title: Sustained Domestic Vector Exposure Is Associated With Increased Chagas Cardiomyopathy Risk but Decreased Parasitemia and Congenital Transmission Risk Among Young Women in Bolivia.
abstract: BACKGROUND
  We studied women and their infants to evaluate risk factors for congenital transmission and cardiomyopathy in Trypanosoma cruzi-infected women.
  
  
  METHODS
  Women provided data and blood for serology and quantitative polymerase chain reaction (PCR). Infants of infected women had blood tested at 0 and 1 month by microscopy, PCR and immunoblot, and serology at 6 and 9 months. Women underwent electrocardiography (ECG).
  
  
  RESULTS
  Of 1696 women, 456 (26.9%) were infected; 31 (6.8%) transmitted T. cruzi to their infants. Women who transmitted had higher parasite loads than those who did not (median, 62.0 [interquartile range {IQR}, 25.8-204.8] vs 0.05 [IQR, 0-29.6]; P < .0001). Transmission was higher in twin than in singleton births (27.3% vs 6.4%; P = .04). Women who had not lived in infested houses transmitted more frequently (9.7% vs 4.6%; P = .04), were more likely to have positive results by PCR (65.5% vs 33.9%; P < .001), and had higher parasite loads than those who had lived in infested houses (median, 25.8 [IQR, 0-64.1] vs 0 [IQR, 0-12.3]; P < .001). Of 302 infected women, 28 (9.3%) had ECG abnormalities consistent with Chagas cardiomyopathy; risk was higher for older women (odds ratio [OR], 1.06 [95% confidence interval {CI}, 1.01-1.12] per year) and those with vector exposure (OR, 3.7 [95% CI, 1.4-10.2]). We observed a strong dose-response relationship between ECG abnormalities and reported years of living in an infested house.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Cardiology, Children's Hospital of Philadelphia, Pennsylvania.
authors.forename: Michelle
authors.initials: M
authors.lastname: Kaplinski
authors.affiliation: Division of Internal Medicine, Brown University, Providence, Rhode Island.
authors.forename: Malasa
authors.initials: M
authors.lastname: Jois
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland Universidad Católica Boliviana, Santa Cruz, Plurinational State of Bolivia.
authors.forename: Gerson
authors.initials: G
authors.lastname: Galdos-Cardenas
authors.affiliation: Duke Global Health Institute, Duke University, Durham, North Carolina.
authors.forename: Victoria R
authors.initials: VR
authors.lastname: Rendell
authors.affiliation: Saint Louis University School of Medicine, Missouri.
authors.forename: Vishal
authors.initials: V
authors.lastname: Shah
authors.affiliation: Department of Cardiology, University of Colorado, Denver.
authors.forename: Rose Q
authors.initials: RQ
authors.lastname: Do
authors.affiliation: Department of Cardiology, Washington Hospital Center, Washington, District of Columbia.
authors.forename: Rachel
authors.initials: R
authors.lastname: Marcus
authors.affiliation: Department of Cardiology, Duke University, Durham, North Carolina.
authors.forename: Melissa S Burroughs
authors.initials: MS
authors.lastname: Pena
authors.affiliation: Hospital Japonés, Santa Cruz.
authors.forename: Maria del Carmen
authors.initials: Mdel C
authors.lastname: Abastoflor
authors.affiliation: Hospital Japonés, Santa Cruz.
authors.forename: Carlos
authors.initials: C
authors.lastname: LaFuente
authors.affiliation: Camiri Municipal Hospital, Camiri, Plurinational State of Bolivia.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Bozo
authors.affiliation: Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: Edward
authors.initials: E
authors.lastname: Valencia
authors.affiliation: Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: Manuela
authors.initials: M
authors.lastname: Verastegui
authors.affiliation: Universidad Católica Boliviana, Santa Cruz, Plurinational State of Bolivia.
authors.forename: Rony
authors.initials: R
authors.lastname: Colanzi
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Gilman
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco School of Medicine.
authors.forename: Caryn
authors.initials: C
authors.lastname: Bern
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001838:Bolivia; D014355:Chagas Disease / Q000151:congenital / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission*; D016054:DNA, Protozoan / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D007303:Insect Vectors / Q000254:growth & development*; D008875:Middle Aged; D018512:Parasitemia / Q000453:epidemiology* / Q000276:immunology; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D018570:Risk Assessment; D012698:Serologic Tests; D018418:Th2 Cells / Q000276:immunology; D014349:Trypanosoma cruzi / Q000276:immunology / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan
keywords: Chagas disease; Trypanosoma cruzi; cardiomyopathy; infectious disease transmission; vertical