Contribution of different food and animal sources to human Salmonella infections in the European Union.

The laying hen reservoir was estimated to be the most important source of Salmonella in the EU.

Salmonella spp. is one of the most common and widely distributed foodborne pathogens in the European Union. Surveillance programs and intervention strategies to control foodborne salmonellosis have been implemented in EU Member States, but a precise evaluation of the effect of such interventions is difficult, partly due to the lack of information of the public-health impact of specific sources on the incidence of foodborne infections. To identify and prioritize effective food safety interventions, it is essential to quantify the contribution of important food sources to the burden of human salmonellosis.
Two methods were applied to attribute human Salmonella infections to the responsible food animal sources in the EU, specifically a microbial subtyping approach and an analysis of data from outbreak investigations. Human Salmonella infections reported to the European Centre for Disease Prevention and Control (ECDC), Salmonella serovar data collected as part of the EU-wide Baseline Surveys (BS) conducted in the period from 2005-2008, and data reported by the EU Member States in 2005-2009 including foodborne disease outbreaks published in the Community Summary Reports (CSRs) were available for analysis
Results showed that the relative contribution of food-animal sources varied between regions and countries. The laying hen reservoir was estimated to be the most important source in the EU, contributing with 43.8% (95% Credibility Interval (CI) 43.2 – 44.4%) of cases attributed to this source, followed by pigs (26.9%, 95% CI 26.3-27.6%). Turkeys and broilers were estimated to be less important sources of Salmonella, contributing with 4.0% (95% CI 3.8-4.3%) and 3.4% (95% CI 3.1-3.7%), respectively. A total of 9.2% of all salmonellosis cases were reported as being travel-related, and 3.6% of cases were reported as being part of outbreaks with unknown source. Nine percent of cases could not be attributed to any source included in the model.
Despite data limitations and the resulting uncertainty in the results, the obtained source attribution estimates are considered useful for delineating risk management strategies. These represent the first indication of which animal-food sources are most important for human salmonellosis in several countries, and highlight regional differences in the contribution of different food-animal sources for disease and on the effect of surveillance and control programs in place in EU Member States.
Source: EFSA,http://www.efsa.europa.eu/en