Malaria makes a comeback as mosquitos migrate

An office worker with the family name Kim, 58, from Goyang, Gyeonggi recently sought medical treatment after enduring three weeks of chills and fever, which he initially thought was just a cold. But a blood test revealed that Kim had Plasmodium vivax, more commonly known as tertian malaria or hakjil in Korean.

Kim had not been to Southeast Asia or local areas where the disease-carrying Anopheles mosquitoes commonly live, only traveling to his office in Seoul from his home in Ilsan.

“The frequency of malaria outbreaks among people, regardless of age and gender, is rising across the country, not just in northern Gyeonggi where it was most common,” said Heo Ae-jeong, professor of internal medicine at Ilsan Hospital. “Every year we treat about 50 malaria patients, and some of them have never been outside the city.”

Far from just being annoying, mosquitoes can be carriers of deadly diseases like malaria, Japanese encephalitis, and dengue fever.

Malaria is no longer a threat confined to Africa or Southeast Asia. The female Anopheles mosquito, which spreads tertian malaria, originally inhabited the DMZ area adjacent to North Korea, but has migrated south in recent years.

Tertian malaria is not the deadliest form of the disease, but it is recurring and is the most widespread. This year, 338 people have been afflicted.

After an epidemic in 1970 was stopped, there were fewer than 100 malaria patients by the early 1990s. In 2000, however, there were 4,142. The number briefly decreased to 864 in 2004; in the past two years it has climbed back to 2,000.

The Korea Centers for Disease Control and Prevention have classified 22 cities and districts in Gangwon, Gyeonggi and Incheon as “malaria danger zones,” with 10 out of 1 million people affected annually.

In the past couple of years, the disease that broke out sporadically among soldiers around the DMZ in areas like Yeoncheon and Cheorwon has now moved southward as far as Ganghwa County, Incheon and Ilsan in Gyeonggi Province. This year, Goyang, Gyeonggi, a densely populated residential area, has been added to the list of danger zones.

Kim Jung-yon, a researcher for the malaria parasite team at the Korea Centers for Disease Control and Prevention, said, “The resurgence of the 1910 strain of malaria is a combination of the changing temperature, humidity and environment of the Korean Peninsula. It seems the Anopheles mosquito flew to the South from the North in the late ’90s, and has become native to the land.”

By Kim Eun-ha JoongAng Ilbo [enational@joongang.co.kr]