Toronto Public Health officials said Wednesday 34 people have reported symptoms of food-borne illness after eating at the CNE. While an investigation into the source continues, a concession stand selling ‘cronut’ burgers has voluntarily shut down as a result.

Paramedics treated at least 12 CNE patrons for symptoms of gastrointestinal illness Tuesday. Five of them were taken to hospital for further treatment. None were admitted to hospital.

While the cause of their illness isn’t yet known, some are blaming the ‘cronut’ burger – a cheese-coated beef patty sandwiched in a ‘cronut’ -- the trendy doughnut-like confection made from croissant dough.

The CNE’s Epic Burgers & Waffles stand, which sold the burgers, has been voluntarily shut down and is being inspected by Toronto Public Health, according to the agency’s head of food safety.

Associate Medical Officer of Health Dr. Lisa Berger confirmed that Epic Burgers had voluntarily shut down late Tuesday as a precaution. She said the agency conducted a three-hour inspection of the premise on Wednesday.

Berger said the investigation is in its early stages and the agency has no confirmation on where or from what food source those affected became ill.

“We are conducting a thorough investigation which will include interviewing a number of cases,” she said.

Toronto Public Health has taken food samples from the concession stand for testing at the agency’s laboratory. Epic Burgers is expected to remain closed until the investigation is complete. The lab results are expected to be available in 48-72 hours.

Berger said TPH is looking to speak with people who consumed food at the CNE between Aug.16-20.

Chris Parnell told CTV Toronto earlier Wednesday he became ill hours after eating one of the burgers.

When he started feeling sick, he decided to leave the park but had to pull his car over numerous times on the way home.

“I was able to get on the 401 in which I had to pull over 5x before Mavis road exit,” Parnell wrote in an email to CTV Toronto.

Parnell eventually pulled his car over at a Tim Horton’s where he “blacked out.”

“I ended up being taken to a hospital in Brampton where they had confirmed I had food poison and was now dehydrated and very I'll (sic),” Parnell wrote.

Kirk Chen told CP24 he also became violently ill after eating one of the burgers.

“I just started vomiting…until five o’clock in the morning,” he said.

Most of the ill patrons shared common symptoms, according to Toronto EMS spokesperson Kim McKinnon.

“The typical things you have when you’re feeling really sick to your stomach," McKinnon told CTV Toronto, referring to the common symptoms of gastrointestinal illness that can include abdominal cramps, nausea, vomiting, diarrhea and fever.

An investigation is being carried out by the CNE in conjunction with Toronto Public Health.

CNE General Manager David Bednar said Wednesday the concession stand operator is a “reputable operator' who is co-operating fully in the investigation.

He said CNE organizers continue to be “very concerned” about all visitors to the park.

“We … will do whatever's necessary to prevent this in the future,” he said.

The park said in a statement the CNE “has stringent food safety regulations in place which are monitored daily.”

Berger also stressed that the CNE continues to be a safe place for people to visit and eat food.

Famous for its bizarre menu of often grease-laden treats, this year's CNE offerings include items such as deep-fried butter and Nutella sweet potato fries.

The CNE runs in Toronto until Sept. 2.

With files from CTV Toronto’s Zuraidah Alman