Campylobacter contamination in broiler carcasses and correlation with slaughterhouses operational hygiene inspection

This study investigates factors associated with Campylobacter contamination of broiler carcasses, using survey data collected from nine Belgian slaughterhouses in 2008 in accordance with a European Union baseline study. Campylobacter were detected in 51.9% (202/389) (95% confidence interval, 46.8%-56.9%) of broiler carcasses. Campylobacter concentration was <10 CFU/g in 49.6% of carcasses, while 20.6% were contaminated with ≥ 1000 CFU/g. The mean Campylobacter concentration, as calculated by maximum likelihood estimation for left-censored data, was 1.8 log(10) CFU/g, with a standard deviation of 1.9 log(10) CFU/g. There was statistically significant variation among slaughterhouses in prevalence and concentrations of Campylobacter in their sampled carcasses. Campylobacter prevalence (but not concentrations) was positively associated with increase in broilers age. Both Campylobacter prevalence and concentration were significantly higher in carcasses sampled during June and September (but not in July and August) than carcasses sampled in January. We also investigated the correlation (Spearman's rank correlation test) between the scores of official control inspections and Campylobacter prevalence for eight out of the nine slaughterhouses. The control inspections were routinely performed by the Belgian Federal Agency for the Safety of the Food Chain, and the concluded inspection scores were used as a general numerical indicator for the status of operational hygiene and quality of management in the slaughterhouses. Ranking of slaughterhouses based on their inspection scores was statistically correlated (Spearman's correlation coefficient = 0.857) with their ranking based on prevalence of Campylobacter. In the present study we demonstrate how the outcomes from a routine baseline survey could be coupled with other readily available data from national control authorities in order to enable a better insight over Campylobacter contamination status in broiler slaughterhouses. Findings from this work call for subsequent in-depth investigations on technical and hygiene management factors that could impact Campylobacter contamination across broiler slaughterhouses.