As of press time on Friday afternoon, Humber College and Toronto Public Health had yet to declare any determination of the cause of an outbreak of illness that affected 77 students at North campus residence on Thursday evening, sending 30 of them to hospital.
Toronto microbiologist Jason Tetro is the author of The Germ Code and The Germ Files. While he did not visit Humber campus or have any connection with investigating the outbreak, he explained to Humber Et Cetera some of the usual manifestations of food-bourne illness and the distinction from symptoms of flu.
What happens in a widespread outbreak of food poisoning, such as what happened at The Ex a few years ago?
There’s a bacterium called Staphylococcus aureus. It’s a very common bacterium on the skin of quite a number of people. And it has the capability of producing toxins. And one of these toxins – actually quite a number of them but one in particular – causes people to have significant gastrointestinal pain and vomiting, but no diarrhea. The toxin is produced by the bacterium as its growing in a very happy spot, and that means that it has to be damp or moist, It has to be warm and there has to be quite a bit of food. So when you see what happened with the Cronut Burgers and the jams, the jams were left out at room temperature -which was pretty warm because it was summer – so the bacteria can really grow. And then eventually it was spread across all the different burgers and that’s how people ended up getting sick.
Earlier in the news cycle on the incident at Humber there was some speculation that it could have possibly been influenza and that everybody just happened to get the flu at the same time.
Okay, first of all influenza normally doesn’t cause vomiting so influenza is just completely out of the picture. That is a respiratory virus. The symptoms of the flu are coughs, fever and fatigue. Gastrointestinal pain and vomiting could not have been caused by the flu. So anyone who mentioned that did not know what they were talking about. Another potential virus called Norovirus has also been making the rounds of Toronto. The first symptom from that is severe diarrhea, and only certain people from that will end up vomiting. While Norovirus could be suspected, it’s probably not that particular virus just because of the lack of everyone having to rush to the bathroom.
Speaking about damp environments, could you describe how something like this can spread around a kitchen?
Unless you use proper hand hygiene – washing your hands with warm soap and water or using an alcohol-based hand sanitizer for 15 seconds – then anything that you touch will transfer microbes. (So) when you have a busy kitchen and people are constantly touching various surfaces and food items, it’s incredibly easy to transfer a pathogen like Staphylococcus aureus from one area to another. I use to test that in the labs so it’s frightening.
Would you say that, going forward, there is cause for concern if something like this has already happened once at Humber College?
This type of event is usually rare. So it is concerning, but more from a compliance to food hygiene standards. If the proper food safety activities are used, this should never really happen. (But) it’s winter time, and so the reliance on foods that are stored and not fresh means that there’s going to be a higher risk for this type of pathogen. As long as we understand that food safety has to be even more critical in this time of year, we hopefully will not see this happen again.