11.15.2012

The Petting Zoo Problem

Last month, a toddler died from an E. coli infection acquired at a county fair. Petting zoos have caused dozens of outbreaks in the last decade, all while experts struggle to make them safer.

Katie Maness was 13 years old when her parents took her and two friends to the 2004 North Carolina State Fair in Raleigh. It was a beautiful October day, as her mother Becky recalls years later, and the three girls were excited to visit the petting zoo on their own.

Inside the zoo exhibit, the trio saw the usual suspects: cows, pigs and a goat. All were in a pen where visitors could interact with the animals free of barriers. But soon the goats began to jump onto visitors, and eventually the small-statured Katie was knocked to her hands and knees on the muddy ground.

The exhibit didn't offer any hand washing stations, only hand sanitizer dispensers, so Katie did her best to clean off with what was available, but could only hope to wipe away the worst of the grime before heading off to explore the rest of the fair.

That was on a Friday. By Tuesday Katie was too sick for school. On Wednesday she had bloody diarrhea. That's when her parents rushed her to the hospital, where they eventually learned she was infected with E. coli O157:H7, the dangerous bacteria most commonly associated with undercooked hamburger.

Katie had spent six days in the hospital when doctors expected to discharge her on Nov. 2, Election Day. Then she went into kidney failure. She had developed a case of hemolytic uremic syndrome, a condition that can result from severe E. coli infections, predominantly in children.

She needed to be moved to a pediatric intensive care unit, but all of the beds were already full.

Katie was weak, scared, frustrated and physically dissipating before her parents' eyes.

"It was a horrible, gut-wrenching experience to have your child that sick when there's nothing you can do," her mother Becky said. "At one point I really thought Katie was going to die."

As it turned out, Katie was one of 108 confirmed patients suffering E. coli infections in the region.

Katie eventually recovered, and health officials soon pinpointed a common link between her infection and all the others: attendance at the North Carolina State Fair.

Months later, an epidemiological investigation would put the blame almost squarely on the animals in the petting zoo, some of which were likely carrying the bacteria, and infected visitors by shedding E. coli in their feces.

Any infected animal could have left traces of the bacteria on the ground inside its pen, on its coat or on any surface people grasp, such as fence rails.

But the outbreak that sickened Katie and the other fairgoers was far from a rare occurrence. Since 2000, petting zoos and organized farm visits around the U.S. have caused at least 32 publicized outbreaks of E. coli, Salmonella and Cryptosporidium – pathogens traditionally associated with contaminated food. Between 1996 and 2010, the U.S. Centers for Disease Control and Prevention received reports of approximately 150 animal-to-human disease outbreaks in public settings.

Last month, North Carolina saw another petting zoo outbreak, this time at the Cleveland County Fair. At least 106 people fell ill with E. coli O157:H7, including 2-year-old Gage Lefevers, a Gastonia boy who died as a direct result of his infection.

Other children spent weeks in the hospital, some in the intensive care unit with hemolytic uremic syndrome.

Jordan McNair, a 12-year-old Cherryville boy, was finally released from Levine Children's Hospital last week after 35 days in treatment.

The day after McNair's release, North Carolina state health investigators officially declared the fair's petting zoo exhibit to be the cause of the outbreak. Runoff from rains during the duration of the fair likely helped spread the bacteria to other areas of the fairgrounds.

"These are just needless deaths and illnesses," Becky Maness said. "We should be smart enough to figure out a way to see animals without this happening."

Experts Work to Make Fairs Safer

Of the 106 people sickened at this year's Cleveland County Fair, 65 were children, as were more than half of the victims at the 2004 state fair outbreak.

Not only are children's developing immune systems more susceptible to infection, but young fairgoers often behave in ways that heighten their risk of infection. Kids may bite their nails or suck their thumbs after touching contaminated fur or fence rails. They are also less likely to wash their hands without supervision.

In 2005, the North Carolina General Assembly passed G.S. 106-520.3A, better known as 'Aedin's Law,' named after 2-year-old Aedin Grey, who developed hemolytic uremic syndrome in the 2004 state fair outbreak, along with Katie and 13 other children.

