An outbreak of E. coli O157 – the particularly nasty strain of E. coli that can cause hemolytic uremia (a serious kidney disease) and death – has been identified in Colorado, and signs are pointing toward a livestock show as the source. So far, 20 people have been identified as infected, including 19 children. The exact source of the infection is not clear, and could be food, water or contact with animals. However, considering the high percentage of children, the petting zoo is a likely source.

As we’ve discussed previously, petting zoos can be fun and educational events (particularly for children) but are always associated with some degree of infectious disease risk. Petting zoos are often poorly equipped to handle these risks, as we reported in a paper in Clinical Infectious Diseases a little while ago. Petting zoos are a risk because animals that appear healthy can still carry infectious diseases. This is particularly true for E. coli O157, which can be carried by perfectly healthy cattle. Despite the possibility of exposure to E. coli and other potentially harmful microorganisms, the potential for disease can be greatly reduced with some very basic measures, like handwashing, not eating in the petting zoo, handwashing, keeping baby bottles and other items out of the petting zoo, handwashing, and having signs encouraging people to wash their hands. The people in charge of this event stated that they had a well organized petting zoo with handwashing stations available, and that may very well be true. Having access to handwashing facilities is a critical step, but it doesn’t do anything if people don’t use them. Unfortunately, poor compliance with handwashing is very common and is one of the weakest links in infection control at petting zoos.

• Always wash your hands after leaving a petting zoo.
• Don’t eat in a petting zoo area.
• Don’t take items into the petting zoo that will go into a child’s mouth, like bottles, cups and soothers.