In December 2002, Pennsylvania passed a bill requiring petting zoos and other animal exhibitions to provide hand-washing facilities and to post information about the more than 75 diseases humans can contract from contact with animals. The impetus for the bill was a an outbreak of E. coli in 2000 among visitors, most of them children, to a Montgomery County petting zoo. The Centers for Disease Control (CDC) reported that 55 cases of E. coli were confirmed, and 16 people were hospitalized. One child, a four-year-old girl, required a kidney transplant from her father.

According to the CDC, each year an estimated 73,000 people become ill and 61 people die from the potentially life-threatening bacteria, E. coli O157:H7. Although many cases are due to contaminated food and water, transmission of E. coli from animals to people is a growing concern. Several recent outbreaks at petting zoos across the country have prompted the CDC to issue federal safety guidelines to animal attractions that allow human-animal contact.

What is E. coli?

There are hundreds of E. coli (Escherichia coli) strains. Most of these bacteria are harmless and occur naturally in the intestines of healthy people and animals. Actually, some forms of E. coli bacteria are essential to our health. Others, such as E. coli O157:H7, are potentially deadly forms of bacteria that may cause severe illness, permanent kidney damage, brain damage, and even death in humans.

How Is E. coli transmitted to people?

E. coli O157:H7 is carried by many animals, including farm animals such as cattle and goats. The animals do not become ill or appear ill from the bacteria. There is no way to tell if an animal is carrying E. coli O157:H7 bacteria other than by performing a laboratory test. People who come into contact with the feces of an infected animal and who do not take proper hygienic measures—such as hand washing with anti-bacterial soap and not eating around the animals— can become infected with E. coli bacteria. Contact can occur from touching animals or any surface that may be contaminated with the feces of the animal which, in outdoor areas, could be nearly any surface. Pregnant women, elderly persons, and immuno-compromised individuals should avoid contact with animals due to their heightened risk of infection.

Children are at the greatest risk for serious complications caused by E. coli infection because of their heightened susceptibility to infection. This problem is compounded by the fact that children are difficult to control during zoo and fair visits, and are the least likely to understand or follow hygiene rules around animals. Young children display constant hand-to-mouth activity, which leads to many cases of zoonotic disease. Consequently, some zoos and fairs discourage or prohibit children under five years of age from having any contact with the animals.

What are the symptoms?

E. coli infection in humans causes severe abdominal cramps and bloody diarrhea, which may appear several days after infection. A fever may or may not be present. In the least severe cases, symptoms may last five to ten days. Life threatening complications, including kidney failure, are possible—especially in young children and infirm adults. If symptoms occur in young children or persons with compromised immune systems, they should be tested for E. coli infection immediately.

How can E. coli infection be prevented?

The best way to prevent infection is to avoid any direct contact with farm animals and their enclosures. If you do have contact with these animals, hygienic measures should be taken to help prevent infection from E. coli bacteria. Animal exhibits that allow human-animal contact should provide visitors with information on the possibility of infections from the animals. Such operations should also provide patrons with hand-washing facilities that contain running water, soap, and disposable towels. Neither food nor eating should be permitted near the animals or their enclosures. Other Health Dangers at Animal Attractions

Animal attractions that allow human-animal contact present many opportunities for zoonotic diseases to spread. In August 1999, a young black bear exhibited at a Iowa petting zoo died of rabies. Because the petting zoo permitted individuals to pet and wrestle with the bear, and the bear had been seen licking and nipping humans, the CDC suggested that people who had recent contact with the bear contact their doctors to see if rabies vaccinations were necessary.

But direct contact with animals is not necessary to contract most zoonotic diseases; indirect contact with contaminated surfaces is sufficient. The following is a list of some of the zoonotic diseases that pose a threat to patrons of petting zoos and animal fairs.

Zoonotic Disease	What Kind of Disease Is It?	What Animals Carry the Disease?	How Is It Transmitted to Humans?	What Are the Symptoms?
Cryptosporidiosis	Parasitic	Calves, lambs, deer and goats.	Contact with animal feces or drinking water contaminated by feces.	Human: diarrhea, abdominal pain, flu-like symptoms that may last up to 6 weeks—especially severe in the very young or very old. Animal: no clinical symptoms
Psittacosis	Chlamydial	Wild birds, pigeons, turkeys, parakeets, parrots.	May be inhaled from infected birds, their secretions, and contaminated facilities.	Human: headache, fever, pneumonia. Animal: Birds may be asymptomatic carriers. Others may have a generally unhealthy appearance, runny stool, and eye-nose discharge.
Rabies	Viral	All mammals: raccoons, skunks, foxes, coyotes, bats, and unvaccinated dogs and cats.	Animal bites and contact with feces, body secretions, or infected tissue.	Human: fever, headache, agitation, seizure, excess salivation, or death. Animal: disorientation, agitation, or excess salivation.
Salmonellosis	Bacterial	Farm animals, horses, reptiles (snakes, turtles, lizards) and amphibians (frogs, salamanders).	Direct or indirect contact with animal secretions.	Human: vomiting, diarrhea, fever, and chills. May develop into meningitis, sepsis and result in death. Animal: no clinical symptoms.
Toxoplasmosis	Parasitic	Affects many animals, including sheep and cattle. Cats are the primary carriers.	Direct contact with feces of infected animal.	Human: fever, swollen lymph nodes, muscle stiffness, and swollen liver or spleen. Spontaneous abortion and stillbirths are possible in pregnant women. Animal: no clinical signs. Lab testing required.