What is the risk from wild animals in food-borne pathogen contamination of plants?

Fresh fruits, nuts and vegetables are increasingly linked to food-borne illnesses, outbreaks and recalls. The trend represents a modern-day public health conundrum wherein consumers are encouraged to eat more fresh produce to help prevent chronic health problems such as obesity and heart disease, but at the same time consumption of contaminated produce can lead to potentially life-threatening acute food-borne disease. Identification of environmental sources responsible for the contamination of raw and minimally processed or fresh-cut plant commodities is necessary to develop prevention strategies. Produce-related outbreaks have been caused by faecal contamination of plants or surrounding watersheds following intrusion by wild or feral animals. A wild animal shedding a zoonotic food-borne pathogen could contaminate plants directly through faecal deposition or indirectly via faecal contamination of agriculture water or soil in contact with the plants. Owing to the low infectious dose of zoonotic enteric pathogens and the potential for attachment and possibly ingress into edible parts of plants, even a low level of contamination from faecal pathogens represents a significant public health concern. This review focuses on potential produce food safety risks from wild animals at the pre-harvest level, and downstream processes that may promote pathogen survival and amplification that could lead to human food-borne illnesses, outbreaks, and recalls. Microbe-plant interactions for the major zoonotic food-borne pathogens and higher risk plant commodities are reviewed. Finally, current guidelines and regulations to minimize risks related to wild animal activity in the production environment are summarized.