Researchers emphasize handwashing in schools to prevent spread of illness
Lois Abraham, The Canadian Press
TORONTO - A teacher demonstrating the importance of handwashing can go a long way toward keeping students healthy by instilling good habits, says the author of a study on preventing school-based gastrointestinal outbreaks.
Prof. Marilyn Lee, who teaches in Ryerson University's School of Occupational and Public Health, says that lack of handwashing and improper food handling are two of the major reasons for the spread of the uncomfortable symptoms associated with gastrointestinal upsets.
In the confined space of a classroom, gastrointestinal illnesses can spread quickly, Lee said in an interview Thursday from Guelph, Ont.
Lee is the lead author of A Review of Gastrointestinal Outbreaks in Schools: Effective Infection Control Interventions. The study, in the December 2010 issue of the Journal of School Health, deals with food preparation in schools from kindergarten through university/college.
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.
Lee and epidemiologist Judy Greig of the Public Health Agency of Canada searched reports published between 1998 and 2008 to identify the cause of a gastrointestinal outbreak, how the infection was transmitted, the number of children affected, mortality rates, and control and prevention measures.
Co-author Greig and Lee looked at an estimated 500 articles before narrowing them down to 121 outbreaks that met all the criteria. About one-third of the reports were from North America (40) mostly from the U.S., with three from Canada 39 from Europe, 39 from Asia and the remainder from South America and the Middle East.
Slightly more than half of the outbreaks 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), water-borne (12 per cent) and via animal contact (11 per cent).
Lee said one reason more outbreaks occurred in elementary schools in the United States is they have cafeterias as a result of a subsidized national school lunch program while in Canadian grade schools children bring their lunches or go home for lunch.
Food-borne illnesses are "grossly underreported" to public health authorities, said Lee, and the ones that are reported are just the tip of the iceberg.
"People get sick and attribute it to the stomach flu or their doctor doesn't suggest a fecal sample being taken.
"Often they don't realize it's a food-borne illness and they just tough it out. And even if a fecal kit is given and it goes to a lab, a pathogen may not be identified because the person may not be 'shedding' that day or is starting to feel better," she added.
In addition to frequent handwashing including on educational field trips to farms the researchers found several ways to reduce the risk of food-borne illness.
People really need to learn food safety rules cook food thoroughly, only leave it out for a maximum of two hours because bacteria can multiply and refrigerate it at 4 C or less.
"Another take-home message is that cafeteria staff should take food-safety training courses. The food industry is a very fast-moving industry. There's a lot of turnover. ... A lot of them might not come from a food background specifically. They may be trained on the job. How do they get the training? Sometimes health units can provide it, sometimes private companies can supply it."
She also pointed out that school "administrators should understand the importance of having functioning washrooms with adequate hand-washing facilities warm water, liquid soap, some way to dry the hands and a waste-paper basket."
And cleaning staff should monitor washrooms throughout the day to make sure they're clean.
The jury is still out on hand sanitizers. "There have been studies done in schools and it's not overwhelmingly convincing that hand sanitizers are a good substitute for handwashing," Lee said.
Lee also said that students should have a separate eating area from the play or work area. She cited one outbreak in Massachusetts where 46 students got salmonella as a result of eating their lunch in the same area where they were performing dissections in science experiments.
"It should be common sense, but it's not. You'd think in science they'd know about micro-organisms," she said. "You can't see micro-organisms. You don't know that they're there."
She 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.
"I'm from a health inspector background and one of the things we look for in any of these studies that we do is good communication between the facility and the public health department because if there is an outbreak the people that are going to help are the health unit inspectors" who are trained in disease control.