Chagas blot on sera from newborns. The ages of the patients are marked below each immunoblot, day (D) and month (M). T17051-4-11 and T17061-2-15: sera from 1-day-old newborns. T17051-2-07: serum from a 6-month-old baby. These three babies were born in France to three Bolivian mothers with Chagas disease. T17061-2-12: sera from an 11-month-old baby. T17061-3-10, 12, 01, 19, 06, 15 and T17051-2-12: sera, respectively, from newborns/babies aged 11 days, 2 months, 6 months, 6 months, 7 months, 11 months and 1 year. Babies born in Argentina to mothers with Chagas disease were treated at the Ricardo Gutiérrez Children’s Hospital. Arrows indicate the protein bands specifying the presence of anti-T. cruzi antibodies.