A University of Calgary–led research team finds that only 7% of children infected with Shiga toxin–producing Escherichia coli (STEC) developed hemolytic uremic syndrome (HUS) during a 395-case outbreak at 11 daycare centers in Alberta, Canada, perhaps partly due to daily lab monitoring for kidney injury.
The researchers investigated the outbreak among children and adults related to contaminated food served at the centers in August 2023, publishing the findings yesterday in JAMA Network Open.
An estimated 15% to 20% of children infected with STEC develop HUS, more than half of whom require dialysis. “Alberta, Canada, has one of the highest STEC infection rates in North America,” the authors wrote. “Accordingly, the province has developed expertise in diagnostics, public health responses, and care pathways.”
Substantial use of health care resources
In total, 326 primary and 33 secondary infections occurred among 288 children and 71 adults. Of the 359 infections, 18.4% caused no symptoms. There were 508 and 395 emergency department and STEC clinic visits, respectively, among the 285 children with outcome data.
Only 7% of children infected with STEC developed HUS, which is lower than reported in most prior outbreaks and sporadic case series.
HUS was documented in 7.4% of children, while no adults developed the condition. Forty children were hospitalized, nine needed dialysis, and three required intensive care. Daily lab monitoring for thrombotic microangiopathy (TMA) identified all future HUS cases. TMA is a life-threatening syndrome characterized by small blood-vessel injury, blood clots, and end-organ damage.
The most common symptoms in both children and adults were diarrhea, abdominal pain, and bloody diarrhea. TMA testing had 100% sensitivity, 95.7% specificity, and 96.1% diagnostic accuracy for HUS.
The study identified significant use of health care resources, the researchers said. “Only 7% of children infected with STEC developed HUS, which is lower than reported in most prior outbreaks and sporadic case series,” they wrote. “These findings highlight the importance of a coordinated public health response integrated with clinical care and suggest that proactive screening for TMA has the potential to mitigate adverse outcomes.”