Editor’s Note: Today’s guest contributor, Katya, is a nurse-midwife who asked a simple question and found herself on a mission to improve food safety in pregnancy. 

Nurse-midwives engage in disease prevention and health education as a hallmark of our profession. Avoiding listeriosis is a key component of food safety during pregnancy. Listeria monocytogenes is a rare foodborne pathogen that can get passed to fetuses and newborns, and lead to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn. The risk of getting listeriosis is 10 times higher for pregnant women than for other people, and it currently has no cure.

To prevent listeriosis, pregnant women should avoid foods designated “high-risk” for harboring the pathogen. If you think health care providers know which foods are “high-risk”, then think again.

As a student nurse-midwife, I noticed that the foods making headlines for Listeria outbreaks were different than the foods listed in medical guidelines. Accurate guidelines save lives, but I learned that these guidelines were last examined more than twenty years ago. My daughter and her best friend needed a science fair project, so I encouraged them to comb through federal databases with decades worth of data. Valentina and Rachel analyzed more than 850 entries to find an answer to a simple question: Where has Listeria been found lately?

We found that 95% of recent listeriosis cases were caused by foods outside the medical guidelines. Since Listeria clings to food processing equipment, it contaminates ready-made salads and deli dinners. Frozen foods also emerged as a culprit, since killing the pathogen requires thorough heating. Listeria even lurks in pasteurized dairy products, such as cream cheese and ice cream, indicating a need for increased in-store inspections.

As the pathogen moved into unexpected foods, the number of people sick with listeriosis doubled between 2007 and 2014, escalating to 96 pregnant women. Our study determined that the current guidelines need updating. Several “high-risk” foods were not available 20 years ago, demonstrating that a dynamic food supply requires dynamic food safety guidelines.

Now, I tell my patients: “If you didn’t make it, and you can’t heat it, don’t eat it!”

Dr. Robert Buchanan, a food safety expert at the University of Maryland, who provided us with guidance, also strongly recommends that you:

• Monitor your refrigerator temperature to make sure it is operating below 40˚F.
• Throw away high-risk foods after 3-4 days, or freeze them if you need to store them longer.
• Use safe minimum cooking temperatures and times for meat, eggs, seafood, and leftovers and casseroles (which applies to ready-made meals).
• Follow the cooking instructions on frozen foods—precisely, as listed.

If you’re pregnant, make sure to protect yourself and your baby by learning more about:

• Listeriosis symptoms and diagnosis and treatment
• Current medical guidelines on which foods to avoid
• General food safety practices

 

About Katya and the research team:

With guidance from Dr. Buchanan, and midwifery professors, Rebeca Barroso of the University of Minnesota and Mickey Gillmor of the University of Georgia, the team published their conclusions in the “Journal of Midwifery and Women’s Health”. You can watch Katya, Valentina, and Rachel talk about their research in a recent WebMD video. 

 

Simon, K., Simon, V., Rosenzweig, R., Barroso, R., & Gillmor-Kahn, M. (2018). Listeria, Then and Now: A Call to Reevaluate Patient Teaching Based on Analysis of US Federal Databases, 1998-2016. Journal of Midwifery & Women’s Health, 63(3), 301-308. doi:10.1111/jmwh.12757