Status of Plasmodium vivax malaria in the Republic of Korea during 2001-2003.

The Republic of Korea experienced a re-emergence of Plasmodium vivax malaria in 1993. The incidence of this disease increased rapidly through 2000 with its geographic distribution expanding from the vicinity near the Demilitarized Zone to the adjacent outlying areas. However, the number of cases of P. vivax malaria since that time period has decreased. A total of 2,538 cases occurred in 2001, and this decreased to 1,761 cases and 1,164 cases in the two subsequent years. A total of 5,463 cases of P. vivax malaria were reported from 2001 through 2003; 25.26% (1,380) were reported among Republic of Korea military personnel, 27.48% (1,501) were among veterans who had been discharged from the military within two years, and 47.26% (2,582) were among the civilian population. Mosquito control activities by the North Korean and South Korean governments, chemoprophylaxis of Republic of Korea Army personnel, and the low level of Anopheles mosquitoes in 2001 may have been factors responsible for the decreasing number of malaria cases. However, local transmission might have taken place in urban regions of the malaria-risk areas that are within 30 km south of the Demilitarized Zone. Extensive intervention and continued surveillance are warranted to prevent the epidemic from re-expanding and to eliminate this disease in the Republic of Korea.