Watch CBS News

Why so many listeria recalls lately? A doctor explains what to know and symptoms to look for.

Frozen waffles recalled over listeria concerns
What to know about the frozen waffle recall due to potential listeria contamination 03:28

From deli meat and salmon to frozen waffles and pancakes, listeria recalls seem to be making headlines more frequently — but why?

There are a few reasons we may be seeing an uptick in these contaminations, including a more complicated food supply chain, explains Dr. Céline Gounder, CBS News medical contributor and editor-at-large for public health at KFF Health News.

"Every step of food processing, there's the opportunity for contamination. That's number one. Consumers want ready-to-eat food, so of course, they're more processed as a result," she said on "CBS Mornings."

In addition, "We have better tests. So it used to be we might not have been aware or known what made you sick. Now we can actually test, detect and tell you what made you sick."

While these recalls are seemingly more common, they're not something to ignore. Listeria can lead to serious illness and can even be fatal.

"You can develop a quite severe disease, including meningitis, which is when it's in your spinal cord, or sepsis, where the listeria gets into your bloodstream and can cause damage to your organs," Gounder said. 

So if you have a product on a recall list, the best thing to do is throw it away. 

"This is not worth the risk. This could be deadly. So really just dispose of anything that is on that recall list," she said. 

Listeria symptoms

Listeria infections are caused by eating food contaminated with the bacteria called Listeria monocytogenes. Symptoms to look out for include headaches, fevers, changes in your mental status, difficulty walking and even seizures. 

The Centers for Disease Control and Prevention warns that people may also experience a stiff neck and flu-like symptoms, such as muscle aches and fatigue.

Some people are also at higher risk of severe cases, including those who are pregnant, newborns, adults 65 or older, and those with weakened immune systems. 

"Some of the foods that we consider high risk — and why we tell pregnant women, for example, not to eat them — are deli meats and soft cheeses," Gounder said. "Those foods are very high risk for contamination."

Can you cook listeria out of food?

Thoroughly cooking or reheating food can kill listeria, but Gounder notes, "You need to be cooking things at a high enough temperature."

The CDC recommends reheating deli meat, cold cuts, hot dogs and fermented or dry sausages to 165°F or until steaming hot. The same goes for pasteurized soft cheeses and deli-sliced cheeses — heat to an internal temperature of 165°F before eating.

"Freezing does not kill bacteria like listeria. It's a very hardy bacteria," Gounder said. Refrigeration also does not kill listeria.

How does listeria spread?

The most common way listeria spreads is through food, Gounder explains, but it can also spread through cross-contamination.

"It could be from other foods, it could be equipment or surfaces that were contaminated. We find listeria in the soil and water. So a lot of different ways it could get into a frozen waffle (for example)," she said.

If you had a recalled product in your fridge or freezer or elsewhere in your kitchen, it's important to disinfect those surfaces to prevent further contamination. 

How long does listeria take to make you sick?

How quickly symptoms occur depends on the type of illness.

Intestinal illness symptoms usually start within 24 hours after eating contaminated food and usually last one to three days, according to the CDC.

For invasive illness, meaning the bacteria has spread beyond the gut, symptoms usually start within two weeks after eating contaminated food.

How is listeria treated?

Treatment depends on the severity of the illness. It may include antibiotics or fluids to prevent dehydration. Seek medical attention if you suspect you're infected. 

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.