ABSTRACT
A total of 618 sera from inhabitants living in various endemic areas in Indonesia were examined for IgG against Plasmodium falciparum utilizing young trophozoites and mature schizonts as antigens by the method of ELISA and IFAT. In general, antibodies against trophozites (RESA) based on ELISA and antibodies against schizonts based on IFAT showed a correlation of malarial antibodies with the level of endemicity of the area examined. Anti-RESA antibody, detected either by ELISA or IFAT was more pronounced in the aparasitemic group compared to the parasitemic group. On the contrary, anti-schizont antibody measured by IFAT was more pronounced in the parasitemic group. Malarial antibody levels against the schizont-merozoite fraction of P. falciparum as assayed by ELISA appeared to develop more slowly compared to levels based on IFAT.