Prevalence of antibodies to the circumsporozite protein of Plasmodium vivax in five different regions of Korea.

Malaria has recently re-emerged in the Republic of Korea (ROK), but only few malaria seroprevalences were reported. We obtained 1014 serum samples from inhabitants of five regions of ROK during the high transmission season between June and August in 2001. The levels of anti-circumsporozoite protein (CSP) antibody were assessed in samples using an indirect enzyme-linked immunosorbent assay (ELISA). The highest IgG seroreactivity against Plasmodium vivax recombinant CSP antigen was found among male residents of Cheolwon gun (13.5%), then Incheon (4.7%). The IgG seroreactivity from other regions ranged from 0.0% to 2.0%. These epidemiological data of seroprevalence in five regions of Korea showed a similar pattern to the annual incidence of malaria in these respective regions. The prevalence of antibodies increased with age, suggesting that the age and area-related prevalence patterns reflected differences in the inoculation rates between age groups and geographic regions. Seroprevalence and annual incidence were positively correlated in some areas of Korea.