It was reported that the 20-year-old college student died from B. cereus after eating spaghetti with tomato sauce that was cooked and left out of the fridge for 5 days, then it was reheated and consumed. Most people are not aware that B. cereus is commonly found just about everywhere in the environment, and it will begin to cause gastrointestinal illness if food isn’t stored properly, but death is rare.
Most often starchy foods like pasta and rice are the sources, but Bacillus cereus can affect other foods like cooked vegetables and meat dishes. Certain bacteria can produce toxins, the longer food that should be stored in the fridge is kept from refrigeration at room temperature the more likely it is these toxins will grow.
Bacillus cereus has a one-up on other bacteria because it produces a spore cell that is very resistant to heating. This means that heating leftovers to a high temperature to kill off bacteria may not have the same effect on food contaminated with B. cereus. While these spores are typically dormant, given the right temperature and conditions, like cooked food left out of refrigeration for too long, promotes growth and activity, and from there, they begin to produce toxins that can make us unwell.
There are two types of this bacteria infection: one that is associated with diarrhea and one that is associated with vomiting. While illnesses tend to resolve within a few days, certain people are more vulnerable, such as those with underlying conditions and children, and they may need medical attention.
One of the problems with B. cereus infections is that the symptoms are similar to those of other gastrointestinal illnesses, most people do not seek medical attention for these problems, so there aren’t firm numbers for how often B. cereus occurs. We do know that this is not the most common cause of gastroenteritis, other causes such as Campylobacter, E. coli, and Salmonella are probably more common, as well as other viral causes of gastroenteritis such as norovirus.
You can protect yourself by minimizing the amount of time food is in the danger zone of allowing toxins to grow, this is anything above the temperature of your refrigerator and below 60°C, and this is the temperature to which you should reheat your food. Consume your leftovers hot when they need to be hot and cold when they need to be cold.
If you are going to be keeping leftovers to eat over the following few days after cooking it, refrigerate it right away. It also helps to break up large batches into smaller portions to help the cold penetrate through the mass of the food more quickly. Smaller batches also mean that you won’t need to take all of the food out of the fridge every time you want some, keeping the rest refrigerated.
I follow the 2-hour/4-hour rule, which means that if something has been out of the fridge for up to two hours it’s generally safe to put it back in the fridge, if it has been out for any longer I throw it away, and after it has been out of refrigeration for longer than 4 hours it has become a risk. I also never eat leftovers that have been in the fridge for more than 2-3 days maximum. Food safety 101: When in doubt just throw it out.
While we are on the topic of food safety, hygiene is equally important. Before preparing food, wash your hands and the surfaces that you will be using, including cutting boards. Make sure that you are also using clean utensils and surfaces as well as rewashing your hands so as to not cross-contaminate your food when preparing the raw food and cooking. Cross-contamination can happen so easily, and no one wants to experience the repercussions of that.
