Evaluation of a malarial antibody assay for use in the screening of blood and tissue products for clinical use.

BACKGROUND AND OBJECTIVES: A new recombinant Plasmodium antigen enzyme immunoassay (EIA) for the detection of malarial antibodies was evaluated for the screening of 'malaria-risk' blood and tissue donations. MATERIALS AND METHODS: A total of 13,269 donor and patient samples were tested by both the EIA and the standard diagnostic antibody immunofluorescence test (IFAT). RESULTS: A total of 114/138 (82.6%) samples from patients with P. falciparum and 11/13 (84.6%) samples from patients with P. vivax tested positive. A total of 714/13,053 (5.47%) samples from donors identified as 'malaria risk', owing to residency or travel, were reactive in the EIA. CONCLUSIONS: The assay is more sensitive than a previously implemented malarial antibody EIA (73% in acute P. falciparum and 56% in acute P. vivax infections). The sensitivity of this new EIA is comparable to that of the IFAT, and the specificity is sufficient to screen 'malaria-risk' donors.