PLASMODIUM-VIVAX - DETECTION OF BLOOD PARASITES USING FLUOROCHROME LABELED MONOCLONAL-ANTIBODIES

A monoclonal antibody (MoAb) 2C6111 specific for Plasmodium vivax eryt hrocytic stages was shown to detect parasitized erythrocytes in blood samples collected in the field. This MoAb binds to the mature trophozo ite, schizont and gametes of P. vivax and upon examination of 43 wild isolates no evidence of polymorphism was found. To search for P. vivax parasites in human blood a MoAb immunofluorescent test (MoAb-IFT) was developed. The assay, is based on the ability of fluorescein isothioc yanate labelled MoAb 2C6111 to combine with parasitized erythrocytes o n thin blood smears. A preliminary field trial was carried out in Vene zuela to determine the usefulness of MoAb-IFT for the specific diagnos is of P. vivax malaria. Blood samples collected from malarious and non -malarious individuals were examined both by standard microscopy of Gi emsa stained thick blood smears (G-TS) and MoAb-IFT. The latter was sp ecific and gave a 100% correlation with G-TS. Sensitivity was close to that usually achieved with Giemsa stained bloodfilms.