Abstract. Malaria had been eradicated in the Republic of Korea (South Korea) by the late 1970s. In 1993, a soldier was infected with Plasmodium vivax malaria in the Demilitarized Zone (DMZ; the border area between North and South Korea), and since then, the number of cases has been steadily increasing year after year. In 1998, 3,932 vivax malaria cases were microscopically confirmed, affecting 2,784 (70.8%) soldiers (including discharged soldiers) and 1,148 (29.2%) civilians. These cases occurred throughout the year, peaking in July (30.1%) and August (30.5%). Most of the patients were infected in areas in or near the DMZ. Taking into consideration entomologic, socioecologic, and epidemiologic factors, it is postulated that there has been an epidemic of malaria in North Korea since 1993, with the number of cases increasing yearly; the continuous infiltration across the DMZ from North Korea of infected female mosquitoes of the vector species Anopheles sinensis resulted in an outbreak of vivax malaria in the DMZ of South Korea.

An epidemiological study was performed to know the recent infection status of Paragonimus westermani metacercariae (PwMc) in freshwater crayfish, Cambaroides similis, from 2 streams in Jeollanam-do, Republic of Korea. Crayfish were collected from creeks in Bogil-do (Island), Wando-gun, and in a creek near Daeheung Temple in Haenam-gun. The infection rate of crayfish with PwMc in Bogil-do was 89.8%, and the metacercarial burden was 37 PwMc per the infected crayfish. Crayfish in a creek near Daeheung Temple were larger and twice heavier than those in Bogil-do. Of them, 96.5% were infected with PwMc. An average of 140 metacercariae was found in the infected crayfish, almost quadruple to those of Bogil-do. There was a strong correlation between the number of PwMc and body weight of the crayfish. These results suggest that P. westermani metacercariae are still prevalent in crayfish of the 2 regions in Jeollanam-do, Korea.