by more than 100%. The results provide trends in the concentration and prevalence of Salmonella during the broilers slaughter process with application of decontamination interventions and provide a basis for control decision‐making and quantitative microbial risk assessment.