Antibody detection ELISAS for malaria diagnosis.

Parasite extracts of Plasmodium falciparum and P. chabaudi and three synthetic peptides from the P. falciparum MSA2 merozoite antigen were tested for suitability as antigens in an antibody detection ELISA using sera from malaria patients in Brisbane. The P. chabaudi extract was superior to P. falciparum extract for detecting P. vivax cases, while for P. falciparum cases the two parasite extracts were equivalent. Single peptide antigens were generally less sensitive than parasite extracts; however, peptides G3 and G7 were more sensitive than parasite extracts in detecting first attacks of P. vivax. Examination of isotype specific responses demonstrated that this may be explained by higher IgG responses to these peptides in first than in subsequent P. vivax attacks