The status of Clonorchis sinensis infection in Korea: What should be done to eliminate clonorchiasis?

Division of Malaria and Parasitic Diseases, Center for Immunology and Pathology, NIH, CDC Ju Jung-Won, Lee Myoung-Ro, Shin Hee-Eun, Cho Shin-Hyeong

Clonorchis sinensis (Cs), or liver fluke, is a parasite that represents the highest rates of intestinal parasitic diseases in Korea. Chronic Cs infection causes abnormal liver function and induces cholangiocarcinoma. In this report, we introduce the general status and risks of Cs infection and discuss efforts to eliminate it. Human Cs infection was first discovered on September 8, 1874 at the Medical College Hospital in Calcutta, India. Cs is a foodborne parasitic disease. To prevent Cs infection, it is important to change the habit of eating raw fish from freshwater sources. In endemic areas, through intensive control program to eliminate clonorchiasis, the incidence of Cs infection has decreased. The development and application of highly sensitive and specific diagnosis would be needed to control and eliminate clonorchiasis. Praziquantel (PZQ) is the only recommended drug for clonorchiasis treatment. There is a need to develop a better drug with less side effects and less dosage. The prevalence of cholangiocarcinoma is high in Cs endemic areas, while Cs-associated cancer could develop faster and has a shorter survival period. More efforts would be needed to eliminate clonorchiasis that include: 1) development of materials for public awareness campaigns and wide distribution of these in Cs endemic areas; 2) ensuring availability of simple and accurate diagnosis method that can be applied directly in the field; and 3) development of therapeutics that can replace PZQ.