Though the circumstance around Calgary’s mid-2023 E. coli outbreak was in no way a success, a new study says it could’ve been much worse.

A decade of local research, outlined in a recently published study, led to fewer children developing serious health issues during the September 2023 E. coli outbreak.

Of the 448 people infected during that outbreak, 21 were diagnosed with hemolytic uremic syndrome (HUS), a severe condition characterized by the destruction of red blood cells and low platelets. This is about half the expected total for an outbreak that size, the research suggested.

Dr. Stephen Freedman, MD, Professor, Department of Pediatrics at the University of Calgary’s Cumming School of Medicine, said that the first step in the care process came from early identification. 

“We really rapidly identified that there was something unusual going on, and identified this could be an outbreak of Shiga toxin-producing E. coli (STEC),” he told LWC.

“On the first day in the emergency department, we saw a large number of children who were having bloody diarrhea. While we see bloody diarrhea sometimes, we saw an excessive number of them, and they were all very young, and they actually all seemed to know each other and went to the same daycares.”

Because of the familiarity of patients, most of whom were from 11 daycares, public health was alerted to the potential outbreak. Within around 36 hours, stool samples were positive for STEC. 

“That led to us putting in place and implementing a care pathway that was informed by research that we’ve been doing here in Calgary, through Alberta Children’s Hospital and the University of Calgary,” he said.

Care included frequent monitoring of children, particularly while they’re at risk of developing complications and dehydration.

“We were paying very close attention to hydration status because we also know that in children who have dehydration and are infected by STEC they’re more likely to have adverse outcomes, such as needing dialysis, having other severe complications, and unfortunately, it’s also associated with death in children,” Freedman said.

“This care pathway was already in place, but we had to scale it up and be able to provide this care to a very, very large number of children in a very short period of time, and this led to an excessively impressive collaboration between Peter Lougheed, South Health Campus and the Alberta Children’s Hospital.”

When infected children were brought to the hospital, they were given blood work, monitored, and if they developed complications, they would be hospitalized. Children who were reasonably well, having few complications, but needing to be hospitalized, were moved to Peter Lougheed Hospital. 

The Alberta Children’s Hospital became home for patients that doctors were very concerned about and may have needed tertiary level care, according to Freedman. This path was very different from the typical care for STEC infections, where families are given a list of things to monitor for and told to come back to the emergency room if symptoms worsened.

“All of this was informed by research, and we kind of knew what to expect, because we’ve been studying it and we knew what needed to be done to minimize complications, and we were able to respond,” he said.

“The knowledge that we had and expertise in this disease allowed everyone to know what all of these children needed very quickly.”

Kirrily Hull, whose son Hank was three years old when he tested positive for STEC, was impressed by the efficiency of the process and personal care. 

“Hank’s blood was taken and analyzed daily. Each time, a doctor would go over the results with us. The care process was organized, and everyone knew what needed to be done.  We were very thankful for this,” she said in a UCalgary-issued release.

Freedman said that he hopes the study reinforces the need for proactive monitoring of children.

“If they have STEC infection, if they have presumed high-risk STEC infection or confirmed high-risk STEC infection, the watch and wait approach is not appropriate, and they do need proactive blood tests and monitoring, maintaining and attention to hydration status, because we do strongly believe that that can improve outcomes for children.”

Unique outbreak does not contribute to high infection numbers

The outbreak happening in Calgary may have been lucky. Freedman said colleges in other cities have told him the outcomes may have been much different without the University’s ongoing research.

He compared it to the early days of COVID-19.

“It’s hard for me to predict (what might’ve happened without the care plan), but if you can recall back to the early days of Covid, nobody knew what to do, nobody knew how to manage these infected individuals, nobody knew how severe it was going to be. It was kind of learning on the fly,” Freedman said.

“Because we’re doing this research, we knew exactly what to anticipate as well as how to optimally handle these children. We have seen over the years many children not as proactively managed, who present very late for care and have very severe and adverse outcomes.”

Though Alberta has high year-over-year cases of E.coli, it is not directly related to, or prevented like, 2023’s outbreak.

“There’s two different types of epidemiologic processes. One is cases we see every year that are just kind of random and then there are outbreak cases. This outbreak was because there was a single food source that was infected, that was by or had contained STEC, that was then served to a large number of children,” Freedman said.

“There’s also endemic disease, meaning every year, we tend to have a high rate per capita of STEC and primarily that’s because we have a lot of cattle.”

Though harmless to them, cattle harbour STEC. When they excrete it in their stool, rainwater distributes the bacteria, where it can come into contact with humans through irrigation, among other ways.