But not so fast, say public health officials, who are calling again for increased safety and awareness following the death of a young child in Maine this fall. Twenty month-old Colton Guay died October 6 of Hemolytic Uremic Syndrome, a severe complication resulting from exposure to E.coli bacteria.

Colton’s father Jon Guay, a sheriff’s deputy in Androscoggin County, said he believes Colton contracted E.coli from visiting the petting zoo at the Oxford County Fair in September. “There is no doubt in my mind how and when my son contracted this disease,” he wrote in a lengthy and heartbreaking Facebook post.

Another boy, 17-month-old Myles Herschaft of Auburn, Maine, also developed HUS after visiting the same fair, but recovered and is doing well, according to his parents.

The Maine Center for Disease Control and Prevention confirms both toddlers were exposed to the same strain of E.coli, 0111, one of several types that carry dangerous Shiga toxins that can lead to HUS. But according to Maine CDC spokesman John Martins, tests have not yet definitively linked the boys’ disease to the fair. “The investigation is ongoing,” he says.

Martins says soil and other samples have been collected from the fairgrounds and were sent to the CDC in Atlanta for further analysis. So far, there’s been no talk of any legal action by the Guays or Herschafts, but that could change if tests find solid evidence of E.coli contamination.

If confirmed, the Maine outbreak would be the latest in a number of E.coli outbreaks at agricultural fairs and petting zoos in the United States. One of the more high-profile cases occurred in North Carolina in 2004, when more than 100 people were sickened by E.coli linked to the petting zoo at the North Carolina State Fair. The state legislature responded by enacting strict public safety rules for petting zoos in a law called “Aedin’s Law,” named after a two-year-old girl who got sick.

Among other things, Aedin’s Law requires operators to get a special permit to operate a petting zoo or animal display at a state-sanctioned agricultural fair. Operators also must post warning signs about touching the animals, and they have to set up hand washing stations within 10 feet of zoo exits.

But despite Aedin’s Law, North Carolina had yet another big E.coli scare in 2012. Two year-old Hunter “Gage” LeFevers died and more than 100 others were sickened in an outbreak at the Cleveland County Fair in Shelby, North Carolina. According to ABC News, the E.coli was attributed not to the animals themselves, but heavy rains that had carried the bacteria to seating or parking areas. One of the state’s largest newspapers, The Raleigh News & Observer, promptly called for an end to all petting zoos in an editorial, saying they had “caused too much pain and sorrow for too many youngsters and their families in this state.”

According to the CDC in Atlanta, the number of E.coli, salmonella, and other intestinal, or enteric, disease outbreaks associated with animals in public settings increased between 1991 and 2005. From 1996 through 2012, some 200 outbreaks involving human-animal contact in public settings were reported to the CDC.

“Yes, it is definitely a growing public health concern,” said Megin Nichols, a CDC veterinarian and enteric disease expert, referring to the number of outbreaks at animal exhibits. Nichols attributes the increase to the recent general growth in interest in farming and farm animals.

Pathogenic E.coli bacteria live in the fecal matter of goats, sheep, cows, and even poultry and can survive for months in the soil and around the pens where animals are kept. The E.coli is usually harmless to the animal itself, but if ingested, through hand-to-mouth contact, it can make humans very sick. Very young children, people with compromised immune systems, and the elderly are the most vulnerable to developing life-threatening complications such as HUS, which can lead to kidney failure.

The key to preventing infection is better hygiene around farm animals, whether you’re in a public setting or working on a farm.

Nichols says the key to preventing infection is better hygiene around farm animals, whether you’re in a public setting or working on a farm. The CDC recommends that petting zoo operators, farmers, and others who work with farm animals follow the recommendations of the 2013 Compendium of Measures to Prevent Disease Associated with Animals in Public Settings, drawn up by the National Association of State Public Health Veterinarians. The document lists a host of measures, including posting signs at the entrance of animal areas warning of the dangers of touching them; supervising children carefully when they’re in the animal pens and not allowing them to sit down in animal areas; disallowing eating or drinking near animals; and banning strollers, pacifiers, and similar items in the areas. Hand-washing should be encouraged strongly after any animal contact.

That last component, says Nichols, is key. “I truly believe hand-washing is one of the best deterrents against the spread of disease from animals to humans.” For those who live and work on farms, constant hand washing is also highly recommended, as is using clothing and boots that are specifically dedicated for working with farm animals.

Although the Maine investigation is in the very early stages, a 2008 survey by a Portland-based field epidemiologist, Lisa Bondeson, and filed with the National Institutes of Health concluded that Maine agricultural fairs at that time were not properly informing the public about the risks of petting zoos. CDC spokesman Martins said the survey was not based on current information, was likely an independent action, and he could not elaborate on the survey’s findings.

As Maine gets closer to finding out what happened at the Oxford County Fair, state fair officials and local farming and public-health experts are calling for a renewed campaign to educate the public about the importance of washing hands immediately after touching farm animals. Among other things, the Maine State Fair Association plans an all-day seminar on the subject early next year.

Still mourning the loss of his young son, Jon Guay is awaiting the birth of a daughter in January, but vows to take an active role in educating the public about the potential dangers children face at petting zoos.

“It makes no difference what future investigation or test results yield,” Guay wrote, “as I know that HUS is real, is deadly, and affects many lives across this country every year. I pray that the lessons learned in Colton’s story are not forgotten.”