Sixth external quality assessment scheme for Salmonella typing

This report presents the results of the sixth round of the Salmonella External Quality Assessment (EQA) scheme for typing of Salmonella enterica spp. enterica (further EQA-6). The EQA covers the methods Pulsed Field Gel Electrophoresis (PFGE) and Multiple Locus Variable number of tandem repeat Analysis (MLVA). A total of 29 laboratories signed up for the EQA-6 that took place in October 2014-March 2015, however three laboratories did not submit any results. Salmonellosis is the second most commonly reported zoonotic disease with an EU notification rate of 20.4 cases per 100 000 population, and Salmonella is a common cause of foodborne outbreaks. Since 2007, ECDC's Programme on Food- and Waterborne Diseases and Zoonoses (FWD) has been responsible for the EU-wide surveillance of salmonellosis, including the facilitation of the detection and investigation of foodborne outbreaks. Surveillance data, including some basic typing parameters for the isolated pathogen, are reported by the Member States to the European Surveillance System (TESSy). Besides this basic characterisation of the pathogens, there is a public health value of using more advanced and more discriminatory typing techniques for surveillance of foodborne infections. The objectives of this EQA-6 are to assess the quality of PFGE and MLVA, and the comparability of the collected test results between participating public health national reference laboratories in EU/EEA and EU candidate countries. Strains for the EQA were selected to cover strains of current public health relevance in Europe. Sets of ten strains were selected for each method, i.e. a mixture of Salmonella serovars for PFGE and Salmonella Typhimurium strains for MLVA.