The recent news media's focus on food recalls due to contamination with the bacteria known as listeria monocytogenes has rightly identified an at-risk group: pregnant women. These types of outbreaks are not so uncommon, but they are usually limited and contained by various government measures via the FDA's alerts to keep our food safe. However, when an outbreak is noted, it is the higher risk groups of people who need to really take notice. Pregnant women are nearly always more likely to have problems. Not only must they deal with the infection in their own body, but they also have to be concerned about the infection being transmitted across the placenta to the baby.
A full-blown listeria infection in a pregnant woman can result in preterm birth, miscarriage or stillbirth, so treatment of a recognized infection using intravenous antibiotics (penicillin or sulfa antibiotics are effective) is important to prevent fetal problems and can even be life-saving. Unfortunately, there is no vaccination against listeria, but prevention of exposure by following some basic, standard food safety measures is key. The symptoms of infection are vague and common to many viral illnesses to include fever, aching muscles, nausea/vomiting and diarrhea. They usually resolve within a week even with no treatment.
Thoroughly washing fruits and vegetables will go a long way toward removing harmful bacteria such as listeria because even refrigeration is not enough to suppress it. Thoroughly heating food such as hot dogs will also reduce the potential exposure. Keeping uncooked meats away from vegetables in the kitchen is always important along with liberal use of antibacterial wipes/cleansers/hand-washing. Pregnant women should not consume unpasteurized products at all.
If you think or know you have been exposed to listeria while you are pregnant, but you have no symptoms, you should still let your provider know. The symptoms of listeria infection can be delayed by several weeks beyond the consumption of the contaminated food.