[Maternal factors associated to congenital transmission of Chagas disease in children born and siblings in Chaco province, Argentina.]

Introduction: After vector-borne transmission, the congenital form is the most important to maintain the endemic. The probability of congenital transmission may depend on factors that vary between different countries and geographic areas. This study was carried out with the objective of estimating the proportion of congenital transmission of Chagas disease and maternal factors associated to the T. cruzi infection in newborns and their siblings during 2011 in four hospitals of the Province of Chaco.

Methods: A cross sectional study was performed. A home visit was made to children aged above 10 months born during 2011 whom their mother present T cruzi infection. Blood samples were taken from both the newborns and their siblings and were processed for diagnosis of T. cruzi infection with HAI and ELISA. We found 247 mothers infected with T cruzi, and blood samples were obtained from 246 newborns and 556 of their siblings.

Results: Of the 246 children born in 2011, a total of 6.1% (95% CI = 3.6-9.6) resulted with positive serology, as well as 7.7% of their siblings (95% CI = 5.7-10.1) and the clinic visits of those born in 2011 and their siblings in the health center was associated with a lower probability of congenital transmission (OR = 0.21 and 0.36, respectively).

Conclusions: The transmission rate is consistent with the values reported in Argentina and only multiparity was a mother factor associated with the higher probability of congenital transmission.