In the space of five days this October, three health departments opened investigations into Shiga toxin-producing E. coli (STEC) infections tied to animals at fall attractions: five confirmed cases, four of them hospitalized, at Bengtson’s Pumpkin Farm in Homer Glen, Illinois; five confirmed cases at Brookshire Farmsin San Luis Obispo, California, which has closed; and a cluster of sick children Dallas County is investigating in connection with the petting zoo at the State Fair of Texas. None of this is new. What follows is a short history of how we got here, and the prevention measures that have been written down, revised and re-published for twenty years.

This happens every year, and the numbers are not small.

The Compendium of Measures to Prevent Disease Associated with Animals in Public Settings has been published by the National Association of State Public Health Veterinarians (NASPHV) since 2005. The 2023 revision is summarized in the December 2023 issue of JAVMA, and the full version counts 156 outbreaks involving animals in public settings in the ten years ending in 2020. Those outbreaks caused 6,388 illnesses, 1,233 hospitalizations and 10 deaths. The full version also notes that outbreaks are only part of it: in a Minnesota study of non-outbreak illnesses linked to animal agriculture, 28 percent of the STEC patients had visited a fair, petting zoo, agritourism farm or similar venue, and six developed HUS.

I started tracking these outbreaks on Fair-Safety.com years ago. The outbreak list there runs back to the early 1990s, but it stops in 2015 and still points readers to the 2017 Compendium. It is overdue for an update, and this post is the start of it. Here is a selection of the U.S. E. coli outbreaks, old and new:

Year	Venue	State	What happened
2001	Wyandot County Fair	Ohio	92 E. coli O157 cases tied to the fair.
2002	Lane County Fair	Oregon	82 ill; the largest E. coli O157:H7 outbreak in Oregon history.
2003	Fort Bend County Fair	Texas	25 visitors and animal exhibitors sickened.
2004	North Carolina State Fair petting zoo	N.C.	108 cases; 15 children developed HUS. The outbreak strain was found in shavings on a stroller and on visitors’ shoes.
2005	Florida State Fair, Central Florida Fair, Strawberry Festival	Florida	63 sick after goat contact at petting zoos run by one vendor; 7 developed HUS.
2005	Big Fresno Fair petting zoo	Calif.	At least six children; a two-year-old suffered HUS, kidney failure and strokes. The petting zoo relied on hand sanitizer.
2007	Day camp petting zoo	Florida	Seven children infected; a goat was implicated.
2011	North Carolina State Fair	N.C.	At least 27 sickened from eight counties.
2012	Cleveland County Fair	N.C.	106 people reported ill.
2012	Willow Grove pumpkin patch	Wash.	Four children sickened after a pumpkin patch and corn maze visit.
2013	Dehn’s Pumpkins	Minn.	Three children after contact with goats and cattle; one developed HUS.
2014	Traveling petting zoo, county fairs	Minn.	More than a dozen sickened by one traveling petting zoo that worked three county fairs and a festival.
2015	Oxford County Fair	Maine	Two toddlers with the same rare E. coli O111 strain; 20-month-old Colton Guay died of HUS.
2016	Goat dairy farm, kidding season	Conn.	50 confirmed cases, including secondary spread; three developed HUS. Goats and the farm environment were widely positive.
2019	San Diego County Fair	Calif.	11 confirmed and 2 probable cases; three hospitalized; a two-year-old boy died. Animal and environmental tests were all negative.
2019	Minnesota State Fair, Miracle of Birth Center	Minn.	At least 11 sick, ages 2 to 43; six hospitalized, one HUS. Some never touched an animal.
2022	Farming day camp	Tenn.	Campers sickened; farm isolates matched patients by sequencing, and the farm euthanized two STEC-positive goat kids.
2023	Appalachian Fairgrounds school field trips	Tenn.	64 cases; seven hospitalized; four with HUS. Five of the nine lab-confirmed cases were household members of children who went.
2025	Arizona State Fair petting zoo	Ariz.	18 sick, median age 10; 11 hospitalized; six with HUS. No soap-and-water handwashing near the exhibit.
2026	Bengtson’s Pumpkin Farm	Ill.	Five confirmed, four hospitalized; petting zoo closed; investigation open.
2026	Brookshire Farms	Calif.	Five confirmed; whole farm closed voluntarily; investigation open.
2026	State Fair of Texas petting zoo	Texas	A “cluster” of children under investigation; at least two hospitalized.