Developed around a Duke University study on reducing animal-to-human disease transfer, Aedin's Law places a number of mandates on petting zoo exhibits operating in the state: mandatory soap-and-water hand washing stations, signage warning of the potential risk of animal contact and fences separating humans from animal pens are among some of the requirements. The law even bars visitors from bringing in food, drinks, baby bottles or pacifiers.

Publicized outbreaks according to state (highlight for details):

But despite the new regulations, North Carolina was hit not only by the Cleveland County outbreak this year, but another E. coli outbreak at the 2011 state fair that sickened 25.

The problem, veterinarians and microbiologists say, is that visitors still don't understand the inherent risk of handling animals without proper hygiene.

"The challenge is we have a relatively naïve population that have not been around farms," said Dr. Jeff Bender, professor of veterinary health and epidemiology at the University of Minnesota. "They have no exposure to some bugs. We now have some new bugs – the biggest driver in the past 10 years being E. coli – and we have kids without good hand hygiene coming into places where these bugs exist."

Bender has been working to help tackle the petting zoo problem for more than a decade. He was part of the National Association of State Public Health Veterinarians committee that drafted the original compendium of measures to prevent disease from animals in public settings in the late 1990s. That group's detailed recommendations, regularly published by the CDC, include many of the measures adopted by Aedin's Law and emphasize the importance of hygiene and general awareness of risk.

To Bender, inadequate hand washing remains the single greatest contributor to animal-to-human disease transfer. He and others have conducted numerous studies on hand washing practices at petting zoos, finding that hand washing rates among visitors consistently fall in the 25 to 35 percent range.

"Clearly, we're not doing a very good job," he said. "We've gone to fairs and done surveys to see how many are operating on our recommendations. It's not that good. We've made some progress, but a lot more progress could be made."

A petting zoo operating according to the compendium guidelines would look something like the following: Animals are kept in an enclosed space that includes a 'transition area' at the entrance. In this area, signs inform visitors of the potential risk of live animal contact and list objects not allowed inside, such as food, toys and strollers. Inside, animals would be kept separate from humans within fenced pens. The single exit would include hand washing stations clearly sized for both adults and children. Attendants would actively encourage visitors to wash hands and keep the stations stocked with soap and water.

This year's Cleveland County Fair petting zoo did have hand washing stations, as well as signs advising visitors to wash their hands, said fair manager Calvin Hastings stated in interviews with local media. When Food Safety News contacted Hastings for more information on the exhibit's design and safety precautions, he directed all questions to the fair's attorney. That attorney, Max Gardner, did not respond to multiple interview requests.

In an interview with local news station WRAL, Jordan McNair's mother, Beth, said that the fair's hand washing station only had 'a bit' of soap when the boy tried to wash his hands.

Having attendants monitor those stations' supplies and encourage visitors to wash hands is a crucial element to stopping the spread of disease, Bender says. Perhaps even more importantly, everyone involved with organizing and attending the fair need a baseline understanding of the risk.

"We still need more awareness among both the people bringing animals to fairs and the people who bring their children," said Dr. Michele Jay-Russell, Program Manager for the Western Center for Food Safety at the University of California Davis, in an interview with Food Safety News. "We need to really respect these pathogens and understand that they are dangerous."

Looking to Advanced Solutions

In 2006, researchers from the U.S. Department of Agriculture, Ohio State University and Louisiana State University published a study that compared the presence of E. coli between populations of cattle at feedlots, slaughterhouses and fairground petting zoos.

First, the researchers found E. coli O157:H7 in 31 of the 32 fairgrounds it inspected, whether specifically in the cattle population or in the petting zoo environment itself. Beyond that, they found that 13 percent of both the petting zoo and feedlot populations carried E. coli.

"When we think about petting zoos, we generally imagine the animals there are at least cleaner than your average feedlot steer – that they've been raised with more attention and care, right?" Bender said. "Yes, these animals might be getting better care at the fair, but they're still part of the herd."

Animals infected with pathogens such as E. coli are known to shed bacteria at higher rates under stressful conditions. During transportation or when confronted with waves of petting zoo visitors, carrier animals might have increased chances of spreading the bacteria to humans or fellow herd members.

