US officials are warning people for the second time not to eat cookie dough due to high amounts of E. coli bacteria contained in the unbaked food. After making more research on the matter, the experts reported this Wednesday that their last year findings were not mistaken at all. Once again, they found that the principal cause of the illness was the flour.

All seemed to be just fine this year. No other scientist warned about the illness caused by the bacteria, but it’s possible that a lot of people kept eating the rest of the cookie dough they didn’t use in their desserts.

However, the day before Thanksgiving, a study performed by the US Centers for Disease Control and Prevention and published in the New England Journal of Medicine warned about the bacteria in the raw food.

The first outbreak of E. coli bacteria infection was between December 2015 and September 2016, when 63 people became sick without any explanation on how they contracted the illness. However, although it was tough, the CDC reported the flour was the one to blame for the bacteria.

More than a quarter of those patients — aged 1 to 95 and living across the country – were hospitalized. One of them even experienced kidney failure. Fortunately, the 63 people could recover eventually.

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The US passed in 2016 through an E. coli bacteria outbreak due to the flour used to prepare the cookie dough. Image credit: Smoky Mountains

High heat when baking kills most pathogens during the process. Doctors have always recommended not to eat raw food because, without the heat, the bacteria can’t disappear.

When talking about some dessert doughs, there’s already a risk of infection because of eggs and some of the illnesses coming with them, such as salmonella. But now, people should be more careful, as flour is another ingredient that’s able to make them sick.

“We’re not trying to ruin people’s holidays but we want them to be aware of the risks,” said Samuel J. Crowe, lead researcher and an epidemiologist with the division of foodborne, waterborne and environmental diseases at the CDC. “The bacteria is not uniformly distributed in a two-and-a-half pound bag of flour. A small amount could get you really sick. I’ve had E. coli and salmonella and it’s pretty darn unpleasant.”

No one associated flour with E. coli bacteria

When CDC experts perform this kind of study, they tend to use survey data. However, no person ever complained about the flour before 2015. Not even one patient was on their files naming the ingredient – much less, of course, the relation between the bacteria and flour.

Flour is not tracked in all questionnaires. That made the team start searching every men, women and children who were affected by the dough and reported suffering from the illness. However, they could only find 10 individuals.

The experts interviewed the patients for several hours, they asked them detailed and specific questions about what, when, and how they ate the dough. According to Dr. Crowe, the researchers did everything to understand the relation between the patients and to discover the cause of the outbreak.

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Normally, experts advise not to eat dough because of the eggs. Now, the flour turns to be another reason not to do it. Image credit: The Coupon Project

For the common person, it’s commonly complicated to recall the food it ate a month ago. For some people, it’s even trickier to remember what their lunch was. At least, that’s what Dr. Crowe thought while gathering the people.

According to him, some of them didn’t remember any food they ate before feeling sick. Others had a few memories about the flour used – which, in fact, was quite helpful. But just two of them could recall the exact dough, and talk about the physical characteristics of the food and the brand of the ingredients.

At first – probably as many researchers would have expected – Dr. Crowe believed that the ingredient leading to the sickness was the egg. But then, he found that two of the patients reported having used the exact flour on their mixes.

After further analysis, the researchers saw that the flour contained a dormant strain of E. coli.

According to Crowe, this bacteria is commonly found in wet environments – like raw hamburger meat and leafy vegetables. But after this research, he saw that it can also hide in dry products, such as flour.

Nearly 250 products contain flour, as the experts wrote.

Three ways to avoid getting the illness

The researchers named three options to get the E. coli bacteria out of the flour.

The first way would be to change the way the US producers manufacture the ingredient. They could increase the heat before packing the product, but this would also mean a change in the texture – a feature that most buyers look for.

The second one, and probably the hardest for the manufacturers, they could radiate the flour. However, they’d need to use high levels of radiation just to end with one bacteria.

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Kids are among the patients that are most vulnerable of getting infected with the E. coli bacteria. Image credit: CBC News

The third, and probably the hardest but for some buyers, would be to wait until the cookies are baked.

Jenny Scott, a senior adviser for the FDA Center for Food Safety and Applied Nutrition, said that children are among the most vulnerable of getting infected with the bacteria.

“As an adult you have the information to determine whether to take that risk, but when you give a child a ball of raw dough, you’re putting your risk values on that child.”

As Scott says, the responsibility and decision to eat cookie dough or not will lie mostly on adults.

Source: The New England Journal of Medicine