OB/GYN – “So now that you’re pregnant, you should stay away from alcohol, illicit drugs, caffeine, swordfish or tilefish, raw fish sushi, cigarettes, deli meats and soft cheeses… gain 25-35 lbs throughout your last two trimesters, try to eat healthy, exercise regularly, take a folic acid supplement, also a DHA/Fish oil supplement, a prenatal vitamin, ….”

Newly Pregnant Woman – “Sure, yeah, ok, got it” 

Somewhere along that whole spiel of overwhelming information, the deli meats and soft cheeses point may have been lost. Sound familiar?

I mentioned in this week’s WSDW post that I was considering writing about listeria poisoning (& its relevancy with pregnancy precautions) because of a family friend who recently died of listeria poisoning. If you want to read about it, the FDA recall of his suspected exposures is described here. It’s been an extremely awful and painfully devastating experience that this family has been through. And who would’ve even guessed that it could come from a popular ice cream distributor that sells to nursing homes, hospitals, and schools? It’s absolutely frightening. Mom and Dad, this post is dedicated to you. 

So let’s talk listeria.

Not familiar with the word/term? Listeria Monocytogenes (“listeria”) is a bacteria that is found in contaminated water, soil, plants, and food.

Listeriosis is the term used to refer to an infection caused by that bacteria,

The Stats (Published by the CDC)

Honestly, these stats weren’t convincing to me that listeria was something to be worried about, as there are so many other things to be careful of during pregnancy and breastfeeding. Keep in mind, that despite these statistics, actually becoming ill with listeriosis can be especially harmful to your growing baby during pregnancy. 

  • Rates of listeria poisoning have been declining in the United States from 1998-2012 by 42%
  • Outbreaks aren’t frequent, but in 2012, there were 4 confirmed outbreaks of listeria poisoning and 1 suspected outbreak in the United States. The largest historical outbreak of listeria contamination occurred in 2011 from a contaminated cantaloupe farm, and it affected people across 28 different states and resulted in 1 miscarriage, 33 deaths, and 147 listeria-identified illnesses
  • In 2013, it was calculated that for every 100,000 people in the United States, only 0.26 incidences (new onset of illness) of listeria poisoning would occur (average annual incidence). That’s 26 cases per 10 million people

Doesn’t seem like a big deal, right? If it’s so rare, then why even bother? Well, read on. 

How does Listeria Poisoning Differ from Other Food Poisoning?

Here are some general stats:

  • 1600 people in the US get sick each year from listeria contamination 
  • Listeria is the 3rd leading cause of death from food poisoning
  • 90% of those who get Listeria infections are pregnant women and their newborns, people 65 or older, and those with chronic health conditions and weakened immune systems
  • Most cases of listeria poisoning require hospitalization
  • 1 in every 5 cases of listeria poisoning results in death

Why are Pregnant Women more “At risk”? 

It’s not the mom that’s the vulnerable target, it’s the little baby growing and developing inside of her. Remember, baby doesn’t have a strong system to ward off harmful bacteria, so although the mom may not know she has consumed contaminated food, her baby could be harmed. There is a 20% mortality rate (rate of dying) with a listeria infection in stillbirth pregnancy. Johns Hopkins identifies the 3rd trimester to be the most common with the most serious cases (of listeriosis). The bacteria is transmitted through the placenta to baby and can lead to:

  • Miscarriage
  • Stillbirth (delivering a baby that has already died in the uterus)
  • Premature delivery
  • Serious illness or death in newborns
  • Health problems for the baby

Like most infections, people in “high-risk groups,” who have weakened immune systems (the elderly, those with a chronic illness) are more at-risk of a serious or fatal case. Pregnant women are included in this high-risk grouping because their baby’s defenses are not strong and pregnancy is considered a phase in which the immune system is weakened.

In general, people may not experience symptoms of listeria poisoning until days or even weeks after eating contaminated food. If they are symptomatic, it may present in a very mild manner, such that they may not even feel ill at all. If you are in a high-risk group, that illness is exponentially worsened, and outcomes are not as hopeful.

That’s why it’s especially important for pregnant women to stay away from foods that may be contaminated, to ensure the safety of their baby. And, if they do experience any flu-like symptoms up to a couple months after eating contaminated food, to report it to their obstetrician immediately. 

What Precautions Should I take if I’m Pregnant? What Foods May Be Contaminated with Listeria?

Listeria contamination is often found on foods that we don’t cook before eating. It is a really hard bacteria to get rid of and can grow and survive in refrigerated environments. The bacteria can remain hidden on food preparation equipment and surfaces. 

