DEVELOPMENT OF AN IMMUNOENZYMATIC ASSAY USING A MONOCLONAL-ANTIBODY AGAINST A 50-KDA CATABOLITE FROM THE P126 PLASMODIUM-FALCIPARUM PROTEINTO THE DIAGNOSIS OF MALARIA INFECTION

The WHO criterion of deferring any donation of blood by a confirmed ca se of malaria for three years after cessation of therapy can not be ap plied in areas where malaria is endemic. For this reason we developed an immunoenzymatic assay for the detection of plasmodial antigens for blood screening in malarial endemic areas. So, we tested sera from 191 individuals. Among patients with active disease 100% of the cases of Plasmodium falciparum or mixed infections and 91.7% of those with P. v ivax were positive for the presence of plasmodial antigens. The lower parasitaemia detected was 0.0003% for P. falciparum and 0.001% for P. vivax malaria. When the frequency of positive circulating malarial ant igens was evaluated among asymptomatic and symptomatic individuals wit h negative TBS, positive results were found in respectively 38.7% and 17.7% of the individuals studied in the 30 days after confirmed malari a attack. Data provide by these assays have shown that ELISA seemed to be more sensitive than parasitological examination for malaria diagno sis. This test by virtue of its high sensitivity and the facilities in processing a large number of specimens, can prove to be useful in end emic areas for the recognition of asymptomatic malaria and screening o f blood donors.