Nikolaus Huber ¹ Marina Meester ^2* Elena Lucia Sassu ³ Elizabeth Waller ⁴ Gergana Krumova-Valcheva ⁵ Giuseppe Aprea ⁶ Daniela D’Angelantonio ⁶ Veit Zoche-Golob ⁷ Silvia Scattolini ⁶ Emily Marriott ⁴ Richard Piers Smith ⁴ Elke Burow ^7,8 Guido Correia Carreira ⁷

• ¹ Institute of Food Safety, Food Technology and Veterinary Public Health, Unit of Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Vienna, Vienna, Austria
• ² Faculty of Veterinary Medicine, Department of Population Health Sciences, Utrecht University, Utrecht, Netherlands
• ³ Division for Animal Health, Austrian Agency for Health and Food Safety (AGES), Vienna, Vienna, Austria
• ⁴ Department of Epidemiological Sciences, animal plant and health agency, Weybridge, United Kingdom
• ⁵ National Diagnostic and Research Veterinary Medical Institute, National Food Safety Centre, Sofia, Bulgaria
• ⁶ Experimental Zooprophylactic Institute of Abruzzo and Molise G. Caporale, Teramo, Abruzzo, Italy
• ⁷ Department of Biological Safety, Federal Institute for Risk Assessment (BfR), Berlin, Baden-Württemberg, Germany
• ⁸ Department of Rural Development and Agriculture, Ministry of Agriculture, Environment and Climate Protection of the State of brandenburg, Potsdam, Germany

Salmonella spp. and hepatitis E virus (HEV) are significant foodborne zoonotic pathogens, impacting the health of livestock, farmers, and the general public. This study aimed to identify biosecurity measures (BSMs) against these pathogens on swine farms in Europe, the United States, and Canada. Overall, 1529 articles from three scientific databases were screened manually and with the artificial intelligence tool ASReview. We identified 54 BSMs from 32 articles, primarily focused on Salmonella spp. control. Among the extracted BSMs, only five measures for Salmonella spp. control, namely "acidification of feed", "acidification of drinking water", "rodent control", "all-in and all-out production" and "disinfection" had sufficient observations to conduct a meta-analysis. Of these five, acidification and rodent control were found to be protective measures, i.e. their summary odds ratios in the corresponding meta-analyses were lower than 1, indicating lower odds of Salmonella spp. presence on farms which did implement these BSM compared to farms which did not (OR around 0.25). All-in and all-out production showed a non-significant protective effect (OR = 0.71) while disinfection showed a statistically non-significant lack of association between disinfection and presence of Salmonella spp. on the farm (OR = 1.03). For HEV, no meta-analysis could be performed. Two BSMs were significantly associated with a lower risk of HEV presence according to multiple papers, namely disinfecting vehicles (OR = 0.30) and quarantining pigs before introducing them on the farm (OR = 0.48). A risk of bias assessment for each included article revealed a high risk in most articles, mainly due to selection and performance bias. This emphasizes the lack of standardized, high-quality study designs and robust empirical evidence linking BSM implementation to pathogen reduction. The limited data available for meta-analysis, coupled with the high RoB in the literature, highlights the urgent need for stronger evidence on the effectiveness of BSMs in mitigating the transmission and spread of zoonotic pathogens such as Salmonella spp. and HEV on pig farms.