[Screening for congenital infection by Trypanosoma cruzi in France].

The importance of congenital transmission of Chagas' disease increases with its emergence in communities infected with Trypanosoma cruzi, but where vector transmission has never existed or is fully controlled through vector control campaigns. In both endemic and non-endemic areas, the rates of mother-to-child transmission (MTCT) could be the same, by 5%, generating a constant source of new cases of the disease. Risk factors for vertical transmission are not fully elucidated, but the effectiveness of the adaptive immune response and the genetic susceptibility of both the mother and the child are suspected. Besides the risk of miscarriage or premature birth, neonatal infection by T. cruzi causes an acute form of Chagas disease, which may be accompanied by a severe infectious syndrome that can causes death if not treated early. This form of the disease is a real public health priority because it is frequent, severe, identifiable and curable. Indeed, almost all newborns diagnosed and treated before the end of their first year of life will be definitely cured. In all non-endemic areas, detection of cases of congenital Chagas disease is hampered by a very low prevalence of the disease in the general population of pregnant women, the lack of symptoms in most infected women and the disregard of these problems from health personnel in charge of monitoring pregnancy. Secondary prevention firstly consists in identifying infected women (with history of exposure and positive serology for Chagas disease) and secondly to look for the parasite in newborns from infected mothers. No primary prevention is indeed possible during pregnancy, since the only two drugs are toxic and possibly teratogenic. However, after birth, treatment could be offered to all infected women in order to prevent late complications of the disease and to make an attempt at breaking the chain of MTCT in future pregnancies.