The duration of infection, frequency of eating raw fresh water fishes, and a series of liver function tests were studied in a group of 23 Korean symptomless cases with Clonorchis sinensis, and compared with those in a control group of uninfected persons. Of 23 lightly infected cases, 11 cases who had been infected for 10 to 20 years was found the highest in percentage(47.8), and 2 had been infected for over 30 years. The frequency of eating raw fresh water fishes ranged from 2 to 35 times. The range of Stoll egg-counts in 23 cases varied from 600 to 8,600 eggs per gram of feces and the average value was approximately 2,800 eggs. A series of liver function tests examined showed normal value in all cases. These results showed no difference in either infected group and its contol group.
