Listeriosis in Pregnancy

In pregnant women, in which hormonal changes make the immune system more susceptible, listeriosis occurs in asymptomatic or mild form, but can cause, in severe cases, miscarriage, stillbirth of the fetus, premature birth and neonatal infections. Listeriosis can occur at any time during pregnancy but has been most frequently documented during the third trimester. Symptoms may not be specific and can often manifest only as a flu-like syndrome (fever, headache, bone and muscle pain, vomiting/diarrhea); these symptoms are associated with the bacteraemic phase of the infection and are an excellent time to obtain blood cultures to diagnose. Fetal infection can occur by transplacental hematogenous transmission during the phase of maternal bacteremia, with passage of L. monocytogenes into the fetal circulation or amniotic fluid. Asymptomatic localization in the female genital tracts is possible. Intrauterine infection can cause: premature birth, amniotic fluid infection, abortion, neonatal infection, neonatal death. It is difficult to estimate the percentage of aborted fetuses that can be attributed to an infection caused by L. monocytogenes during pregnancy, as bacterial cultures from aborted fetuses or premature babies are not routinely performed. It is not necessary to submit patients with a history of pregnancy associated with listeriosis to microbiological screening or antimicrobial prophylaxis, but it is important to provide advice to avoid the consumption of foods with a high risk of contamination (see the infographic). Given the potential negative consequences of listeriosis on the fetus it is prudent to evaluate all febrile episodes during gestation with blood cultures. To trace the cause of the infection, it is useful to know the foods consumed by the patient in the thirty days prior to the onset of symptoms. Due to the serious consequences for the fetus, a rapid diagnosis of listeriosis, which allows prompt antibiotic treatment of the pregnant women, is essential. Diagnosis of listeriosis in pregnancy can be difficult due to the lack and non-specificity of symptoms.