A selection, not a complete list. Sources are linked in each row: Fair-Safety.com outbreak summaries, CDC MMWR, state and county health departments, OutbreakDatabase.com and news reports. Counts are as last reported by the investigating agency.

The list could be much longer. Fair-Safety.com also documents outbreaks of Cryptosporidium, Campylobacterand Salmonella at farms, fairs and zoos here and abroad, and Food Poison Journal has a longer history of petting zoo and fair outbreaks.

What the outbreaks have in common.

Read twenty-five years of these investigations and the same facts keep showing up. The Compendium pulls them together, and they explain this October as well as they explain 2004.

Healthy-looking animals carry it. Cattle, goats and sheep are the usual sources. They carry STEC without getting sick and shed it intermittently, and young animals – the calves, kids and lambs that draw children – shed more than adults. Stress from transport, crowding and handling increases shedding.

You do not have to touch an animal. Fur, saliva, railings, bedding, sawdust, hay bales, manure on a fence, dust, a stroller wheel, a shoe: all have carried the bacteria in past outbreaks. STEC can survive in soil for months. Minnesota’s 2019 State Fair cases included people who never touched an animal, and Connecticut’s 2016 goat farm outbreak spread to people who had only been near someone who visited.

Testing the animals afterward rarely settles it. Because shedding comes and goes, the Compendium warns that a negative test does not mean the animal was not shedding earlier. In San Diego in 2019, every petting zoo animal, every pony and 32 environmental samples tested negative – after a child had died. The Compendium does not recommend routine screening for this reason. Prevention has to assume the animals are positive.

Temporary exhibits are the riskiest. The Compendium says temporary and seasonal exhibits are particularly vulnerable to design flaws, and so are working farms that were never designed for public events. The full version gives examples that read like this month’s news – animal displays added to festivals, farm stands, pick-your-own farms and Christmas tree lots – and lists the usual problems: inadequate barriers, surfaces that cannot be cleaned, insufficient plumbing, missing signs and too few handwashing stations. The traveling vendor that sets up for a weekend is exactly the operation least likely to have running water at the exit.

Hand sanitizer is not handwashing. In outbreak after outbreak, the Compendium says, handwashing has been protective: lathering with soap and water lowered the risk, while feeding animals without washing afterward and drying hands on clothing raised it. The full version adds that soap and water is still preferred over sanitizer, which does not work equally well on all pathogens or on dirty hands. The 2005 Fresno petting zoo had alcohol sanitizer. So, twenty years later, did the 2025 Arizona State Fair.

Food and animals do not mix. Contamination of food and drinks by people who have just touched animals has caused outbreaks, and the full Compendium adds that buying food at a farm visit and eating sticky foods like ice cream and cotton candy have been associated with STEC illness. Feeding animals and then eating without washing raises the risk. Some petting zoos still sell feed in ice cream cones, which the Compendium specifically says not to do.

Young children are the most at risk. Children under five put their hands in their mouths, sit on the ground and get close to the animals, and they are the most likely to develop HUS. The 2023 Compendium says preweaned calves, lambs, goat kids, reptiles and live poultry are not appropriate where groups at high risk are expected – and on a fall weekend at a pumpkin patch, or a school field-trip day at a fair, that is a lot of the crowd. Add that young animals shed STEC more than adults, and it is no surprise that so many of the rows in that table end with a toddler on dialysis. More on HUS is at about-hus.com.

