Spatio-temporal prevalence and distribution of Salmonella spp. serovars in animal-origin foods in China: A comprehensive outlook derived from nine years of national surveillance, 2014-2022.

Salmonella spp. is one of the leading causes of bacterial foodborne illnesses in China, with animal-origin foods serving as the key transmission vectors. In this study, we analyzed the spatiotemporal prevalence and serotype distribution of Salmonella spp. in major animal-origin foods across China from 2014 to 2022. A total of 95,771 samples were randomly collected from retail markets across 26 provinces in China, from where 8859 Salmonella spp. isolates were serotyped. The overall prevalence of Salmonella in animal-origin foods was 9.25 %. The five most prevalent Salmonella serovars were S. enteritidis (14.23 %), S. typhimurium (8.52 %), S. Derby (6.30 %), S. Kentucky (5.95 %), and S. Rissen (5.24 %). During the 9-year surveillance period, the contamination rates in poultry meat and pork displayed an upward trend, with average detection rates of 17.16 % in poultry meat and 20.81 % in pork. Quantitative analysis revealed that raw meat had the highest Salmonella-contamination levels, followed by aquatic products, with prepared meat exhibiting the lowest levels. Regional variations in serotype distribution were evident. The prevalence of S. enteritidis revealed an ‌evident‌ decreasing trend from North (31.9 % [95 % CI: 29.1-34.6]) to South (6.7 % [95 % CI: 5.1-8.3]) (P < 0.05). S. typhimurium remained consistently distributed across regions (5.6-11.0 %). Notably, S. Kentucky increased significantly in raw chicken between 2015 (4.4 % [95 % CI: 2.3-6.4]) and 2022 (13.8 % [95 % CI: 12.2-15.4]) (P < 0.05), whereas S. Derby decreased in raw pork from 2015 (29.3 % [95 % CI: 25.5-33.1]) to 2021 (10.3 % [95 % CI: 8.9-11.8]) (P < 0.05). This nationwide study provides a comprehensive overview of Salmonella prevalence and serovar distribution in animal-origin foods in China. Our results highlight the need for targeted interventions such as enhanced surveillance programs, stricter biosecurity measures in poultry meat and pork production, and improved handling protocols in retail markets to mitigate Salmonella-contamination risks.