Dr. Stephen Freedman, a professor of pediatrics at the University of Calgary, speaks during an interview at the Alberta Children's Hospital in Calgary on Tuesday, Dec. 12, 2023. THE CANADIAN PRESS/Jeff McIntosh

CALGARY - Parents started showing up at Calgary hospitals with sick children on Sept. 1, the Friday before the Labour Day weekend.

The numbers grew on Saturday.

By Sunday, as more and more children fell ill, the first case of Shiga toxin-producing E. coli, or STEC, came back positive.

"It confirmed what our suspicion was," said Dr. Stephen Freedman, an emergency medicine physician at Alberta Children's Hospital who researches STEC infections at the University of Calgary's Cumming School of Medicine.

"It was not one or two a day, but 25-30 kids a day. By Sunday, 50 kids."

The E. coli outbreak, declared on Sept. 4, led to at least 448 infections — 39 children and one adult were hospitalized for severe illness. Another 32 secondary cases have also been linked.

It became the largest known outbreak in children under five, said Freedman.

Alberta Health Services said 23 children were diagnosed with hemolytic uremic syndrome, a complication affecting the blood and kidneys, and eight required dialysis.

The eight-week outbreak was traced back to Fueling Minds, a catering company and school lunch delivery service provider that prepared food for its Fueling Brains locations and other daycares in Calgary.

Health officials have said meat loaf and vegan loaf meals served for lunch Aug. 29 most likely contained the E. coli that led to the initial infections.

E. coli is a type of bacteria that can cause bloody diarrhea. Some strains cause more severe illness. Shiga toxin-producing E. coli is different as it produces a toxin that can cause complications.

Sarah MacDonald, whose four-year-old son attends one of the affected locations, said he came home from daycare Aug. 31 with what he thought was exciting news.

"He was really proud that he had pooped at daycare," she recalled. "He was like, 'I had poops and they were funny colours.' And I was like, 'Oh God, great. We're going to have the stomach flu now.'

"And when he got home, he kind of had a fever. So, we gave him Tylenol, put him to bed and hoped that he wouldn't get a (gastrointestinal) bug. But by 11 p.m., he started with diarrhea. He pooped his pants in his sleep. It was every 20-30 minutes for the next, I don't know, 60 hours."

MacDonald said she took her son to hospital because she was worried about dehydration. They returned the next day when his diarrhea continued.

He tested positive for a STEC infection and was admitted for three nights. He developed hemolytic uremic syndrome and was extremely sick but managed to recover at home, she said.

"He was traumatized by the whole experience."

Another parent, Katie McLean, was back and forth to Alberta Children's Hospital during the long weekend after her almost two-year-old daughter had blood in her stool.

"We got this swab done and they basically told us, 'You know, we're swabbing for a bunch of bacterial infections. The big scary one is E. coli,'" she recalled.

McLean thought it might be food poisoning but it was, in fact, E. coli.

When her family returned to the hospital Sunday, every chair in the emergency department was full and children were sleeping on the floor.

"It was just crazy."

That's where she overheard other parents talking about Fueling Brains, also her daughter's daycare. Some parents suggested there may have been something wrong with the food.

"When this dad told me that, I literally gasped and put my hand over my mouth. I said, 'That makes me so mad.' I teared up," she said. "It was like, 'How could this happen?'"

The company said at the time that it was deeply saddened that children were sick, and that it prioritizes health and safety. It said it was notified by Alberta Health Services of a potential outbreak Sept. 3 and immediately began working with the health authority to investigate the source.

Its central kitchen was shut down and reopened in mid-November to receive and serve food prepared by another provider.

The kitchen had been flagged during the outbreak for three critical health violations, including lack of proper sanitization methods, a pest infestation and food being transported without temperature control.

A government-appointed panel is investigating what went wrong and making recommendations on how to make commercially prepared food safer in Alberta daycares.

Freedman said there are many questions to be answered, including what regulations should be in place for kitchens serving children, and how people — from parents to health-care workers to the general public — could have been notified of the outbreak in a more timely manner.

At the city's hospitals, though, he said health-care workers responded well and managed to prevent deaths.

Freedman's research, which is on how to best manage E. coli infections, helped to provide clinical pathways, or a care map, for the children that included close monitoring and maintaining hydration.

"The question is how much hydration, and that's what we're studying," he said.

"Every study to date has shown worse results if the kids are dehydrated."

Research is taking place at four Canadian hospitals — Alberta Children's in Calgary, Stollery Children's in Edmonton, SickKids in Toronto and McMaster Children's in Hamilton — as well as 22 pediatric hospitals in the United States.

The study involves more than 1,000 children and, Freedman said, is being expanded to include some of those involved in the outbreak.

He said Calgary was well prepared to deal with the cases, because southern Alberta has one of the highest rates of Shiga toxin-producing E. coli in North America — including between 40 and 50 pediatric cases a year.

The higher rates, he said, are most likely related to the number of cattle in the province.

"Cattle harbour this bacteria. We have a lot of cattle in Alberta. Cattle typically graze and they poop where they graze, and often here they are at the Foothills. So poop runs downhill when it rains or when it snows," said Freedman.

"The bacteria that they are passing ... gets into our water supply or onto our produce, our vegetables and other elements."

Most cases, he said, are not part of an outbreak and some aren't related to undercooked beef.

"It's more random and it's acquired more locally, often getting into our water, into our irrigation supply, going onto produce, going into lakes and streams where kids play, swallow water," he said.

Freedman said cities with higher case numbers in the U.S. are also along the eastern foothills of the Rockies: Salt Lake City and Denver.

This report by The Canadian Press was first published Dec. 31, 2023.

News from © The Canadian Press, 2023