Listeriosis is a serious infection caused by a bacteria called Listeria Monocytogenes. This infection is particularly dangerous in pregnancy and can cause miscarriage, premature labor and even stillbirth.

How do I contract Listeria?

Listeria is an interesting bacteria in that it can grow in refrigerated conditions ( typically 4-6 degrees.) A pregnant lady will contract the bacteria if she consumes food contaminated with this bacteria.

So what foods should I avoid when pregnant to prevent Listeria?

Food most at risk of Listeria contamination tend to be processed oily or fatty food which we often consume chilled from the fridge. Think of anything on an anti-pasto platter for example: soft cheese, smoked meats, shellfish, pickled vegetables, pate and other meat spreads, chilled chicken and yoghurt are some examples. Never have unpasteurized dairy products in pregnancy. Also do not eat raw sprouts. These foods should never be eaten cold for the entire pregnancy.

Can I eat these foods hot?

Yes if used in cooking and properly heated through these food types can be eaten hot. Also be careful when reheating meals: make sure to thoroughly heat in a saucepan stirring regularly. Microwave reheats are unreliable often being cold in the middle.

How would I know I have Listeria?

The onset of the illness can be anywhere from 7 to 70 days after ingesting the food. Typical symptoms are fever, headache and neck stiffness, aches and pains in muscles and joints, fatigue, and diarrhea on occasion. Rarely cases have been reported where no symptoms are remembered.

How is Listeriosis diagnosed?

As the bacteria invades the blood stream, a blood sample sent for culture can grow the bacteria in a laboratory. This test takes a few days to come back. If Listeria is suspected treatment is usually commenced as soon as the blood test is taken.

How is Listeriosis treated?

Penicillin is the drug of choice, given intravenously in high doses. If you are allergic to penicillin, alternatives include Vancomycin and Erythromicin.

Remember Listeria only affects approximately 7 out of 300,000 pregnancies each year in Australia, however by avoiding the at risk foods you can go a long way to avoiding this uncommon but serious condition.

If you have concerns about Listeria, please call the rooms for an appointment.

Author: Dr Peter England, Obstetrician and Gynaecologist.
Read more about Dr Peter England

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