title: Selective Testing of At-Risk Blood Donors for Trypanosoma cruzi and Plasmodium spp. in Switzerland.
abstract: BACKGROUND
  Population migrations and overseas recreational travel to regions at risk for tropical diseases are increasing. A major challenge in non-endemic countries is to decrease the number of blood donor deferrals due those tropical disease pathogens, without compromising the high level of blood safety. The protozoans Trypanosoma cruzi and Plasmodium spp., the causative organisms of Chagas disease (CD) and malaria are becoming a major focus in the blood transfusion community.
  
  
  METHODS
  National guidelines of the Blood Transfusion Service of the Swiss Red Cross propose an algorithm for dealing with these pathogens, including a mandatory selective serological testing of donors at risk.
  
  
  RESULTS
  6,978 donors at risk for CD were tested. Three of them were confirmed anti-T. cruzi -positive, and in one case a transfusion-transmitted infection was highly possible. The specificity of the assay was 99.94%. For malaria 12,887 donors were at risk and 178 were confirmed positive. The specificity of the assays was 92.8%.
  
  
  CONCLUSIONS
  CD and malaria in non-endemic countries may represent a certain risk for blood transfusion. Switzerland chose a selective testing approach. The specificity of the assays is a crucial topic for this approach because it ensures a minimal loss of false-reactive donors and helps towards an easier counselling of implicated donors.
authors.affiliation: Interregional Blood Transfusion Service SRC, Berne, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Niederhauser
authors.affiliation: Blood Transfusion Service SRC Zürich, Schlieren, Switzerland.
authors.forename: Jochen
authors.initials: J
authors.lastname: Gottschalk
authors.affiliation: Interregional Blood Transfusion Service SRC, Berne, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Tinguely
keywords: Chagas; Malaria; Plasmodium spp; Selective testing; Trypanosoma cruzi