The present article looks at the
association between the epidemiological
history of
women infected with
Trypanosoma cruzi and the
risk of vertical
transmission. Eighty-three chronically infected
mothers and their 237
children were studied, using a cohort design. All
patients reside in Santa Fe city,
Argentina. Twenty-five
women transmitted the
infection to 38
children. The potential
risk factors evaluated in the
mothers were exposure to vector
transmission,
blood transfusion history, maternal seropositivity,
parasitemia and age at
birth of the
child. 72% (18/25) of the
mothers who transmitted the
infection to their
children, had little or no contact with the vector, while only 28% (7/25) of the
mothers presented a
history of medium or high
risk of vector
infection. The differences were significant (p < 0.05). Forty-one percent of the
women who presented maternal
history as the probable route of
infection, transmitted the
parasite to more than one
child (1.86 ± 0.33; CI95% = 1.03-2.68). In addition, the most frequent
history, among the
women who transmitted the
disease to their
children, was the absence of exposure to vector
transmission and transfusion with unknown maternal
serology. The route of
infection was probably transplacental. These observations suggest that there are
family genetic characteristics involved in vertical
transmission. The
parasite was found in 71% of the
mothers who transmitted the
infection to their
children and were able to perform
xenodiagnoses. After controlling for the other variables, the
logistic regression analysis showed that
xenodiagnosis (+) is a
risk factor for
congenital transmission; the
relative risk was 12.2 (95%
confidence interval 2.9 - 50.1). No differences were found when analyzing the
mother's age and transfusion
history. The highest
risk of
congenital transmission was associated with detectable
parasitemia and less
maternal exposure to the vector.