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

Abstract

Compared with South America, there is a lack of epidemiologic studies about the risk of congenital transmission of <i>Trypanosoma cruzi</i> in Central America and Mexico. It has been suggested that <i>T. cruzi</i> genotypes might differ by region and that congenital transmission might vary according to the parasite's genotype. Our objective was to compare <i>T. cruzi</i> congenital transmission rates in three countries. We performed an observational prospective study in 2011-2014 enrolling women at delivery in one hospital in Argentina, two hospitals in Honduras, and two hospitals in Mexico. Congenital <i>T. cruzi</i> infection was defined as the presence of one or more of the following criteria: presence of parasites in cord blood (direct parasitological microscopic examination) with positive polymerase chain reaction (PCR) in cord blood, presence of parasites in infant's blood at 4-8 weeks (direct parasitological microscopic examination), and persistence of <i>T. cruzi</i>-specific antibodies at 10 months, as measured by at least two tests. Among 28,145 enrolled women, 347 had at least one antibody rapid test positive in cord blood and a positive enzyme-linked immunosorbent assay in maternal blood. PCR in maternal blood was positive in 73.2% of the cases, and genotyping identified a majority of non-TcI in the three countries. We found no (0.0%; 95% confidence interval [CI]: 0.0, 2.0) confirmed congenital case in Honduras. Congenital transmission was 6.6% (95% CI: 3.1, 12.2) in Argentina and 6.3% (95% CI: 0.8, 20.8) in Mexico. <i>Trypanosoma cruzi</i> non-TcI predominated and risks of congenital transmission were similar in Argentina and Mexico.