title: Evaluation of a malaria antibody ELISA and its value in reducing potential wastage of red cell donations from blood donors exposed to malaria, with a note on a case of transfusion-transmitted malaria.
abstract: OBJECTIVE
  Blood donations are often wasted for lack of a satisfactory procedure to evaluate donors potentially exposed to malaria.
  
  
  METHODS
  We evaluated a commercial ELISA for the detection of antibodies to malaria and compared it with an immunofluorescent antibody test (IFAT).
  
  
  RESULTS
  When 5,311 sera from routine non-exposed donors were tested, 24 (0.45%) were positive by the ELISA, using a Plasmodium falciparum antigen. Seventeen were subjected to confirmatory testing but none were positive by IFAT. Of 1,000 donors potentially exposed in endemic areas 15 (1.5%) were repeatably reactive by ELISA. 10 of these were tested by IFAT and 2 were positive. When 150 patients attending the Hospital for Tropical Diseases in London with acute malaria were tested, 73% of those infected with P. falciparum were repeatably reactive for malarial antibodies by ELISA and 56% with Plasmodium vivax. Of 88 stored clinical sera tested by both IFAT and ELISA 56 were positive by IFAT and of these 52 (93 degrees/0) were positive by ELISA.
  
  
  CONCLUSIONS
  The ELISA is sufficiently sensitive and specific to screen at-risk donors. Its use could safely retrieve 40,000 red cell units currently discarded each year in Great Britain.
authors.affiliation: Hospital for Tropical Diseases, London, UK.
authors.forename: P L
authors.initials: PL
authors.lastname: Chiodini
authors.forename: S
authors.initials: S
authors.lastname: Hartley
authors.forename: P E
authors.initials: PE
authors.lastname: Hewitt
authors.forename: J A
authors.initials: JA
authors.lastname: Barbara
authors.forename: K
authors.initials: K
authors.lastname: Lalloo
authors.forename: J
authors.initials: J
authors.lastname: Bligh
authors.forename: A
authors.initials: A
authors.lastname: Voller
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood*; D001782:Blood Donors; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D017707:Erythrocyte Transfusion / Q000706:statistics & numerical data*; D005069:Evaluation Studies as Topic; D016778:Malaria, Falciparum / Q000276:immunology* / Q000635:transmission; D010963:Plasmodium falciparum / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan