Hot dogs, sprouts, and store cut melon
Certain foods, such as hot dogs, raw sprouts, and store-cut melon, have been associated with listeria outbreaks.
First the good news: Widespread listeria outbreaks are uncommon. Especially when it comes to big multistate outbreaks — the kind that make the national news and are linked to a specific food product — there may be only a few in a given year.
The Centers for Disease Control and Prevention (CDC) is the government organization that keeps tabs on listeria-related infections, and its most recent nationwide data come from 2020. That year there were five multistate listeria outbreaks that resulted in 36 illnesses and four deaths.
But even though big outbreaks are rare, listeriosis (the medical term for a listeria infection) are still the third-leading cause of food poisoning death in the United States. Listeria sickens roughly 1,600 people annually — 260 of whom die as a result of the infection, says Jennifer Hunter, MPH, DrPH, an epidemiologist who has worked with the Centers for Disease Control and Prevention’s Epidemic Intelligence Service.
Also, the vast majority of listeria infections probably go unreported. That’s because bacteria of the genus Listeria tend to produce only mild GI symptoms — such as a stomachache or diarrhea — in healthy adults.
That’s not the case for pregnant women, seniors, or anyone with a weakened immune system. These at-risk groups may all experience life-threatening complications as a result of a listeria infection.
These key facts about how to reduce the risk of spreading or being infected with listeria can help you keep yourself and others safe.
Some Foods Are More Likely to Become Contaminated With Listeria Than Others
“It used to be that outbreaks of listeriosis were linked to the consumption of deli meats and hot dogs,” says Linda Harris, PhD, a professor of cooperative extension in microbial food safety at the University of California, Davis.
While these outbreaks were never common, some research has estimated that 20 percent of people infected by listeria picked up the bacteria from cold cuts, unheated hot dogs, or undercooked meat.
Listeria concerns caused the meat industry to change the way it processed and packaged its products in order to prevent contamination. These efforts have paid off. Multistate listeria outbreaks are now very rare, according to CDC records.
More recently, large-scale listeria outbreaks have tended to turn up in dairy products (including in ice cream and soft cheeses) and in produce (cantaloupe, sprouts, and celery, to name a few).
Despite the outbreaks that have occurred, the science still says that animal-based food products — especially unpasteurized or ready-to-eat dairy and meat products — seem to carry higher risks of listeria contamination than other foods.
Here it helps to recap how listeria bacteria spread in food. Listeria bacteria can live in many foods, but not in quantities that would necessarily make a person sick. Over time, though, the bacteria may grow if left in the right environment. And the more of the bacteria in a food, the greater a person’s risk of infection.
Dr. Harris says that cooking food kills listeria, but (unlike with other bacteria) refrigeration does not necessarily kill listeria or stop it from growing.
This is why ready-to-eat dairy and meat products — stuff that isn’t cooked or heated and tends to sit around in our refrigerators for weeks — seem to be common sources of listeria-related infections.
Foods to Avoid to Avoid Listeria Infection
You’ve probably already picked up a few important tips when it comes to avoiding Listeria monocytogenes, which is the species of listeria bacteria that causes health problems in humans.
- Soft and Raw-Milk Cheeses
“Avoid eating higher-risk foods such as soft and raw-milk cheeses,” Harris says. Dr. Hunter agrees, and singles out unpasteurized dairy products — particularly queso fresco cheeses — as especially risky. Soft cheeses made with unpasteurized milk may be up to 160 times more likely than other foods to harbor Listeria monocytogenes bacteria.
Both Harris and Hunter also mention raw sprouts as a source of concern. Sprouts require warm, humid conditions to grow. Listeria bacteria also thrive in these environments, making sprouts more likely to be contaminated. Also, sprouts typically aren’t cooked, which would otherwise kill harmful bacteria. Especially when eating out or buying premade foods, avoid sprouts or, as a safeguard, ask your server not to garnish your meal with them.
When it comes to meat-based products, deli meats and hot dogs are more likely than other foods to be contaminated with listeria. The same is true for dried sausages, packaged cold cuts, and meat products that don’t require heating or cooking.
The CDC recommends that people at high risk for a listeria infection avoid these foods entirely. For healthy adults, these meat products should be stored unopened for no more than two weeks — and consumed within three to five days after they’re opened.
- Store-Cut Melon and Smoked Seafood
Store-cut melon and smoked seafood products are also risky, and are probably worth avoiding for people at high risk for listeriosis.
More Ways to Avoid Listeria
Harris also recommends following “good food handling practices.” Keep your kitchen and cooking utensils clean, and properly refrigerate and store food. Don’t leave cooked or cut-up foods sitting around at room temperature if you’re not eating them, she says. (Listeria bacteria grow much faster at room temperature than they are able to grow at refrigerator temperatures.)
And stay on the lookout for smaller listeria outbreaks not reported in the news. Big listeria outbreaks do tend to make headlines, whereas small or local outbreaks may not. If you want to keep track of any food-related health issues in your area, the U.S. Department of Health and Human Services offers information about all food-related recalls and health issues at Foodsafety.gov. There, you can sign up for automatic alerts about listeria concerns in your area.
It’s also good to keep in mind that listeria outbreaks are rare. But if you’re not paying attention or taking care to avoid risky foods, you may be in danger — especially if you’re pregnant, older than age 65, or have a weakened immune system.