title: Prevalence of Trypanosoma cruzi infection in blood donors in El Salvador between 2001 and 2011.
abstract: BACKGROUND
  El Salvador is regarded as a highly endemic country for Chagas disease, as evidenced by the relatively high estimated positive serology rate for Trypanosoma cruzi among blood donors. This study aimed to identify the factors contributing to this high rate by analyzing changes in T. cruzi seroprevalence.
  
  
  METHODS
  Secondary data were collected from 31 blood banks operated by the Ministry of Health, the Red Cross, the Institute of Salvadoran Social Security, and the Military Hospital. The data were analyzed to determine the number of cases of T. cruzi seropositivity, and the average prevalence of seropositivity by province. Simple linear regression was performed to identify trends in T. cruzi seropositivity.
  
  
  RESULTS
  Analysis of the 885,187 blood samples collected between 2001 and 2011 revealed 21,693 cases of transfusion-related infections, with a significant reduction of T. cruzi seropositivity from 3.7% in 2001 to 1.7% in 2011, reflecting a 54% decrease over the course of a decade (R(2) = 89.6%, p > 0.001). T. cruzi seroprevalence decreased in San Salvador, Santa Ana, Sonsonate, and Cuscatlán. In contrast, seroprevalence remained high with no decrease in Ahuachapán and San Vicente, and consistently low in the remainder of the country.
  
  
  CONCLUSIONS
  Although the national prevalence of T. cruzi among blood donors has decreased, it remains high in the provinces of Ahuachapán and San Vicente. Strengthening vector control activities and developing an approach for the systematic follow-up of prospective blood donors with positive serology for T. cruzi are required, especially in areas with high seropositivity.
authors.affiliation: School of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. ebodo77@yahoo.co.jp.
authors.forename: Emi
authors.initials: E
authors.lastname: Sasagawa
authors.forename: Ana Vilma
authors.initials: AV
authors.lastname: Guevara de Aguilar
authors.forename: Marta Alicia
authors.initials: MA
authors.lastname: Hernández de Ramírez
authors.forename: José Eduardo
authors.initials: JE
authors.lastname: Romero Chévez
authors.forename: Jun
authors.initials: J
authors.lastname: Nakagawa
authors.forename: Rafael Antonio
authors.initials: RA
authors.lastname: Cedillos
authors.forename: Chizuru
authors.initials: C
authors.lastname: Misago
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001782:Blood Donors; D014355:Chagas Disease / Q000453:epidemiology* / Q000469:parasitology; D004544:El Salvador / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016036:Seroepidemiologic Studies; D014349:Trypanosoma cruzi / Q000302:isolation & purification*; D055815:Young Adult