Patients whose immune system is deficient in people over 60 years, clinical symptoms may be more severe (bacteremia, septicemia, meningitis), leading to an almost systematic hospitalization .
In pregnant women, listeriosis leads to a difficult pregnancy and causes damage to the foetus up to its death in the utero.
It is a notifiable disease.
Listeriosis in pregnancy: what are the health issues?
Anyone can get listeriosis, especially since there is no sustainable immunization, in contrast to toxoplasmosis: having had a listeriosis do not protect us against a new infection. Healthy carriers exist, they excrete the bacteria but are not sick. Little dangerous bacteria for healthy adults, the disease remains rare – fewer than 4 cases per million inhabitants in France for example – it is still fatal in 20-30% of cases (figures Institut Pasteur, Paris).
The incidence in the general population reported by the Epidemiological Network EPIBAC of invasive Listeria monocytogenes increased in 2009 (0.60 cases per 100 000) from 2008 (0.46 cases per 100 000) (p <10-2 ) and thus returns to the level observed in 2007 (0.53 cases per 100 000) (p = 0.2).
The total number of cases of maternal and newborn was 43 in 2010 (figures InVS), including 4 foetal deaths and 10 stillbirths. Evening 5.2 cases per 100 000 births. These figures are stable thanks to information campaigns on listeriosis in pregnant women.
Listeriosis in pregnancy: what are the mechanisms?
Listeriosis is primarily transmitted by contaminated foods: shredded cheese sold in the raw milk or soft cheese, cold cuts, meats, fruits, vegetables and seafood, particularly raw fish. The bacteria pass through the intestinal wall and spreads throughout the body via the bloodstream with a particular tropism for the nervous system: meningitis, encephalitis …
The incubation period between the consumption of contaminated food and the development of maternal listeriosis ranges from a few days to two months.
During pregnancy, the listeria infects the nervous system and lungs through the placenta . It brings a placenta and amniotic fluid, miscarriage and death in utero, and this becomes more and more common with an advancing pregnancy.
Another route of transmission is the contamination of the baby during vaginal delivery:the natural passage through an infected vagina.
What are the symptoms of listeriosis during pregnancy?
In pregnant women, the symptoms of listeriosis are often very obvious: common digestive disorders, vague flu-like syndrome. Any low-grade fever (slight elevation of body temperature around 38 ° C) should alert. Any flu-like, with headaches, muscle pain in stomach or with vomiting, nausea states or fatigue with no clear reason justifies an immediate consultation of general practitioner, gynecologist or midwife.
Sometimes no discomfort is no reason to make the diagnosis which is only revealed at birth after months of an insidious infection. The birth cures the mother of her latent infection.
Contractions and a miscarriage early in the first months of pregnancy should always evoke it. In the second quarter, the miscarriage condemns the child, often stillborn. Later preterm birth reveales a seriously ill newborn sepsis, respiratory distress and / or neurological disorders (meningitis).