The following is found on the CDC’s (Centers for Disease Control and Prevention) website regarding Listeria and Pregnancy Infection

  • Do not eat hot dogs, luncheon meats, or deli meats unless they are reheated until steaming hot.
  • Avoid getting fluid from hot dog packages on other foods, utensils, and food preparation surfaces
  • Wash hands after handling hot dogs, luncheon meats, and deli meats.
  • Do not eat soft cheeses such as feta, Brie, and Camembert, blue-veined cheeses, or Mexican-style cheeses such as queso blanco, queso fresco, and Panela, unless they have labels that clearly state they are made from pasteurized milk. (Trader Joe’s was my haven for soft-cheeses! All of their cheese is made from pasteurized milk, including brie, blue cheese, and everything in between)
    • It is safe to eat hard cheeses, semi-soft cheeses such as mozzarella, pasteurized processed cheese slices and spreads, cream cheese, and cottage cheese.
    • PASTEURIZED MEXICAN-STYLE CHEESES like Queso Fresco, are also still likely contaminated during cheese making and have caused listeria infections! (CDC, here)
  • Do not eat refrigerated pâté or meat spreads. 
    • It is safe to eat canned or shelf-stable pâté and meat spreads.
  • Do not eat refrigerated smoked seafood unless it is an ingredient in a cooked dish such as a casserole. Examples of refrigerated smoked seafood include salmon, trout, whitefish, cod, tuna, and mackerel which are most often labeled as “nova-style,” “lox,” “kippered,” “smoked,” or “jerky.” This fish is found in the refrigerated section or sold at deli counters of grocery stores and delicatessens. 
    • It is safe to eat canned fish such as salmon and tuna or shelf-stable smoked seafood.
  • Do not drink raw (unpasteurized) milk or eat foods that contain unpasteurized milk.
  • Use all refrigerated perishable items that are precooked or ready-to-eat as soon as possible.
  • Clean your refrigerator regularly.
  • Use a refrigerator thermometer to make sure that the refrigerator always stays at 40 °F or below.
  • Report symptoms immediately (below) to your obstetrician.

Image source:

It is a bit scary that listeria contamination can happen with pretty much any food (contaminated peaches, ice cream, celery, cantaloupes, tomatoes), but the foods that are listed above are the foods in which listeria is most often found.

Symptoms to Watch For During Pregnancy

  • Chills
  • Fever (usually anything above 101 F, but ask your OB/GYN)
  • Muscle aches
  • Diarrhea/Nausea (more than 2-3 loose stools lasting for more than 24 hours)
  • Upset stomach

Remember, as an otherwise healthy pregnant person, you may not feel very symptomatic (don’t we get hot flashes a lot anyway while pregnant? Nausea? GI issues? So many normal pregnancy-symptoms could mask a foodborne illness!)

What Will the Doctors Do if I Think I’m Infected?

They can perform a blood test to confirm listeria poisoning. The strain of listeria poisoning can be isolated from that blood sample and compared to the strains reported to the CDC for any suspicious food you’ve eaten. Per the CDC, often with miscarriages, it is difficult to determine the source food, since miscarriages can occur weeks after the initial infection. 

It is tempting to think, “well, there are so many other foodbourne illnesses that occur, listeria is just one of them,” but illness from listeria can be far worse than some vomiting, diarrhea, and fever over the course of a few days like a typical food poisoning case. The bacterial infection from listeria can spread to the major organs (heart, liver, etc) and on to the nervous system (brain) causing meningitis, brain abscess.

Treatment for Listeria During Pregnancy

According to the CDC and Johns Hopkins, intravenous (in your vein) antibiotic therapy is the first go-to for treatment of Listeria poisoning. Since your pregnancy classifies you as an extra special card-holding member of a high-risk category, you would be prescribed antibiotics even if you aren’t experiencing symptoms.  

So a Little Anecdote to End this Post

In the middle of my pregnancy, I asked a fellow pregnant co-worker of mine who is an ICU nurse, if she was eating deli meats. I’d noticed that during night shift, she would buy from our hospital’s Subway, and I was pretty sure that none of us would’ve asked our grumpy-at-1 AM-Subway-crew members to heat the meat until steaming hot prior to making our sandwich. She said that her OB told her it was OK as long as she only ate deli meats from a reputable sandwich shop. I honestly felt like the chances of a listeria contamination were so rare, that I should be fine eating at Subway or Jimmy John’s etc. Besides, I’ve had my fair share of food poisoning experiences to “know” if I was coming down with food poisoning.

Shockingly, I actually didn’t even look deeper into listeria poisoning when I was pregnant. I left the listeria teachings and “warnings” I remember learning in Dietetics with my otherwise half-witted pregnancy brain!

Now, I didn’t go hog wild with eating Jimmy John’s or Subway, but I did enjoy it occasionally. After writing this post, I consider us lucky, despite the low-risk high-severity situation with listeriosis. 

Thankfully Trader Joe’s will always be my easy go-to pasteurized soft cheese (and everything else) haven, especially back when I was pregnant! No more deli sandwiches! This is one of those “do as I say, not as did” cases. Right? 

Sources: Listeria Infections – Listeria Statistics – Listeria Recipe for Infection –

Johns Hopkins: Hopkins Antibiotics Guide – Listeria Monocytogenes –