Most of us have experienced food-borne illness at some point in our lives.
What we may not realize is that it is a serious public health concern.
The Government of Canada estimates that food-borne illness affects a total of four million Canadians annually, of which approximately 11,000 are hospitalized and over 200 die.
University of Saskatchewan (U of S) School of Public Health (SPH) student Patrick Seitzinger’s research is exploring innovative ways to support investigation into outbreaks of food-borne illness, and he is winning awards for it.
A student in the Master of Public Health (MPH) thesis option, Seitzinger’s study on the effects of recall bias on food-borne outbreak investigations claimed first prize in his program at the SPH Poster Day in October, and the Saskatchewan Epidemiology Association (SEA) student research award at the organization’s fall symposium in early November.
Funded by the Saskatchewan Health Research Foundation and the iTraP NSERC CREATE grant, Seitzinger’s study shows how recall bias, which reflects the limited ability of the human memory to remember exact information as time passes, has a significant impact on the accuracy of food consumption data collected to establish sources of infection in food-borne outbreak investigations.
“Depending on the scale of the outbreak, it can take anywhere from several days to several weeks after the onset of illness to collect a patient’s food history through questionnaires,” Seitzinger explained. “This can make it difficult for people to remember exactly what they ate, but epidemiologists rely on this information to identify the contaminated food sources making people sick.”
The study was possible thanks to an android smartphone app called Ethica iEpi, developed by U of S professors Nathaniel Osgood and Kevin Stanley. Seitzinger used the app, which acquires, stores and analyzes data on human behaviour, to track the food consumption of 96 university students who created comprehensive daily food diaries from photos, written descriptions, audio recordings and micro-surveys to produce a record of what they were eating.
Seitzinger measured the data collected from the instant food diaries against questionnaires completed seven and 18 days after the food was consumed. The questionnaires were modeled on those used by Canadian public health officials to collect food consumption histories.
The results showed that even after a week, the accuracy of the food history data was significantly lowered by people’s limited ability to remember exactly what they had eaten. The scale of the recall bias varied by food type - for example, it was more difficult for people to remember eating foods which are typically served as a garnish, such as sprouts, rather than as part of a meal.
From a public health perspective, recall bias presents a distinct barrier to the timely and accurate identification of contaminated food sources, which is critical to preventing cases of food-borne illness from spreading.
For this reason, Seitzinger’s study serves as an important first step to identifying and quantifying the threat of recall bias in food-borne outbreak investigations, so it can be accounted for in future studies.
One of the first students admitted to the MPH thesis option, which was introduced to the SPH earlier in the year, Seitzinger is working under the supervision of U of S professor and award-winning researcher Cheryl Waldner, which he describes as a great match.
It was an interest in Waldner’s research and the uniqueness of the MPH thesis option that drew him to the U of S.
He describes the program, which offers students the opportunity to study for an accredited MPH degree while simultaneously pursuing research interests, as ‘the best of both worlds’. “It’s like getting an MPH and an MSc at the same time,” he said.
It has also opened up a number of exciting research and development opportunities for Seitzinger, including a practicum with the Outbreak Management Division of the Public Health Agency of Canada, and an upcoming internship with the World Health Organization (WHO) in Geneva, Switzerland.
“So far, I’ve had the chance to do award-winning research, gain practical experience in my field and combine it all with studying for a professional MPH degree,” he said. “It’s been busy, but extremely rewarding.”