How to prevent them – the Compendium’s playbook.

None of this is a secret. The Compendium is free, it has been around in some form since 2005, and the 2023 edition is posted by CDC and published by the AVMA. Washington’s Department of Health has turned it into a practical guide for fairs. The core recommendations for operators:

• Tell visitors the risk before they go in. The Compendium calls educating visitors “of utmost importance”: awareness of the risk was protective in the 2004 North Carolina State Fair outbreak. That means signs, staff at the entrance, and information sent home before school field trips.
• Divide the venue into three zones. Animal areas, transition areas at every entrance and exit, and non-animal areas where food is sold and eaten. No animals except service animals in non-animal areas.
• Put soap, running water and paper towels at every exit. Enough sinks for peak crowds, at a height children can reach, and as close to the exit as possible – not across the midway.
• Staff the exit. A staff member at the exit reminding visitors to wash is one of the interventions the Compendium cites as improving handwashing.
• Keep food, drinks, bottles, pacifiers, sippy cups and toys out of animal areas. Provide stroller parking at the entrance.
• Control feeding. Allow it only where contact is controlled, never sell feed in edible containers, and keep feed and water bins away from the public.
• Keep the youngest children away from the riskiest animals. Children under five should not have direct contact with preweaned calves and similar high-risk animals, and should be supervised at all times around the rest.
• Design for one-way traffic and avoid overcrowding. Use double barriers where contact is not intended, remove manure promptly and keep manure tools and piles out of public reach.
• Use a veterinarian and keep records. Exhibit only healthy animals, keep sick animals and herds with recent diarrhea out, and keep records of where animals came from and where they have been, so investigators can trace them.
• Do not sell raw milk or unpasteurized cider. The full Compendium says their sale or distribution should be prohibited.

For parents and visitors, the short version: wash with soap and water as soon as you leave the animal area and before eating, even if you think you did not touch anything; do not eat, drink or let children use pacifiers or bottles in animal areas; do not let small children sit or play on the ground there; wash after handling strollers and shoes that went into the pens; and if a child develops bloody diarrhea within ten days of a farm or fair visit, see a doctor and tell them about the visit. Antibiotics and anti-diarrheal drugs are generally not recommended for suspected STEC in children.

Recommendations are not requirements.

Here is the uncomfortable part. As the full Compendium acknowledges, no U.S. federal law addresses the risk of disease transmission where animals and the public mix, and only some states regulate things like handwashing stations. The Compendium tells agencies to work to ensure compliance and to build its recommendations into regulations, and the full version notes that studies keep finding the recommendations are not fully followed. After Arizona’s outbreak, a bill requiring handwashing, signage and supervision at petting zoos died in the legislature; the Arizona State Fair and the Maricopa County Fair dropped direct animal contact on their own. Voluntary decisions by a few fairs are not a standard.

Every state should turn the Compendium into a rule: soap and running water at every animal-area exit, staff at the exit, no food in animal areas, no feed in cones, records of animal sources, and a public notice requirement when a cluster is identified. Every health department that opens one of these investigations should publish the case count, ages, hospitalizations and HUS cases on a schedule, sequence every isolate, and put the final report online, so the next operator can learn from it. Twenty-five years of outbreaks is enough data.

Frequently asked questions

Can you get E. coli at a petting zoo without touching an animal? Yes. Outbreaks have been traced to railings, bedding, sawdust, hay bales, dust and contaminated shoes and strollers, and STEC can survive in soil for months.

Is hand sanitizer enough after a petting zoo? No. The full 2023 Compendium says soap and running water is preferred, because sanitizers do not work well on dirty hands or equally well against all pathogens.

Who is most at risk? Children under five, adults over 65, pregnant people and people with weakened immune systems. Young children are the most likely to develop hemolytic uremic syndrome.

Are petting zoos regulated? There is no federal law addressing disease risk at animal exhibits. Some states require handwashing stations; most rely on voluntary guidance like the Compendium.