The Korea Centers for Disease Control and Prevention are asking people to watch out for possible malarial infections.
The number of people infected with the disease marked 1,772 last year, a sharp increase from 1,023 in 2008, the authorities said.
Currently, Ganghwa Island of Incheon is designated as a danger zone, while six regions of Gyeonggi Province, two in Gangwon Province and three in Incheon are designated as malaria watch zones.
The administration advised people to wear long sleeves, refrain from going outdoors after sunset and to always wear mosquito repellent. Those who suffer from an extremely high fever should visit local health centers or doctors.