title: Selective testing for Trypanosoma cruzi: the first year after implementation at Canadian Blood Services.
abstract: BACKGROUND
  Various testing strategies may reduce the risk of Chagas disease transmission in nonendemic, low-prevalence countries. Results of the first year of selective testing of at-risk donors at Canadian Blood Services are reported.
  
  
  METHODS
  Since February 2009, platelets were not produced from at-risk donors. Since May 2010, at-risk donors were tested for Trypanosoma cruzi antibodies. Donors testing positive were interviewed about risk factors, and lookback studies were initiated.
  
  
  RESULTS
  There were 7255 at-risk donors of 421,979 donors screened (1.72%). Risk factors were born in Latin America (50.6%), mother or maternal grandmother born in Latin America (28%), and 6 months or more travel history or residence in Latin America (19%). Sixteen (16) at-risk donors had T. cruzi repeat-reactive test results of whom 13 confirmed positive. Eleven of 13 were born in Latin America (nine in Paraguay and two in Argentina), and the other two were born in Canada but had short-term travel history and mothers who had been born in Latin America. Ten of the donors spoke German as their first language (all of those born in Paraguay and one born in Canada). There were 148 previous donations (176 components transfused) evaluated by lookback, of which 28% of recipients could be tested. None were positive.
  
  
  CONCLUSIONS
  Selective testing has mitigated a small risk to the blood supply with very few false-positive results. Most positive donors were born in a risk country, with a concentration of German-speaking immigrants from Paraguay. Residency or travel alone were not clear risk factors.
authors.affiliation: Canadian Blood Services, Ottawa, Ontario, Canada. sheila.o'brien@blood.ca
authors.forename: Sheila F
authors.initials: SF
authors.lastname: O'Brien
authors.forename: Vito
authors.initials: V
authors.lastname: Scalia
authors.forename: Mindy
authors.initials: M
authors.lastname: Goldman
authors.forename: Wenli
authors.initials: W
authors.lastname: Fan
authors.forename: Qi-Long
authors.initials: QL
authors.lastname: Yi
authors.forename: Irene R
authors.initials: IR
authors.lastname: Dines
authors.forename: Mary
authors.initials: M
authors.lastname: Huang
authors.forename: Momar
authors.initials: M
authors.lastname: Ndao
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Fearon
mesh_terms: D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001782:Blood Donors; D058731:Blood Safety / Q000379:methods*; D002170:Canada; D014355:Chagas Disease / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology / Q000209:etiology; D046148:Donor Selection / Q000379:methods*; D006801:Humans; D007843:Latin America / Q000208:ethnology; D008875:Middle Aged; D015397:Program Evaluation; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014349:Trypanosoma cruzi / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D015415:Biomarkers