Pol-Hofstad, IEMooijman, KA2024-11-262024-11-262024-11-262024-09-2610.21945/rivm-2023-0342https://rivm.openrepository.com/handle/10029/627831Since 1992, the National Reference Laboratories (NRLs) from the EU Member States have been obliged to take part in an annual quality control, which consists of conducting 'proficiency tests'. The objective of these proficiency tests is to detect Salmonella bacteria in samples taken from the living environment of animals, such as stables. In 2023, all NRLs from the EU Member States were able to detect Salmonella in chicken faeces samples. All participating laboratories were able to detect both low and high concentrations of Salmonella. One laboratory needed a second attempt. Another laboratory initially obtained a poor score due to an administrative error. Using raw data, this laboratory was able to demonstrate that two samples had been switched. As a result, it became possible to upgrade its score to moderate performance. This was the outcome of the proficiency test organised by the European Union Reference Laboratory in October 2023. In total, 37 NRLs took part in this proficiency test. They included the NRLs from the 27 EU Member States, nine NRLs from other European countries and one NRL from a non-European country. The laboratories used a mandatory, internationally recognised analytical method to detect Salmonella in chicken faeces samples. Each laboratory was sent a set of samples that had been artificially contaminated with two different concentrations of Salmonella Typhimurium, or had not been contaminated at all. The proficiency test was organised by the European Union Reference Laboratory (EURL) for Salmonella, which is located at RIVM. One of EURL-Salmonella's key tasks is to monitor the quality of the Salmonella NRLs in Europe.application/pdfenRIVM rapport 2023-0342Report2024-11-26