Farm Fairs and Petting Zoos: A Review of Animal Contact as a Source of Zoonotic Enteric Disease

Many public venues such as farms, fairs, and petting zoos encourage animal contact for both educational and entertainment purposes. However, healthy farm animals, including cattle, small ruminants, and poultry, can be reservoirs for enteric zoonotic pathogens, with human infections resulting in nausea, vomiting, diarrhea, and, in some cases, severe complications that can lead to death. As animals shed these organisms in their feces, contamination of themselves and their surroundings is unavoidable. The majority of North Americans reside in urban and suburban settings, and the general public often possess limited knowledge of agricultural practices and minimal contact with farm animals. Furthermore, there is a lack of understanding of zoonotic pathogens, particularly how these pathogens are spread and the human behaviors that may increase the risk of infection. Human risk behaviors include hand-to-mouth contact immediately after physical contact with animals and their environments, a practice that facilitates the ingestion of pathogens. It is often young children who become ill due to their under-developed immune systems and poorer hygienic practices compared with adults, such as more frequent hand-to-mouth behaviors, and infrequent or improper hand washing. These illnesses are often preventable, simply through adequate hygiene and hand washing. Our objective was to use a structured approach to review the main causal organisms responsible for human illnesses acquired in petting zoo and open farm environments, Shiga toxin-producing Escherichia coli, nontyphoidal Salmonella, Campylobacter, and Cryptosporidium. Notable outbreaks involving direct contact with farm animals and farm, fair, or petting zoo environments are discussed and recommendations for how public venues can increase safety and hand hygiene compliance among visitors are proposed. The most effective protective measures against enteric illnesses include education of the public, increasing overall awareness of the risks and the importance of hand hygiene, as well as access to hand-washing facilities.