Estúdio prospectivo de la enfermedad de chagas en recien nacidos con infección placent aria por Trypanosoma cruzi (Santa Cruz-Bolivia)

Abstract

In order to know the significance of placental infection by T. cruzi 820 newborn infants (NB) weighing less than or equal to 2500 grs were examined both clinically and by the Strout method and histopathological sections of the placenta in order to detect congenital infection with Chagas' disease. Thirty five (4.26%) NB presented a placentary infections by T. cruzi, but having a negative direct parasitological examination in the cord blood, these NB were followed up parasitologically (microhematocrit), in order to detect an eventual positive change in the post-partum period. The follow-up was done at 7, 15, 30 and 60 days after birth, and with xenodiagnosis 15 days later. In 27 newborn (3.29%) it was possible to complete their follow-up with detection of T. cruzi in every case. In the control group, constituted by NB which were negative to both methods, there was no positivisation at all during the follow-up period. These observations show a high frequency of congenital T. cruzi infection in Santa Cruz.

CongenitalTrypanosoma cruziTransmission in Santa Cruz, Bolivia

“…Cord blood microscopy has a reported sensitivity of ≤60%; an additional neonatal specimen is often recommended, usually at 30 days [4]. However, programs seldom include additional specimens, because women have difficulty returning for follow-up; some programs seek additional specimens only from symptomatic infants [17, 22].…”

“…Although vectorborne T. cruzi transmission is absent, the infection prevalence is high, because the city acts as an economic magnet for migrants from rural areas with intense transmission [4, 23]. The protocol was approved by the ethics committees of the study hospital; Asociación Benéfica Proyectos en Informática, Salud, Medicina y Agricultura (Lima, Peru); Johns Hopkins University (Baltimore, MD; and the Centers for Disease Control and Prevention (Atlanta, GA).…”

“…Congenital transmission can occur from women who are themselves infected congenitally, perpetuating the disease in the absence of the vector [3]. Reported transmission rates from infected mothers vary from 1% to >10% [4–6]. Factors reported to increase risk include younger maternal age, human immunodeficiency virus infection, and (in an animal model) parasite strain [6–9].…”

An epidemiological approach to study congenital Chagas' disease

“…No case of parasitaemia was observed in a comparison group of children born to seropositive mothers with negative placentae (Azogue & Darras 1991). Considering 22.5% (8/35) of children lost to follow-up, the positive predictive value of an infected placenta for congenital transmission ranged from 77.2% (considering all children lost to follow-up as having no parasitaemia) to 100% (considering all children lost to follow-up as having parasitaemia).…”

A survey of congenital Chagas’ disease, carried out at three Health Institutions in São Paulo City, Brazil

“…The newborns may be at birth asymptomatic 5,12 . There are regional differences in the incidence rates of congenital chagasic infection, which vary from 1.1 % to 18.5% when parasitological methods are applied for diagnosis 2,3,6,22,24,26 . The risk factors for recurrent congenital transmission by chagasic pregnant women have not been clearly defined, but may be influenced by the strains of T. cruzi or the level of parasitemia 8 .…”