Should I Check for Lysteria?


Dear Nutritionist,
I ate a little bit of unpasteurized cheese while in Canada at 6 weeks pregnant. Is there anything I should do to make sure it did not contain listeria?


I am not sure how long ago it was that you ate the cheese, but symptoms of the food borne illness, listeria, usually become apparent at around 4 to 21 days after ingestion, though it can also be as long as 10 weeks. A person with listeriosis usually exhibits fever, muscle aches, and gastrointestinal symptoms such as nausea or diarrhea.

Infected pregnant women will ordinarily experience only mild, flu-like symptoms. However, infection during pregnancy can be dangerous in that it can lead to miscarriage, infection of the newborn, or even stillbirth. Doctors diagnose a fever or flu-like illness as listeria infection by swabbing a sample from the vagina and cervix and checking the mother's blood. Antibiotics are used to treat the infection.

It might be too late to know if the product you ingested actually contained listeria. Depending on the length of time since you ate the cheese, you probably would have had symptoms by now. If you are concerned I would contact your doctor!

Check out information from the Center for Disease Control: Knowing how to decrease your risk for this food borne illness will help with food choices you make in the future during your pregnancy!

Thanks for your question!

-- Kimberly, RD LD

Kimberly Tessmer

Kimberly A. Tessmer, RD LD has been a registered dietitian since 1992 and is also an Ohio licensed Dietitian. Her educational achievements include a Bachelor of Science in Technology (Dietetics) from Bowling State University in Bowling Green, OH. She currently owns and operates a consulting business called "Nutrition Focus", in which she specializes and offers services in the areas of weight management, general nutrition, authoring, menu development and a variety of other services.

To date Kim has authored three books including "The Everything® Nutrition Book", "Tell Me What To Eat If I Have Celiac Disease", and "The Everything® Pregnancy Nutrition Book". In addition, Kim has written numerous articles for various health/nutrition web sites and magazines including Bally Total Fitness Magazine, Well and Healthy Women Magazine and, Inc as well as continuing education courses for She is a member of the American Dietetic Association and the ADA Practice Group, Nutrition Entrepreneurs.