Congenital transmission of Trypanosoma cruzi in central Brazil. A study of 1,211 individuals born to infected mothers

Abstract

Transmission of Trypanosoma cruzi during pregnancy is estimated to occur in less than 20% of infected mothers; however, the etiopathogenesis is not completely understood. The Centre for Studies on Chagas Disease provides confirmation of T. cruzi infection for individuals living in central Brazil. In this retrospective hospital-based study, all requests for diagnosis of T. cruzi infection in individuals less than 21 years old from 1994-2014 were searched. We end with 1,211 individuals and their respective infected mothers. Congenital transmission of infection was confirmed in 24 individuals (2%) in central Brazil, an area where the main T. cruzi lineage circulating in humans is TcII. This low prevalence of congenital Chagas disease is discussed in relation to recent findings in the south region of Brazil, where TcV is the main lineage and congenital transmission has a higher prevalence (approximately 5%), similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first report to show geographical differences in the rates of congenital transmission of T. cruzi and the relationship between the prevalence of congenital transmission and the type of Tc prevalent in each region.

2 nd Brazilian Consensus on Chagas Disease, 2015

“…This suggests that the presence of TcII in the study area may be associated with lower rates of transmission than TcV, which predominates in the southern regions of Brazil and other Southern Cone countries, where the vertical transmission rates are generally known (108) . Despite existing scientific evidence, important gaps remain in terms of the role of genetic diversity of T. cruzi in relation to the evolution of the chronic phase of the disease, the risk of congenital transmission or reactivation, and the occurrence of oral outbreaks transmission (27) .…”

Putting Infection Dynamics at the Heart of Chagas Disease

“…Parasitemia clearly fluctuates because PCR analysis is not consistently positive or negative in individuals over time [10]. T. cruzi can also cross the placenta leading to congenital transmission in ~5% of cases, with some geographic variability linked to T. cruzi genotype [79]. As outlined below, parasites have been detected in a wide of range of other organs, but whether any of these sites serve as genuine long-term reservoirs, or simply become transiently infected is far from clear.…”

Congenital Transmission of Trypanosoma cruzi in Argentina, Honduras, and Mexico: An Observational Prospective Study

“…9 It has been suggested that the congenital transmission rate might vary according to the parasite's genotype, but available data are inconclusive. [10][11][12][13] Trypanosoma cruzi genotypes have been grouped into discrete typing units (DTUs), with TcI being assumed to be more frequent in Mexico and Central America and non-TcI (TcII-VI) being dominant in the Southern Cone region of South America. 14,15 However, recent studies suggest that TcI might not be predominant in all regions of Mexico.…”