Assessing the effect of on-farm and abattoir interventions in reducing human salmonellosis from pig meat consumption in the EU

Abstract

Pigs are commonly infected with Salmonella spp. at the slaughterhouse, and the consumption of pig meat is hypothesised to be an important contributor to human salmonellosis. The European Union (EU) will shortly set targets for the reduction of Salmonella in pigs at slaughter for each Member State (MS), and each MS is expected to put in place a National Control Plan (NCP) in order to achieve their targets. If MSs are to realise their targets then practical interventions that consistently work must be identified. As part of the evidence base for the development of NCPs, a Quantitative Microbiological Risk Assessment (QMRA) was funded to support the scientific opinion required by the EC from the European Food Safety Authority, which was subsequently adopted by the BIOHAZ panel. Here we describe how the baseline model was modified to simulate the effect of both on-farm and abattoir interventions, and the resultant reductions on the predicted number of human Salmonella cases attributable to pig meat consumption in an EU MS. We present the results from two case study MSs with differing slaughter pig Salmonella prevalence and production systems to exemplify the differences that interventions have between MSs. In the two MSs, both on-farm and abattoir interventions were predicted to be able to produce a significant reduction in salmonellosis attributable to pig meat consumption. Anal bunging of the carcass during processing was shown to be the most effective intervention mechanism in reducing human illness. Some intervention mechanisms were ineffective in reducing human illness, including increased cleaning and disinfection (C&D) at the farm and logistic slaughter.

A Quantitative Microbiological Risk Assessment for Salmonella transmission in pigs in individual EU Member States

“…Table 1: Baseline results from the QMRA: mean probabilities of illness by eating one serving of pork cuts, minced meat or fermented sausage in the 4 case study MSs. A key part of the QMRA was the investigation of interventions (for further information see Hill et al 2011b). From the intervention analysis it was concluded that certain farm intervention mechanisms (such as reducing the susceptibility of the pig to infection, possibly by vaccination or organic acids) may produce significant changes in the slaughter pig prevalence, although evidence that specific farm interventions consistently work was sparse.…”