Seroprevalence and vertical transmission of Chagas disease in a cohort of Latin-american pregnant women in a tertiary hospital in Madrid

Abstract

Chagas disease, caused by Trypanosoma cruzi (T. cruzi), is endemic in Latin-America and is emerging in Spain due to immigration. The vertical transmission rate is around 5%. A routine prenatal screening with serology of all pregnant women from endemic areas is recommended to identify infected newborns, allowing early treatment and cure. The aim of this study was to estimate the prevalence of positive Chagas serology in a cohort of pregnant women from Latin-America and its vertical transmission. An observational, prospective, follow-up study was conducted on women with positive serology to T. cruzi, as well as their newborns, from January 2013 to April 2015. Congenital Chagas was ruled out using a PCR technique at birth and at 1 month, and with serology at 9-12 months old. A child was considered infected when PCR was positive, and uninfected when PCR was negative, and/or it had a negative serology. Screening was performed on 1244 pregnant women from Latin-America, and there were positive results in 40 (prevalence 3.2%, 95% CI: 2.4-4.4%), with 85% of them from Bolivia. There was only one infected newborn (rate of vertical transmission 2.8% (95% CI: 0-15%)), who had a positive PCR at birth. Relative studies enabled an 8-year-old sister with an asymptomatic disease to be diagnosed and treated. Both were treated successfully with benznidazole (later the PCR and serology were negative). Screening during pregnancy in Latin-American women helped to detect those with Chagas disease. The rate of vertical transmission was 2.8%, in keeping with literature. Screening led to the detection and treatment of previously unidentified familial cases.