In the present mandate EFSA was asked, by the European Commission (EC), to carry out a quantitative risk assessment and evaluate: the relative contribution of different meat categories to cases of food-borne Salmonella infections in humans, taking into account the occurrence of the pathogen in the food chain, risk factors, food production flows and food preparation and consumption habits. Following discussion with the EC, it was clear that QMRA was only one of several methods available for answering the ToR. In addition it was found that the questions were very broad and that data gaps would limit the possibilities for a complete answer to the questions. The WG agreed that the mandate should be pursued through focusing on different approaches for source attribution of human salmonellosis and the results obtained so far from such studies. Different MS use different approaches for source attribution of human salmonellosis, e.g. analysis of outbreak data, analytical epidemiology, microbial subtyping, comparative exposure assessment, and structured expert opinion. Each method of source attribution has different strengths and weaknesses and addresses different points in the food chain. The choice of method is therefore dependent on the questions that need answering. Comparing and compiling results from more than one method may provide more robust results than using only one approach. The available data are, however, limited and sometimes not sufficient to make quantitative estimates of the contribution of meat to human salmonellosis across EU. Even where data are available they are rarely fully used to identify the main sources of human salmonellosis in a source attribution model. In the EU, among the foodborne cases of human salmonellosis, eggs and egg products are still the most frequently implicated sources. Meat is also an important source of foodborne salmonellosis, with poultry and pork implicated more often than beef and lamb. More specific conclusions about the relative importance of specific meat categories brought into the kitchen raw, for example, fresh meat and products thereof, minced meat and meat preparations, cannot be made at present. According to outbreak data in the EU, eggs and egg products are the foods most commonly implicated in human salmonellosis. Meat especially poultry and pork meats are also commonly involved. Outbreak data collated at the EU level and in many MS do not allow clear identification of meat categories (such as carcasses, fresh meat and products thereof, minced meat and meat preparations) involved in human salmonellosis because food have not been uniformly categorised. In addition, as information is rarely available on food handling and processing practices, it is often not possible to trace back Salmonella contamination to the original source (food type) or to deduce the impact of consumer handling. Case control studies of sporadic cases of salmonellosis have identified the same foods as for outbreaks, as well as several non-food related factors. Source attribution through microbial subtyping in several MS (Denmark, Netherlands, Germany) has identified layers (eggs) as the major source of human salmonellosis. Among the meat producing animals, pigs and broilers are more important reservoirs for human salmonellosis than cattle. Such studies have not been published in other MS. There are differences in serotype distribution in human cases in MS which may be a consequence of differences in serotype distribution and prevalence of Salmonella in food animals, differences in animal production, food processing, food preparation and hygiene and different food consumption patterns. Comparative risk assessment is the only method that in principle allows the high resolution required to estimate the proportion of cases attributable to different meat categories as specified in the mandate. Nevertheless, this approach has not yet been used for human salmonellosis. Where few or contradictory data are available, formal structured expert opinions can be an alternative option for estimating source attribution. The few formal structured expert opinions on Salmonella source attribution published identify eggs and poultry as the most important food sources. Other foods including red meats were also identified. In the opinion data requirements for efficient source attribution of human salmonellosis by the different methods, are given.
