Listeria is a serious disease—but the latest nationwide frozen veggie recall won't hurt you if you play it smart

By Rachel Jacoby Zoldan
May 05, 2016

If you feel like you've heard a lot about listeria in the past few years, you're not wrong: There have been several recalls, both local and nationwide, due to the disease. And on Tuesday evening, the CDC issued a statement regarding the multi-state outbreak of listeria linked to frozen vegetables. More than 350 products like green beans, broccoli, peas, and blueberries sold under 42 brands at grocers including Safeway, Costco, and Trader Joe's have now been recalled, so, yes, this is really serious. (Check out the FDA recall here.)

But if you're not really sure of listeria is-or what it can do-know you're not alone. We checked in with internist and gastroentronologist Nitin Kumar, M.D., to find out exactly what's going on, what you can do about the listeria outbreak and if you really need to toss that frozen spinach. (Eaten Something from a Food Recall? Here's What to Do.)

1. Listeria is a type of bacteria that affects us through contaminated food.

"The [specific bacterium associated with this recall] is Listeria monocytogenes," says Dr. Kumar. "Currently, the CDC estimates 1,600 infections per year in the US." Listeria lives at room temperature, so it's not affected by the freezing or unfreezing process, notes Kumar. What's more is that it's not going to show up ASAP-"it can take weeks to develop an infection after eating the contaminated food, and the symptoms depend on the patient." They're usually flu-like (fever, chills, nausea, etc.), says Kumar, and can last for just a few days or can be more serious, leading to other conditions, and can even cause death.

2. Those with weakened immune systems are more at risk.

"Listeria infection is primarily an issue in people with a weak immune system and most healthy adults will not have any issues [lest for] a brief flu-like illness," says Kumar. "The elderly, people with HIV or AIDS, pregnant women, and those on medicines that weaken the immune system-chemotherapy, steroids, etc.-are at a higher risk." Pregnant women must take extra caution: The infection can be transmitted to the fetus, and result in premature birth, miscarriage, or infection of the newborn. (Do You Have a Stomach Bug, or Was It That Food You Ate?)

3. The CDC introduced amazing technology to uncover this listeria epidemic.

Thanks to a bunch of brilliant scientists, it was figured out that by looking at a pathogen's specific sequenced genome, they were able to trace the most recent headlines and recalls all the way back to 2013. As Dr. Kumar says, "[The CDC] actually sequence the genes of the bacteria to get a 'DNA fingerprint' to find the sporadic, slow-motion outbreaks that play out over years, such as the current recall. It's a brilliant application of what used to be lab science."

4. Check your frozen foods, and go fresh when possible.

This should go without saying, but if you're concerned you've picked up a package of listeria-stricken veggies, check the UPC code on the FDA's site. It's an easy and fast way to figure out what you've got on your hands. "Fresh is always preferred to frozen," Dr. Kumar says. (Psst... Here's A Guide for When to Toss All the Food In Your Fridge.)

5. But cook all frozen vegetables carefully.

While Dr. Kumar and the CDC both admit the number of cases reported is limited, "thoroughly cook your frozen vegetables, and to put safe food habits in place that will protect you from other food pathogens," says Dr. Kumar. "Always wash raw vegetables before you eat them."