Scientists learn more about uncommon form of E. coli that can cause kidney failure in kids

Dr. Stephen Freedman, MD, is a paediatric emergency medicine physician who is leading a multidisciplinary group of researchers from across North America who are evaluating a treatment protocol for a type of Escherichia coli (E. coli) infection called Shiga-toxin producing E. coli (or STEC).

Alberta has one of the highest rates of STEC infections in the world and Calgary recently experienced the largest outbreak ever in children less than five years of age. STEC infections can lead to devastating outcomes including kidney failure and stroke. Investigators have worked to provide the best evidence-based care to infected children in a standardized manner while simultaneously evaluating novel treatment approaches. However, often to go forward, it is important to look back.

Freedman spoke to Kelly Johnston about a review he recently published in the New England Journal of Medicine and the ongoing study.

Why is a review important?

STEC is a relatively uncommon disease and as such most frontline health-care providers, such as family doctors and emergency physicians, are unfamiliar with the associated risks and emerging evidence. There hasn’t been a clinically focused article that summarizes the key points that clinicians should know in almost 20 years.

We really wanted to educate clinicians about this disease because having an understanding of the basic microbiology and the natural history of symptoms and complications can dramatically improve approaches to diagnosis, monitoring and management. These fundamental principles helped us provide standardized care to minimize the number of children with adverse outcomes during the latest outbreak.

Can you give me an example of one of the key points?

Within STEC there are high-risk and low-risk bacteria. Some are not too bad, while others have a high likelihood of causing adverse outcomes. The review allows us to provide guidance on how to differentiate between them based on the various diagnostic approaches used around the world.

We also focus on timelines because STEC infections are tricky, with kids often getting better before they get worse and then developing complications. Monitoring is very important; stopping too early or not monitoring often enough can lead to children deteriorating at home and having evolving complications go undetected. As such, we highlight approaches to reduce the likelihood of complications.

Is there another highlight you want to share?

The review highlights the importance of close collaborations with microbiologists to ensure they understand the information that clinicians need to guide care so they can optimize the algorithms used in laboratories and how that information should be conveyed in reports. The information gathered in the review helps clinicians interpret the tests and know when and how to act.

How does the review and your ongoing research on STEC impact care?

We have established clinical care pathways in Alberta. Anytime there is a child with this infection across the province, the ordering physician is contacted, and we help them understand what the microbiology result means, how to monitor the child and how to optimize care. The education focuses on determining when blood work and screening are needed, when hospitalization is required, and if specialized care is indicated.

What stage is the study at?

With funding from the National Institutes of Health (NIH) and Canadian Institutes of Health Research (CIHR), over 1,000 children will be enrolled at 26 sites. Two are in Alberta, with the other 24 sites spread across Canada and the United States. Over the past 12 months, we have enrolled over 350 children.

What the study focuses on is the volume of intravenous fluids being administered to determine what the right balance is between promoting blood flow to the body’s organs to preserve their functioning versus receiving too much fluid that has the potential to lead to complications from volume overload. With the recent outbreak in Calgary, we have received additional funding from the NIH to conduct long-term followup of children with STEC infections of all severities, from asymptomatic to severe, to inform our understanding of long-term complications.

People become infected with STEC when they eat any product contaminated with the bacteria. Young children are more susceptible to complications from infection. The bacteria lives in the intestines of healthy cattle, and meat can become contaminated during the slaughtering process. The bacteria is also passed in their feces and consequently can contaminate water sources.

Freedman’s studies are supported by the Canadian Institutes of Health Research, the National Institutes of Health Research in the U.S., the Alberta Children’s Hospital Research Institute and the Alberta Children’s Hospital Foundation.