Potential value of Plasmodium falciparum-associated antigen and antibody detection for screening of blood donors to prevent transfusion-transmitted malaria.
BACKGROUND
Malaria antibody detection is a valuable tool in the prevention of transfusion-transmitted malaria in countries with a high proportion of donors with travel exposure to malaria. The immunofluorescent antibody test (IFAT) is still the reference method, but it is not suitable for screening of blood donors. ELISA would be an interesting alternative to the IFAT, but it lacks sensitivity.


METHODS
To evaluate the potential value of a combined screening strategy based on malaria antigen and antibody detection, plasma samples from 203 patients infected with Plasmodium falciparum were tested with an ELISA for the detection of malaria antibodies (Malaria IgG CELISA, Cellabs) and a P. falciparum histidine-rich protein-2 kit (Malaria P.f., ICT Diagnostics) for the detection of malaria antigens.


RESULTS
Among patients with positive IFAT results, CELISA had a sensitivity of 71 percent, whereas the combined screening tests (CELISA and Malaria P.f.) had a sensitivity of 88 percent (p < 0.001). Sequential samples from 50 patients were tested. The combined screening tests shortened the detection of seroconversion from 11.4 +/- 1.6 to 5.3 +/- 1.1 days (p < 0.001).


CONCLUSIONS
Combined malaria antigen and antibody detection, with methods compatible with mass screening, may constitute an attractive alternative to the IFAT for blood donor screening.
Silvie
Olivier
O
INSERM (National Institute for Health and Medical Research) Unit 511, Cellular and Molecular Immunobiology of Parasitic Infections, Hospital University Center, Pitié-Salpêtrière, Paris, France. silvie@ext.jussieu.fr
Thellier
Marc
M
Rosenheim
Michel
M
Datry
Annick
A
Lavigne
Patricia
P
Danis
Martin
M
Mazier
Dominique
D
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000097:blood*; D001782:Blood Donors; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000517:prevention & control* / Q000635:transmission*; D010963:Plasmodium falciparum / Q000276:immunology*; D012680:Sensitivity and Specificity
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G