Chagas disease prevalence in pregnant women: migration and risk of congenital transmission

Introduction: Argentina has been a preferential target for Bolivian immigrants for decades. The relatively recent migratory flux includes Germany, France, the United States, Australia, Japan, and some Latin American countries. The aim of this cross-sectional study was to describe the prevalence of Chagas disease in pregnant women, analyzing the Bolivian-specific Chagas prevalence as the main contributor of migratory populations from Chagas disease-endemic areas to Buenos Aires city, Argentina, and to evaluate the impact of these migrant influxes on the process of the "urbanization" of the disease in reference hospital Jose Maria Ramos Mejia (JMRM). Methodology: Overall, 21,332 pregnant women (100%) between 15 and 49 years of age derived from the public maternity service of JMRMH were studied. Serology data was obtained from registered serological diagnosis data, consisting of three different serological tests performed at the Public Parasitology Unit. Results: Although general prevalence decreased during the analyzed period, the specific prevalence of pregnant women from Bolivian origin showed a sustained growth during 1983-2013. Solely 5% of the total pregnant women population from Bolivia contributed to one third of the total Chagas prevalence. Conclusions: This study showed that a cohort of pregnant women from Bolivia who attended JMRMH during the period 1983-2007 constituted a population at risk for congenital transmission. Increased migration from endemic areas of Bolivia might potentially increase the prevalence of Chagas disease among pregnant women. In addition, this study highlights the importance to analyze specific prevalence according to endemic areas to determine the profiles of potential hidden prevalence.