Listeria can take up to 70 days to make itself known and cause food poisoning symptoms such as fever, weakness, vomiting, confusion, and a stiff neck.

By Amanda Gardner
Updated September 20, 2016
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This week the recall of 10,000 cases of Eggo Nutri-Grain Whole Wheat Waffles is shining a spotlight on a serious and dangerous repeat offender in the world of food poisoning: Listeria.

What is Listeria? Well, it's a type of bacteria with the full name of Listeria monocytogenes. Every year in the United States alone, this germ sickens 1,600 people (causing an illness called listeriosis) and kills 260 more, often from just a handful of outbreaks. All of these cases are caused by eating contaminated food. By contrast, Salmonella bacteria, a more common cause of food poisoning, are responsible for a million illnesses in the U.S. each year, including 19,000 hospitalizations and 380 deaths.

"Listeriosis is not as common as Salmonella by any means [but] there's typically a graver outcome," says John Linville, DVM, a food safety expert and adjunct associate professor at the College of Public Health, University of Nebraska Medical Center. "Up to 25% of illnesses can result in death."

An infection is more dangerous in older adults, anybody who has a weakened immune system (say from HIV/AIDS, cancer, diabetes, or after an organ transplant) and, particularly, pregnant women, because the bacteria can trigger miscarriages. "The mother themselves may have only mild flu-like symptoms but [Listeria] can pass through the placenta and cause stillbirth and deformities in fetuses," Linville says.

The good news is that in this most recent recall, no Eggo Waffles were found to have caused any illnesses or deaths, and may never do so. Kellogg issued a statement that the action was undertaken because the products "have the potential to be contaminated." The recall, now affecting 25 states, was presumably taken in response to contamination found in Kellogg facilities. (Check this link for a list of states and the date codes affected by the waffle recall.)

Kellogg has had similar recalls in the past. In 2009, the company recalled Eggo Buttermilk Waffles after the U.S. Food and Drug Administration found Listeria in its Atlanta plant,according to CNN.

Part of the problem is that the bacteria are all around us, found in soil, water, and many food products, including meat products such as packaged deli meats and hot dogs, raw milk, and dairy products, as well as soft cheeses made from raw milk and raw sprouts.

But unlike other foodborne germs that tend to perish or grow very slowly when refrigerated, Listeria thrive in cold environments. In fact, you can get the bacteria from smoked seafood, even after refrigeration. Heat, on the other hand, kills it, as does pasteurization, which is a high heat-sterilization that is performed by the manufacturer prior to packaging.

Even though deli meats like hot dogs and bologna are cooked, Listeria can make it onto the food after the cooking process, but before packaging, says Linville.

Another ominous feature of Listeria is that it can take up to 70 days to make itself known with symptoms such as fever, weakness, vomiting, confusion and a stiff neck. The symptoms can last for weeks.

The good news? Antibiotics can cure the infection. And simple preventative measures can keep Listeria out of your life.

The U.S. Centers for Disease Control and Prevention recommends practicing basic food hygiene. That means rinsing all produce well before preparing or eating it and even if you're planning to peel it. Scrub melons and cucumbers and dry all produce with a clean cloth or paper towel. Keep uncooked meat separate from all other foods, including cooked foods and prepared foods and take care of any spills in the fridge right away.

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Listeria can be killed by cooking (and pasteurizing milk and dairy products) so choose products wisely and prepare them according to the instructions. (And if you are pregnant, check out the CDC's food safety tips for pregnant women.)

And until the all-clear is signaled, avoid Eggo Nutri-Grain Whole Wheat Waffles, especially those that come in boxes of 10. So far, the recall does not extend to any other Eggo products. The company is asking consumers to throw the boxes away and contact the company for a refund. You can call 1-800-962-1413, Monday through Friday, 9 a.m. – 6 p.m. ET or visit Kellogg's website.

"I would seriously recommend not to play with it," says Linville. "Don't tempt fate by any means."