Some experts believe that lab-testing fair animals for major pathogens could become a viable method of preventing future outbreaks.

"Why don't we take the approach we take with restaurants? If you're sick with Salmonella, you can't go to work at a restaurant," said Dr. Mansour Samadpour, president and CEO of IEH Laboratories, one of the industry's largest food safety labs. "Why not qualify the animals? If you know an animal is infected, you could immediately take action to screen them."

Samadpour said that swab-testing an animal for pathogens could take as little as a day, and some local health agencies might be willing to bear that burden for the chance at preventing an outbreak.

Bender, on the other hand, said that the veterinarians committee has wrestled with the idea of testing for years, but the general consensus appears doubtful of the method's effectiveness.

"These pathogens are intermittently shed. We may test an animal one day and get nothing, but then it's shedding the next," Bender said. "We don't have a good testing mechanism – especially if they're being trucked and moved and stressed."

Experts hit another hurdle when deciding what to test for, if anything. If fair managers saw a list of the most common pathogens, they would likely complain that it cost too much, Bender said.

But Samadpour argued that testing would still screen out animals that happened to be shedding pathogens on the day they were tested, and that's a move toward preventing outbreaks.

During his interview with Food Safety News, Samadpour said that his laboratory would offer pro-bono processing support to any research institute willing to operate a pilot pathogen-screening program of up to 20 petting zoos.

"It would be interesting to do some research on the utility of testing," Jay-Russell said before turning to the same food-service analogy used by Samadpour: "When a person gets sick as a food handler, they have to provide a number of negative tests in a row. I think it would be worth considering something like that for these animals — especially cattle, which can be super-shedders."

Others have floated E. coli vaccines for cattle as another possible route of prevention. Vaccines developed by U.S. and Canadian companies have been shown to reduce the amount of E. coli shed by infected cattle by more than 50 percent.

"The vaccines aren't perfect, but they can reduce shedding, which adds to what I'd call the hurdle approach," Jay-Russell said. "There's a potential there to reduce infection rates when coupled with hand-washing and good hygiene."

Samadpour, on the other hand, believes the vaccines are not effective enough to make a worthwhile difference. Bender reiterated that even with test-screenings and vaccines, pathogens would still inevitably infiltrate petting zoo environments.

"In my experience, we just need to assume that all these animals are shedding pathogens, and so we should focus on improving hygiene as much as possible," Bender said.

The Future of Petting Zoos

Following the death of Gage Lefevers during last month's Cleveland County Fair outbreak, fair manager Calving Hastings questioned whether next year's fair would include a petting zoo at all.

But petting zoos are a useful and meaningful way to educate people about animal agriculture, said Jim Tucker, president and CEO of the International Association of Fairs. In all the reactions to the recent outbreaks, there exists little support for eliminating petting zoos from the fair experience.

"[The International Association of Fairs] has worked aggressively in the past 10 years to find and refine solutions to the spread of zoonotic diseases where humans and farm animals interact," Tucker said in an emailed statement.

Tucker said those managing future fairs need to actively educate petting zoo visitors with effective signage, provide adequate hand-washing stations near points of animal contact, and encourage safe visitor flow through safe and effective exhibit design.

Bender, Samadpour and Jay-Russell each agreed that they preferred measures to improve petting zoo safety over the argument that they should be eliminated altogether.

"There's a lot of value in children and their parents experiencing agriculture and petting zoos. I sure hope we don't end up having to ban them," Jay-Russell added. "On the other hand, I do feel that if a fair just doesn't have the resources and ability to follow the [state veterinarian association's] compendium, they should really consider not having these animal interactions."

On October 17, just 10 days after the end of the Cleveland County Fair, the 2012 North Carolina State Fair kicked off again in Raleigh. It ran for another 10 days, complete with a petting zoo and rabbit barn, and ended without of any outbreaks.

And while she might have skipped the petting zoo, this year's fair did have one unexpected fan in attendance: Katie Maness, no longer the scared girl in intensive care, but now a healthy, 21-year-old interpersonal communication major at NC State.

© Food Safety News

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