Mother-to-Child Transmission of Chagas Disease in El Salvador

Abstract

Abstract. To estimate the incidence (any mother to child) and rate (from seropositive mother to child) of motherto-child transmission of Trypanosoma cruzi, a serological census was conducted, targeting pregnant women and infants born to seropositive mothers, in four municipalities of El Salvador. Of 943 pregnant women, 36 (3.8%) were seropositive for T. cruzi. Of 36, 32 proceeded to serological tests of their infants when they became 6-8 months of age. Six infants seropositive at the age of 6-8 months further proceeded to second-stage serological test at the age of 9-16 months. As the result, one infant was congenitally infected. Thus, serological tests at the age of 6-8 months produced five false positives. To ensure earlier effective medication only for true positives, identification of seropositive infants at the age of 9-16 months is crucial. Incidence and rate of mother-to-child transmission were 0.14 (per 100 person-years) and 4.0%, respectively. Estimated number of children infected through mother-to-child transmission in El Salvador (170 per year) was much higher than that of human immunodeficiency virus (HIV; seven per year). It is recommended that serological testing for T. cruzi be integrated into those for HIV and syphilis as part of antenatal care package.

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

“…[6][7][8] A recent study identified one case of congenital Chagas disease among 32 infected mothers in El Salvador. 9 It has been suggested that the congenital transmission rate might vary according to the parasite's genotype, but available data are inconclusive. [10][11][12][13] Trypanosoma cruzi genotypes have been grouped into discrete typing units (DTUs), with TcI being assumed to be more frequent in Mexico and Central America and non-TcI (TcII-VI) being dominant in the Southern Cone region of South America.…”

Elevated Pediatric Chagas Disease Burden Complicated by Concomitant Intestinal Parasites and Malnutrition in El Salvador

“…This serosurvey identified 2.3% of children were reactive on two different antibody assays. The last surveillance efforts were performed in 2008–2011: 1% prevalence in children <16 years [ 31 ], 4% prevalence among pregnant mothers with a 3% congenital transmission rate [ 11 ], and a total of 731 acute cases continually reported from 2000–2012 [ 10 ]. In comparison, an El Salvadorian blood bank surveillance study of adults found a continual decline in annual positivity from 3.7% to 1.7% during 2001–2011 [ 12 ].…”

“…The transmission source of these chronic pediatric Chagas disease cases is believed to be vectorial; however, the potential for mother-to-child transmission cannot be ruled out. This study was unable to serologically test mothers for Chagas disease, and the latest estimates suggest approximately 3% of infected mothers will congenitally transmit infection to their infants [ 11 ]. This study was also unable to establish seasonality related to vector activity since seroprevalence does not indicate acute infection.…”

“…Considering the hyperendemicity of domestic triatomine species in this region [ 19 , 31 ], the high prevalence of acute pediatric cases diagnosed by the Ministry of Health [ 10 ], and the study’s finding of dog species present in home increasing risk (as a known risk factor for vector-human transmission cycles [ 24 , 33 , 34 ]), one would determine that a mixture of both transmission sources is responsible. As previously highlighted [ 11 , 35 ], the need for Chagas disease surveillance in pediatrics and women of childbearing age is warranted. The low number of Chagas disease seropositive children was a potential limitation, and future studies should validate these findings.…”

“…Rhodnius prolixus was the dominant domestic vector species associated with the majority of transmissions, and its eradication in June 2010 was believed to hold great promise for halting vector-borne transmission countrywide [ 9 ]. Despite this public health success, prospective investigations revealed a high incidence of acute Chagas disease [ 10 , 11 , 12 , 13 ]. The last national prevalence investigations concluded in 2011 [ 12 ], leaving a gap in current burden estimates as a new domestic vector species has since established a stronghold in the region [ 14 , 15 ].…”