[Listeriosis and pregnancy].

Listeria monocytogenes is a ubiquitous Gram-positive bacillus widespread in nature. It is responsible for febrile abortion and encephalitis in cattle. It survives and multiplies at 4°C and does not alter the taste of food. Listeria monocytogenes is able to cross 3 host barriers: the intestinal, blood-brain and placental barriers. Maternal infection is rare but still severe in France, with 30 to 50 annual cases. Maternal infection is frequently asymptomatic, or manifests as isolated fever, whereas fetal and neonatal infection is severe and have a poor prognosis, with up to 25-35 % fetal/neonatal mortality. Amoxicillin is the reference antibiotic for listeriosis treatment and should be administered to every pregnant patient with unexplained fever, particularly in case of consumption of at risk food. Prevention in pregnant women relies on adherence to strict diet recommendations such as reheating of leftovers until steaming and avoidance of unpasteurized dairy products, cold delicatessen, meat spreads and pâtés. Listeriosis is a notifiable disease in France.