First Blue Bell, Now Jeni's: How Can Listeria Bacteria Survive In Ice Cream?

Jeni’s Splendid Ice Creams announced a recall of all its products Thursday. (Photo: Michael Derr/Flickr)

Ice cream is ingrained in our minds as a sweet, innocent treat, but lately it has been anything but.

Jeni’s Splendid Ice Creams has just recalled all of its products and is closing its stores because of a possible listeria outbreak. This comes just days after Blue Bell Creameries issued a recall of its entire product line. The Centers for Disease Control found that the listeria outbreak that prompted the Blue Bell recall dates back to 2010.

Three people in Kansas have died in the last year, and 10 people in four states have become sick from the listeria bacteria believed to have been in Blue Bell products, the Centers for Disease Control and Prevention says. The government agency is advising people to avoid Blue Bell products altogether.

Both Jeni’s and Blue Bell have vowed to find the root of the cause. “We will not reopen the kitchen until we can ensure the safety of our customers,” said Jeni’s Splendid Ice Creams CEO John Lowe.

Watch more about the Jeni’s recall in the video below:

According to the CDC, listeria is a serious infection usually caused by eating food contaminated with the bacterium Listeria moncytogenes. The disease typically affects older adults, pregnant women, newborns, and adults with weakened immune systems, but can affect others as well.

Listeria outbreaks have cropped up in deli meats, hot dogs, and cantaloupe. But how did it get into a frozen food like ice cream? Wouldn’t the cold kill it off?

According to board-certified infectious disease specialist Amesh A. Adalja, MD, an assistant professor at the University of Pittsburgh Medical Center, listeria actually loves cooler temperatures. “All bacteria has certain temperatures where they grow the fastest and listeria can survive in refrigerated foods,” he explains to Yahoo Health. In fact, he says that when listeria is grown in labs, scientists will lower the temperature to help it proliferate.

Related: Blue Bell Creameries Issues All-Product Recall For Listeria Fear

While listeria can’t grow at freezing temperatures, it can multiply once you get away from freezing and into the melting stage, says Sandra Eskin, director of food safety with The Pew Charitable Trusts. So, if you’re eating a contaminated bowl of ice cream and it starts to melt (as ice cream tends to do) you’re in the danger zone.

Listeria may cause only gastrointestinal discomfort in some people, but the real danger lies when the bacteria travel to the brain. Once a person eats contaminated ice cream, it can disseminate from the gastrointestinal tract to the bloodstream, and then travel to the brain. “Although it represents about 1 percent of all food-borne illnesses, it has a substantial fatality rate,” says Adalja. “It’s a very aggressive infection in certain people.”

How did listeria get into the ice creams in the first place? Adalja says it will be tough to pinpoint the source, but notes that listeria is commonly found in herd animals like cows. Listeria is normally killed off in the pasteurization process, but there’s a chance that something is going wrong in these plants. “I would assume there’s some kind of cross-contamination in the processing procedure where unpasteurized milk is getting in there,” he says. While Adalja notes that listeria can be passed on through fecal matter if someone doesn’t wash his or her hands properly, he says it’s doubtful that this would have gone on for five years (as in the case of the Blue Bell recall).

Related: First Blue Bell Ice Cream, Now Sabra Hummus — Why All The Food Recalls Lately?

This new series of outbreaks is scary, but Eskin notes that the government is about to change the way it tests for listeria. The bacteria is typically detected now via a routine test conducted by the state in which a plant resides, but companies aren’t required to test on their own. “There’s a system out there, but it’s a little more porous than some would like,” Eskin says.

However, once the Food and Drug Administration finalizes its prevention-based requirements for both food producers and inspectors, there will be mandated testing for listeria in facilities that produce ready-to-eat foods like ice cream. This is expected to go into effect in August.

In the meantime, both Eskin and Adalja say people shouldn’t avoid ice cream. While Adalja says the risk of listeria is “under-appreciated” by the general public, he adds, “this seems to be an isolated problem, so I don’t think people need to take caution with eating ice cream that’s not part of the national recalls.”

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