For Re-Eradication of Malaria in Korea
By Frank Konings
The Unification Ministry of South Korea has recently announced that it will provide North Korea with $1.18 million worth of supplies this year to help prevent malaria.
Malaria is not a new disease in Korea; in fact, it has had a longstanding presence on the peninsula. Historical records from the Goryeo Kingdom (918-1392) mention malaria outbreaks in the 12th century. Korea was considered malaria-free in 1979, but today, malaria again is a public health concern.
The type of malaria in Korea is vivax malaria, which is acquired through the bite of an infected female mosquito. There are four kinds of human malaria, of which vivax malaria is the most common worldwide and in Asia.
Vivax malaria causes symptoms of recurrent fever and chills, headache, weakness, vomiting and diarrhea. While vivax malaria rarely causes death, its symptoms have a negative social and economic impact.
Drugs are available to prevent or treat the disease, but an effective preventative strategy should also include mosquito control and public education programs.
The National Malaria Eradication Service (NMES) was established in 1959. This collaborative effort between the South Korean government and the World Health Organization (WHO) functioned until 1969.
NMES showed that most malaria cases were in the northern and eastern parts of the country. As a result of NMES's successful strategy and the improving socioeconomic status of South Korea, the number of new malaria cases declined significantly in the 1960s.
The number of malaria cases declined further in the 1970s, most likely as a result of the modernization of farming practices, such as the increased use of pesticides and other chemicals which also kill malaria mosquitoes.
South Korea's efforts to eradicate the disease seemed to work and the country was declared malaria free by WHO in 1979. No new cases of indigenous malaria were identified in South Korea for several years thereafter.
Suddenly, in 1993, a South Korean soldier was diagnosed with vivax malaria. The 23-year-old was stationed at the western edge of the Demilitarized Zone and had never left the country. Malaria was back in South Korea after 14 years of absence.
Over the following years, the number of cases increased annually, reaching a peak of 4,142 cases in 2000. This prompted the South Korean government, in 2001, to start a 10-year program to re-eradicate malaria by 2010.
The latest report from the Korea Center for Disease Control and Prevention shows that, by 2006, the number of annual cases had been cut in half, to 2,021 cases. Now, there are two more years to go before the re-eradication program ends.
North Korea has experienced the same disease trend. Declared malaria free in 1979, there was a reemergence of the disease in the late 1990s. By 1999, the North Korean government reported a total of 100,000 cases, which tripled to 300,000 cases in 2001. Most cases were identified in the southern provinces.
In 1999, the North Korean government and WHO started a national malaria control project, which included the whole spectrum of management strategies: anti-malaria medications, mosquito control and public education.
The project was successful and from 2001 to 2003, there was a steep decline in the incidence of malaria. Recent government figures indicate that the number of cases dropped to 7,436 last year.
Thus, both countries experienced a peak in the number of new cases, most of which occurred near their border, in about 2000. Why did malaria reemerge on the Korean Peninsula? It has been suggested that increased rainfall and floods on the peninsula in the early 1990s created more mosquito breeding places.
In addition, these weather-related events decreased the number of cattle, the preferred source of blood for mosquitoes, which forced mosquitoes to feed on humans. Another hypothesis is that global warming has increased the population of malaria-carrying mosquitoes.
While we wait for scientists to come up with an answer, the border remains no barrier to mosquitoes. Both governments have no other choice than to continue their control programs.
The latest malaria eradication campaigns in South and North Korea have reduced the number of new cases in each country successfully.
But one thing is sure: Because the central part of the peninsula is a malaria hot spot, it is highly unlikely that either country will become malaria free when the other one is not.
Therefore, from a public health point of view, collaboration between the two countries in the fight against malaria should be encouraged, to make the Korean Peninsula, once again, malaria free.
Dr. Frank Konings holds a Ph.D. in microbiology from New York University. He studied malaria in Africa and worked as an epidemiologist at the New York State Department of Health. He currently resides in Seoul and can be reached at fkonings@gmail.com.