Contribution of the use of microbiologically contaminated water in slaughterhouses to food safety risks

• Water used for slaughtering activities can transfer enteric pathogens on to carcass. • Depending on a variety of factors, such pathogens can constitute food safety risks. • It is important to identify and characterise risks associated with water used for slaughtering activities. • It is also important to characterise relevant food safety risks. Food animals can become contaminated with enteric pathogens during slaughter, with potentially significant consequences for food and public health safety. This overview examines the scientific evidence implicating slaughterhouses as critical points for microbiological contamination of meat, with particular focus on the role of process water as a potential source and vehicle for foodborne pathogens. Despite the extensive use of water—e.g., for carcass washing, equipment cleaning, and general hygiene, there is a notable lack of empirical data on how waterborne pathogens may contribute to food safety risks. This gap highlights the need to better characterize the potential for process water to act as a reservoir and a vehicle for foodborne pathogens. To address this, this overview proposes a framework for tracing, characterizing, and quantifying the food safety risks associated with water used during slaughter. It emphasizes the importance of generating experimental data on the survival, persistence, and fate of water-origin pathogens on or within meat. The ability of a pathogen to persist throughout processing and storage significantly influences its impact as a foodborne hazard, as it increases the likelihood that it reaches consumers at infectious doses. Establishing genetic relatedness among isolates recovered from slaughterhouse water, contaminated meat, and clinical cases of foodborne illness can confirm water as a contamination source. However, in general, robust microbiological and food chain surveys are needed to establish clearer links between water-mediated contamination in slaughterhouses and subsequent human illness. Addressing these research gaps is critical for designing effective interventions and ensuring meat safety from slaughter through distribution.