At Petting Zoos, Simple Disease Prevention Guidelines Frequently Ignored

A new study shows that simple guidelines to protect petting zoo patrons from disease-causing germs found in the zoo are frequently not followed, thus allowing the risks of contracting serious intestinal illnesses to persist. The study will be published in the July 1, 2007 issue of Clinical Infectious Diseases (and currently available online).

As we enter summertime, petting zoos open to families, allowing adults and children to learn about and experience animals. Unfortunately, in addition to goats, sheep, and other animals, petting zoos sometimes allow people to meet critters with names like E. coli, Salmonella, Cryptosporidium, and Campylobacterbacteria that live in the intestinal tracts of some animals and which are shed in the animal's feces.  Too often, these organisms make their way into the digestive tracts of the human visitors and cause serious illness.

According to a recent review, between 1991 and 2005 there were at least 55 outbreaks of intestinal disease associated with animals in public settings in the United States. The Centers for Disease Control and Prevention (CDC), among others, have offered simple guidelines that would help prevent the transmission of these diseases.

Petting zoos are frequently found at agricultural fairs, animal parks, and other public events. "While petting zoos are common and can be an excellent educational and social event, there are potential health risks that are not always being properly addressed," said J. Scott Weese, DVM, DVSc, dipACVIM, lead author of the study. Because the route of disease transmission is usually from animal feces to a human's mouth, guidelines to reduce the risk of disease are designed to interrupt this route. They include recommendations to wash hands after touching animals, to keep food and drinks outside of animal areas, and to prevent children from putting their hands or objects (such as pacifiers or sippy-cups) in their mouths while interacting with the animals.

The authors, from the University of Guelph in Ontario, Canada, sent a trained observer to 36 petting zoos in Ontario between May 25 and October 15, 2006. The observer gathered information about the layout of the petting zoo, the types of animals present and the types of animal contact permitted, manure removal, hand hygiene facilities, and whether food for human consumption was for sale in the petting zoo area.

Nearly all (94 percent) of the petting zoos provided hand hygiene facilities, but hand washing compliance ranged from zero to 77 percent. "On average, only 30 percent of people washed or disinfected their hands after leaving a petting zoo," said Dr. Weese. "This is concerning because hands are the most likely route of transmission of infectious agents from petting zoos."

Food or beverages were observed in the petting zoo at 82 percent of the events. Items that would come into contact with the mouths of infants and children were carried into the petting zoo at more than half the events. Weese observed: "It was a common occurrence to see people with items such as baby bottles, pacifiers, and baby toys in the petting zoo, which is of concern because these items would be put in the mouths of babies, who are at higher risk for acquiring certain zoonotic disease."

"Simple measures can be undertaken to reduce the risk of zoonotic disease transmission," said Weese. Measures such as placing the hand hygiene stations at the exit of a petting zoo, posting signs promoting hand hygiene, and making running water available were found to be associated with increased hand hygiene. Educating people about the risks associated with petting zoos may reduce the frequency with which food, beverages, or items that may end up in a child's mouth are brought into the zoo. Zoo operators can remove animals which are about to or have just given birth because such animals are more likely to shed pathogens.

Source: Infectious Diseases Society of America (IDSA)