Eight volunteers test positive for dengue fever

Eight volunteers in a group who recently returned from Sri Lanka have been diagnosed with dengue fever, local health authorities announced on Thursday.

Among the group of 35, six initially tested positive for the virus, while two others who later showed similar symptoms were confirmed Thursday by the National Research Institute of Health to be infected with the disease, officials from the Centers for Disease Control and Prevention (CDC) said.

The two had previously tested positive in medical tests performed in Sri Lanka.

The patients were part of a volunteer group of students, professors and faculty members from Keimyung University, based in Daegu, who visited the South Asian nation on Dec. 23.

The six people initially confirmed to have dengue fever left early on Dec. 31, while the rest remained in Sri Lanka until Monday, when two more members were believed to have been affected.

The group is currently being monitored by local health officials.

According to the CDC, this is the first time in Korea that dengue fever has been detected in a traveling group. The mosquito-borne tropical disease is usually brought in by people who are infected outside the country, with some 100 to 200 cases reported each year.

Dengue viruses are transmitted to humans through bites from female mosquitoes carrying the disease; the Aedes aegypti mosquito is the primary vector of dengue, according to the World Health Organization (WHO). The mosquito originated in Africa and spread to tropical and subtropical regions in Asia, with Korea as an exception. The CDC emphasized in a statement that the virus cannot be transmitted person-to-person.

According to the WHO, there is no specific treatment or vaccine for dengue fever, but early detection and access to proper medical care lowers fatality rates to below 1 percent.

The infection, also known as breakbone fever, causes flu-like symptoms, and occasionally develops into a potentially lethal complication called severe dengue, which often manifests in children.

Of the estimated 500,000 people who are diagnosed with severe dengue worldwide each year, about 2.5 percent die, data compiled by the WHO show. Symptoms include high fever, headache, muscle and joint pain, nausea and vomiting. The incubation period is between four and 10 days after a bite from an infected mosquito.

BY LEE SUNG-EUN [lee.sungeun@joongang.co.kr]