Epidemiology and control of clonorchiasis in Korea.

several riversides in order to investigate the actual status of C. sinensis infection among reverside inhabitants. The survey results showed an overall infection rate of 21.5%: An infection rate of 40.2% in the Nakdong River basin ranked first, 30.8% in the Yeongsan River basin second, 17.3% in the Seomjin River basin third, 15.9% in the Tamjin River basin fourth, 15.7% in the South Han River basin fifth, 12.0% in the Kum River basin sixth and 8.0% in the Mangyong River basin last. They estimated the number of people infected with C. sinensis at approximately 830,000 to 890,000 of the total 4 million inhabitants of the above 7 basins. According to Song et al (1983), generally inhabitants living along riversides showed relatively high rates whereas those living in regions not connected with the rivers or in places near the seashore rarely showed C. sinensis eggs. However in certain areas which is not directly drained by the rivers, the inhabitants showed rather high rates of infection.