Sustained Domestic Vector Exposure Is Associated With Increased Chagas Cardiomyopathy Risk but Decreased Parasitemia and Congenital Transmission Risk Among Young Women in Bolivia

Abstract

We hypothesize that repeated vector-borne infection sustains antigen exposure and the consequent inflammatory response at a higher chronic level, increasing cardiac morbidity, but possibly enabling exposed women to control parasitemia in the face of pregnancy-induced Th2 polarization.

Reply to Henao-Martínez, et al

“…I agree with Henao-Martínez [1] that to decrease congenital transmission of T. cruzi infection we need better programs to screen pregnant women and their infants. We also need screening and treatment programs for children and young adults.…”

“…Reply to Henao-Martínez, et al TO THE EDITOR-Because of the natural history of Trypanosoma cruzi infection as well as their vector exposure history, it is highly unlikely that the women in our study [1] were in the acute phase of infection, as suggested by Henao-Martínez [2]. The acute phase begins 1-2 weeks after vector-borne parasite exposure and lasts 4-8 weeks.…”

“…Moreover, the prevalence of reported domestic infestation at the time of study was even lower for women who transmitted infection to their infants than for those who did not (12.9% vs 23.4%, respectively), the reverse of the relationship expected if acute phase infection were responsible for the higher parasitemia levels in transmitting mothers [1]. The parasite loads in women who transmitted infection, while higher than in nonpregnant adults with chronic T. cruzi infection, were substantially lower than those seen in the acute phase (eg, in congenitally infected infants) or in patients with human immunodeficiency virus (HIV) coinfection and T. cruzi reactivation [4,5].…”

Toward Improving Early Diagnosis of Congenital Chagas Disease in an Endemic Setting

“…With the marked decline in vector-borne transmission, congenital infections are now estimated to account for 22% of new cases [1]. The Bolivian Gran Chaco region has the highest Trypanosoma cruzi seroprevalence in the world; the majority of adults are infected, including 20-50% of women of child-bearing age [2]. Women infected as children remain at risk of vertical transmission throughout their child-bearing years, and congenitally-infected women can transmit to their children, thus sustaining the cycle across generations in the absence of the vector [3].…”

“…We conducted a cohort study of pregnant women and their infants in two hospitals in Bolivia from 2010 to 2014 [2]. The objectives of the current analysis were to evaluate the performance of diagnostic tests applicable early in infancy and to describe the clinical manifestations of congenital Chagas disease in an endemic setting.…”