Efectos de la infección aguda y crónica por Trypanosoma cruzi en la gestación de los ratones / Effects of acute and chronic Trypanosoma cruzi infection in pregnant mice

Pathogens may impair reproduction in association or not with congenital infections. We have investigated the effect of acute infection with Trypanosoma cruzi, the protozoan agent of Chagas disease, on reproduction of female mice. In the acute, parasitemic, phase of the infection, female mice were totally unable to reproduce. Most of them (80%) were infertiles and did not develop any gestation. In the few gravid infected mice, implantation numbers were as in uninfected control mice. However, their fetuses presented a weight meanly reduced by 40% as compared to those of uninfected females, and all of them died during the gestation or whithin 48 h after birth. Such massive mortality did not result from congenital infection, which did not occur. The infertility and the fetal mortality occuring early in gestation (resorptions) were significantly correlated with a high maternal parasitemia, whereas later fetal mortality was associated with the presence of intracellular parasites in the utero-placental unit. The decidua was particularly receptive to T. cruzi multiplication, since this tissue harboured 125 fold more amastigotes than the maternal heart or other placental tissues. In addition, placentas of dead fetuses presented histopathological lesions (inflammatory infiltrates, fibrine deposits and ischemic necrosis). Such harmfull effects of acute infection were not observed when female mice were in the chronic phase of the infection, since these reproduce normally. Their fetuses only suffered from moderate and reversible growth retardation. These results indicate that, following the maternal parasite burden, T. cruzi infection may induce very deleterious effects on gestation.

Nivel de endemia de la infección por Trypanosoma cruzi en el lugar de residencia de la madre y desarrollo de la enfermedad de Chagas congénita en Bolivia / Endemic level of congenital Trypanosoma cruzi infection in the areas of maternal residence and the development of congenital Chagas disease in Bolivia

In Bolivia, the prevalence of infection by T. cruzi in women in fertile age can vary between 20 and 60%. The present study made in the Maternity Germin Urquidi of Cochabamba - Bolivia, it has demonstrated, that 19.9% of the mothers who go to this hospitable center to be taken care of in the childbirth, they are carrying of the infection and that 4,6% of them, they are going to transmit, by transplacentaria route, the infection to its babies. Of the 71 children born with congenital Chagas, only 47,8 % present/display some type of alteration or of development(Apgar to 1 minute low, BPN, prematuridad, pathological dismadurez) or signs (SDR, hepatomegalia, esplenomegalia, neurological signs, cardiomegalia, anasarca, petequias). When investigating the effect of the differences in the vectorial density (low, medium and high) of the zone of maternal residence, on the transmission of the infection of the mother infected to the fetus, we concluded that the rate of transmission of the congenital infection of T. cruzi is not modified by the level of endemicidad of the zone of maternal residence. By another infected new born sides whose mothers reside in zones of high endemicidad present/display, most frequently and of significant way, Apgar to 1 minute < to 7, low weight when being born and prematuridad or an association of these alterations with respiratory syndrome of distress or anasarca, when one compares them with new born of resident mothers in the zones of loss or medium endemicidad, mortality in this group is greater. These results suggest calls to account it of the mothers, in areas of high endemicidad, she is associate with a serious increase in the risk of Disease of newborn severe and mortal congenital Chagas in.