Comparison of Serovar Reporting Frequency in the United States Department of Agriculture Food Safety and Inspection Service and the National Center for Biotechnology Information Pathogen  Detection Databases of Salmonella Strains Isolated from Livestock

Salmonella is a significant threat to human health, causing an estimated 1.35 million illnesses each year in the United States. There is increasing consensus that regulatory strategies and industry efforts that target serovars of public health concern are essential to reduce human salmonellosis, and it is important to understand the data available to assess serovar distribution among food sources. We analyzed isolate data from 2015 to 2020 for 21 serovars common in food animals in public data sets available through the Food Safety and Inspection Service (FSIS) and National Center for Biotechnology Information Pathogen Detection database (NCBI PD). Following defined criteria, we obtained metadata from 7,812 and 12,248 Salmonella isolates on the NCBI and FSIS websites, respectively. Our analyses found significant differences in serovar distribution between (i) FSIS data and NCBI data contributed by non-FSIS sources and between (ii) different isolation sources for a commodity. Specifically, we found isolation patterns of certain serovars (e.g., Salmonella Infantis) coincided with reported outbreaks, and more serovars were overrepresented in the NCBI PD data set. Although our results suggest biases in Salmonella serovar distribution sets, we found consistent trends across data sets that indicate the value of public data sets for informing future subtype-specific Salmonella regulations and control efforts.