Eating 5-day-old pasta or rice can actually kill you

If meat is left out on the counter for too long, we all know we need to throw it out. But what about rice or pasta?

Although that carby goodness might seem harmless after sitting on the bench for a bit, you'll probably think twice about it once you hear about the bacterium Bacillus cereus.

It's not a particularly rare germ. B. cereus will happily live wherever it can – soil, food, or in the gut.

"The known natural habitats of B. cereus are wide-ranging, including soil, animals, insects, dust and plants," Anukriti Mathur, a biotechnology researcher at the Australian National University, explained to Science Alert.

"The bacteria will reproduce by utilising the nutrients from the food products [..] including rice, dairy products, spices, dried foods and vegetables."

Some strains of this bacterium are helpful for probiotics, but others can give you a nasty bout of food poisoning if given the ability to grow and proliferate - such as when you store food in the wrong conditions.

The worst scenarios can even bring death.

In 2005, one such case was recorded in the Journal of Clinical Microbiology - five children in one family got sick from eating four-day-old pasta salad.

According to the case study, pasta salad was prepared on a Friday, taken to a picnic on Saturday. After coming back from the picnic it was stored in the fridge until Monday evening, when the kids were fed it for dinner.  

That night the children began vomiting, and were taken to hospital. Tragically, the youngest child died; another suffered from liver failure but survived, and the others had less severe food poisoning and could be treated with fluids.

"B. cereus is a well-known cause of food-borne illness, but infection with this organism is not commonly reported because of its usually mild symptoms," the researchers explain.

"A fatal case due to liver failure after the consumption of pasta salad is described and demonstrates the possible severity."

While these deaths are mercifully rare, they have been recorded in the literature more than once. This week the news highlighted another old case published in 2011, about a 20-year-old student in Belgium who would prep his meals for the week – on that fateful occasion, it was spaghetti with tomato sauce.

He'd cooked the pasta five days earlier and would heat it up together with sauce. That day, he accidentally left his food on the kitchen bench for an unspecified amount of time. After diarrhoea, abdominal pain, and profuse vomiting, he died later that night.  

That night the children began vomiting, and were taken to hospital. Tragically, the youngest child died; another suffered from liver failure but survived, and the others had less severe food poisoning and could be treated with fluids.

"B. cereus is a well-known cause of food-borne illness, but infection with this organism is not commonly reported because of its usually mild symptoms," the researchers explain.

"A fatal case due to liver failure after the consumption of pasta salad is described and demonstrates the possible severity."

While these deaths are mercifully rare, they have been recorded in the literature more than once. This week the news highlighted another old case published in 2011, about a 20-year-old student in Belgium who would prep his meals for the week – on that fateful occasion, it was spaghetti with tomato sauce.

He'd cooked the pasta five days earlier and would heat it up together with sauce. That day, he accidentally left his food on the kitchen bench for an unspecified amount of time. After diarrhoea, abdominal pain, and profuse vomiting, he died later that night.  

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