Outbreaks of zoonotic enteric disease associated with animal exhibits.

T he importance of zoonotic enteric disease transmission at animal exhibit settings has become apparent in recent years, as outbreaks associated with animal exhibits are reported with increasing frequency. Until recently, awareness of direct animal-to-human transmission of enteric pathogens was limited; there had been a few individual case reports. 1-3 With recent large outbreaks associated with public animal exhibits, this public health issue has expanded beyond the population of farm families and persons living in close proximity to cattle operations. The reasons that animal exhibit-associated outbreaks of enteric disease have become more common may include the shift in the human population from rural to urban environments. Patterns of interactions between humans and farm animals have changed from frequent daily activities associated with farm life to less frequent events that are clustered in space and time, such as visits to petting zoo farms and state and county fair exhibits. Annually, more than 125 million people attend agricultural fairs in the United States, 4 and in a recent survey 5 of 9,000 US residents, 2% of all respondents reported visiting an exhibit involving animal contact in the last 5 to 7 days. Generalizing those data to the US population suggests that almost 6 million people attend animal exhibits regularly, which is a high risk of exposure. Despite the high risk of exposure to enteric pathogens associated with attendance at animal exhibits, most visits to petting zoos, open farms, zoo-logic gardens, and agricultural fairs provide a safe learning experience for the public. However, human enteric pathogens such as Escherichia coli O157:H7, Salmonella enterica, and Cryptosporidium parvum are ubiquitous and can be shed intermittently by apparently healthy animals. Therefore, it is very difficult to establish a clear-cut strategy for preventing human exposures. The advice of veterinarians is often the first sought by operators of open farms or animal exhibits when a zoonotic disease problem arises. A summary of enteric disease outbreaks associated with animal exhibits, excluding those in which food or water consumed by visitors was the vehicle of infection, is provided in this report. The epizootiology of E coli O157:H7, S enterica, and C parvum is briefly reviewed, and guidelines and recommendations for prevention of exposures are discussed. Types of Animal Exhibits Three general categories of animal exhibits are permanent animal exhibits, temporary animal exhibits, and reoccurring animal exhibits. Permanent animal exhibits include petting zoos, children' s farms, and animal contact areas of …