Listeria Infection in Pregnancy
A Deadly Bacteria
Although listeriosis often goes unnoticed in healthy people who aren't pregnant, the ill-effects and risks for a pregnant woman and her unborn baby are very substantial. The greatest peril is to the unborn baby coming in the form of increased risk of miscarriage, stillbirth or premature labor. Newborns suffer the most from the illness as they contract it when the mother eats contaminated food during pregnancy. The death rate for newborns with Listeria is 25 to 50 percent. However, if the mother is treated with antibiotics soon after contamination, the chances are good the baby will be born without serious problems.
Foods to Avoid In Pregnancy
Listeria infection (Iisteriosis) is an illness that results from eating foods that are contaminated with the Listeria monocytogenes bacteria. Some foods tend to be more prone to contamination than others and these are the foods pregnant women should exclude from their diets - at least for the duration of the time they are pregnant and while breastfeeding. The following is a short list of some of the foods to avoid while pregnant that may carry listeria bacteria:
· Soft cheeses like camembert, ricotta, feta and brie are safe if they are served cooked and hot or unless they are marked clearly as being pasteurized.
· Prepared, precooked, cold foods that are not reheated such as prepared salads, deli meats like ham and salami, quiches and pates. Refrigerated pates or meat spreads should be avoided, eat only pates and spreads that are canned or shelf-stable.
· Hot dogs or lunch meats need to be heated to a temperature sufficient to kill Listeria bacteria. Avoid getting the liquid from hot dog packages on other food.
· Do not eat refrigerated smoked seafood such as those labeled: nova-style, lox, kippered, or jerky. Canned or shelf-stable smoked seafood is alright to eat.
· Raw seafood like oysters and sashimi
· Soft-serve ice cream
The organism that is the cause of the listeria infection is destroyed by heat, so be sure to heat foods that can be heated to the point of steaming hot in order to ensure the bacteria is killed.
Listeria is found in soil and water which means that vegetables can become contaminated with the bacteria either from the soil or from manure that is used as fertilizer. Animals can be carriers of the bacterium without any signs of illness thus causing contamination of foods of animal origin like meats and dairy products. Unpasteurized products can carry the bacteria as well. Listeria is killed by pasteurization and cooking. However, foods that are precooked and then packaged can be susceptible to the bacterium which is why they must be cooked thoroughly before inclusion in a pregnancy diet.
Danger to Mother and Baby!
While adults get listeriosis through eating contaminated products, babies born with the illness get it through their mother's bloodstream or through a colonized genital tract (Silver, 1998). If a pregnant woman contracts listeriosis, she may have premature delivery, miscarriage, stillbirth or serious health problems for the newborn.
Pregnant women are 20 times more likely to get listeriosis than the average adult. The body defends itself against listeria by depending upon lymphocytes called T-cells as opposed to antibodies. Individuals with suppressed cell-mediated immunity (low T-cells) are more susceptible to the effects of listeria. The immune system of pregnant women is naturally depressed cell-mediated thus putting her at greater risk. Of course, the immature and delicate immune system of the pre-born and newborn baby is even more susceptible.
Newborns that have early-onset (less than seven days) listeriosis are usually diagnosed within 24 hours of birth with blood infection. It is most frequently acquired by transmission through the placenta. Late-onset (seven days or more) listeriosis may present with poor feeding, irritability and fever. This infection can be treated with antibiotics quite successfully. When the mother contracts the infection during pregnancy prompt administration of antibiotics often prevents passing the infection to the baby. Babies with the infection are also given antibiotics, the same as the mother.
Foods To Avoid
Prevention is the best course of action. In order to prevent listeriosis the CDC recommendations are:
· Thoroughly cook raw foods from animal sources (beef, pork or poultry)
· Wash raw vegetables thoroughly before eating them
· Separate uncooked meats from cooked foods, ready-to-eat foods and vegetables
· Avoid unpasteurized dairy or foods made from unpasteurized dairy
· Eat perishable ready-to-eat food as soon as possible
· After handling uncooked meats, wash hands, cutting boards and knives as soon as possible
To find out more about what foods are best during pregnancy, check out our article in this section.