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

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 (CD Mousing et al. 1997); however, the success of these programs is varied (Nielsen et al. 2001, BPEx 2009), In addition, it is not a easy task to attribute reductions in human cases to a control program due to the natural variation in foodborne cases that would occur regardless of any intervention. If MSs are to meet their targets, and the EU is to realise its aim of reducing human salmonellosis attributable to pig meat consumption, then practical interventions (across the food chain) that work consistently and efficiently must be identified. The most effective interventions are likely to differ between MSs, due to factors such as differing management practices or production processes involved in producing a MS’s commonly consumed pig meat products. Therefore, as part of the evidence base for the development of NCPs in individual MSs, a QMRA was funded to support the scientific opinion required by the EC from the European Food Safety Authority. As such, the main aim of this QMRA was to assess the effectiveness of interventions implemented on-farm and at the abattoir and how this may vary across EU MSs. Therefore the baseline model (EFSA 2010) was modified to describe the effect of both on-farm and abattoir interventions and the resultant reductions (if any) on the predicted number of human Salmonella cases in an EU MS attributable to the consumption of 3 pig meat products (pork chops, minced meat and fermented sausage). We present the results from two case