Period: 2011-2013 This prospective observational study, funded by NIAID, aims to determine and compare the rate of congenital Chagas transmission of Tc I and Tc II in regions of Argentina, Honduras and Mexico. Researchers Althabe F, Sosa Estani S, Cafferatta ML. Abstract This prospective observational study, funded by NIAID, aims to determine and compare the rate of congenital Chagas transmission of Tc I and Tc II in regions of Argentina, Honduras and Mexico. To this end, samples of umbilical cord blood are obtained from all deliveries at selected hospitals for serological diagnosis of Trypanosoma cruzi through rapid tests. Blood samples of positive cases are studied by direct parasitological examination and ELISA test, and are stored and transported to the laboratory in Brussels, Belgium for PCR analysis. Babies receive neonatal clinical examinations and are followed up at 4 weeks and 10 months, facilitated through text message reminders to mothers via mobile phone. Additionally, households are mapped using a GPS unit. Blood samples are collected in tubes and filter papers, labeled using barcode labels, and stored in freezers. Temperature probes located in the freezers closely monitor cool chain conditions. Blood samples of congenitally infected children are collected in filter paper and shipped to the US to measure the Benznidazole / Nifurtimox concentration. Up to April 2013 in the Argentina site, 9,359 women were recruited, and 163 had a positive test in cord blood. Up to October 2013, 7 congenitally infected children were reported. 93% and 85% were followed up at 4 weeks and 10 months respectively. objectives Determine and compare the rate of congenital Chagas transmission of Tc I and Tc II in regions of Argentina, Honduras and Mexico. Funds NIH /NIAID – National Institute of Health/National Institute of Allergy and Infectious Diseases. Tulane University School of Public Health and Tropical Medicine / National Center on Minority Health and Health Disparities (NCMHD)/NIH Study type Prospective observational study