Listeria monocytogenes, a bacteria widely found in the environment, causes the infection listeriosis. In the United States, about 2,500 people become seriously ill and about 500 die each year from listeriosis. Pregnant women are 20 times more likely to be infected than other healthy adults. Newborns and people with compromised immune systems also are susceptible to the infection. The most common cause of listeriosis is eating foods contaminated with the bacteria.
If a pregnant woman has been infected with listeria, she may not show any symptoms and therefore may not even know. Other times, mother-to-be can show flu-like symptoms (fever, chills, body aches), back ache, headaches, diarrhea, stiff neck, confusion and dizziness. If a pregnant woman is infected with listeria, it can negatively affect her baby while still in the womb or shortly after birth.
If the infection occurs early in the pregnancy, it may create a miscarriage, even before the woman knows she was pregnant. If the infection occurs later in the pregnancy, it may result in a stillbirth.
Infection of the Placenta and/or Amniotic Fluid
The placenta provides nutrition and oxygen to the fetus. The amniotic fluid protects the fetus from infection. If either of these is infected with listeria, it can not do its job. The fetus will not receive adequate nutrition or oxygen, preventing proper growth and development. The fetus also will be at risk of infection.
Listeriosis of the placenta, amniotic fluid, or fetus can result in preterm birth (before 37 weeks). Babies born too early are at risk of respiratory issues, heart problems, intestinal problems and even death.
Infection of Fetus or Newborn
A baby can be born with listeriosis or develop the infection a few days after birth from an exposure while inside the uterus. Problems of babies with listeriosis include blood infection, difficulty breathing, fever, skin sores, lesions on multiple organs, and meningitis (an infection of the membranes surrounding the brain). These babies may have long-term complications or die.
Pregnant woman can minimize their risk of listeriosis by avoiding the following foods: raw fish, shellfish and fish products, raw meat and poultry, hot dogs, deli meats, raw and processed vegetables, unpasteurized soft cheeses, blue-veined cheeses, unpasteurized goat and sheep's milk, coleslaw, chilled foods made for reheating. When reheating a food, it should be reheated until steaming hot. A simple blood test can determine if the mother has the infection.