In the confined space of a classroom, gastrointestinal illnesses can spread quickly, causing sufferers many painful and uncomfortable symptoms. But what is to blame for a school-based outbreak? In most cases, improper food handling is the culprit, says a Ryerson University public health expert.
Professor Marilyn Lee, Ryerson's School of Occupational and Public Health, is the lead author of A Review of Gastrointestinal Outbreaks in Schools: Effective Infection Control Interventions. The North American-based study deals with the critical issue of food preparation in many schools from kindergarten through university/college. The National School Lunch Program, for example, provided low-cost or free meals to more than 30 million students across the United States in 2008.
Typically, gastrointestinal illnesses are short-lived and their symptoms - cramps, fever, vomiting and diarrhea - don't require medical treatment. Some children, however, require hospitalization and even, in the case of E.coli contamination, can die from their condition.
Together with epidemiologist Judy Greig of the Public Health Agency of Canada, Lee searched documented reports published between 1998 and 2008 to identify a number of factors, including the cause of a gastrointestinal outbreak, how the infection was transmitted, the number of children affected, mortality rates, and control and prevention measures.
"The reports of documented cases are just the tip of the iceberg," Lee says. "There are easily thousands of other outbreaks that aren't reported to public-health authorities. So, to avoid future outbreaks, it's important that people take lessons from this study."
Among the 121 outbreaks cited from the reports gathered in the study, slightly more than half involved bacterial infections (51 per cent) or viral infections (40 per cent). The rest were caused by one or more parasites. In almost half of the cases, transmission was identified as being food-borne (45 per cent), followed by person-to-person (16 per cent), waterborne (12 per cent) and via animal contact (11 per cent).
The researchers found that the risk of food-borne illness was reduced when food handlers practiced effective hand-washing and received food-safety training and certification. In addition, student-training programs on hand hygiene and enhanced cleaning and disinfection of schools were effective strategies.
"Everyone has a role to play," Lee says. "Many classrooms contain sinks, so teachers can model proper hand washing for their students. School administrators must ensure that students always have access to warm water, soap and paper towels; custodians must frequently check the cleanliness of bathrooms."
Lee also says it is vital that educational officials notify public-health authorities at the start of an outbreak - a step that was not taken by many of the schools in the study.
"Public-health representatives are experts in disease control, and can take steps to stop an outbreak promptly."
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