The use of dynamic prevalence maps to assess the prevalence of Salmonella in broiler flocks in the Valencian Community, Spain.

The aim of this study was to design and implement a dynamic prevalence map for managing the data collected within the framework of the Salmonella spp. National control plan in broiler flocks, using a data set from the Valencian Community, Spain. Such a map would be a useful tool for veterinarians seeking to define control options. The development of the mapping tool for this study involved three main phases: data collection, data analysis and data representation. The data used were obtained from the results of the National Control Programme (based on European Commission [EC] Regulation No. 2160/2003). The Salmonella prevalence data were represented on a map of the Valencian Community, which included geographical information on flock locations to facilitate the interpretation of the results from monitoring. The average prevalence of Salmonella spp. was 2.74% from 2009 to 2013. Moreover, the proportion of broiler flocks that remained positive for the target serovars according to EC Regulation No. 2160/2003 (S. Enteritidis and/orS. Typhimurium [including monophasic S. Typhimurium]) was less than 1%. Over the five-year period of the study (2009-2013), the area of Bajo Maestrazgo had the highest level of Salmonella spp. prevalence every year, thereby validating the usefulness of this mapping tool. The aim of the study is to detect geographical 'highpressure' Salmonella zones over time and make suggestions on where efforts should be focused in this region to reduce future Salmonella spp. prevalence. Local Veterinary Services could, using the map, identify the infection pressure of Salmonella in the geographical areas where farms are located. Proximity to higher prevalences may imply an increased risk of flock contamination. Although annual data are represented, data can be presented in real time with regular frequency (daily, weekly, monthly or quarterly) or even over periods of several years. Therefore, the dynamic prevalence map provides extremely useful epidemiological information to veterinarians on the prevention of Salmonella.