Health officials declared Jindo, South Jeolla Province, the country’s first “cancer cluster” on Monday as residents showed abnormally high rates of liver cancer.

A cancer cluster refers to a specific geographic area that has a greater-than-expected number of cancer cases.

By conducting an in-depth epidemiological investigation last year, the Korea Centers for Disease Control and Prevention identified the island as an area of increased liver cancer risk. Health officials also found that hepatitis C was the major cause of the disease, said Rep. Kim Yong-ik of the opposition Democratic United Party at a parliamentary audit session.

According to the report, the rate of liver cancer in Jindo from the year 1999 to 2008 was 40-60 percent higher than the average of other areas in Jeolla Province.

Particularly from 1999 to 2003, about 91.6 in every 100,000 male residents in Jindo were diagnosed with liver cancer, 53 percent higher than the average of other areas in Jeolla Province. About 19 in every 100,000 female residents on the island were diagnosed with liver cancer, much higher than the neighboring communities.

The death rate among patients from liver cancer in Jindo was 60 percent higher than the average during the same period of time, officials added.

The health officials said hepatitis C has been causing liver cancer in the area.

The percentage of people exposed to the hepatitis C virus was five to 10 times higher than in other South Jeolla Province communities, they said.

“Chances are high that hepatitis C has caused many liver cancer cases in Jindo. We are conducting additional investigations to figure out possible routes of the hepatitis C transmission and the rate of hepatitis in the region,” an official at KCDC said.

Hepatitis C is believed to be transmitted only by blood and body fluid when people share needles or other equipment to inject drugs. Hepatitis C can be transmitted during sexual contact with a person infected or being born to a mother who has the virus, officials warned.

The disease control agency plans next year to test about 2,000 middle- and high-school students in the area to study how far the virus has been transmitted.

By Cho Chung-un (christory@heraldcorp.com)