Current status and the changing pattern of the prevalence of clonorchiasis in the inhabitants in Sanchong-gun, Kyongsangnam-do, Korea

Abstract

This study was conducted to evaluate the current endemicity and the transition mode of the Clonorchis infection in Sanchong-gun Kyongsangnam-do. The areas of investigation, villages and schools surveyed, method and techniques used in this study were the same as in 1984. The egg positive rate of clonorchiasis in the general population of Sanchong-gun was 37.6% out of 837 examined persons. In the schoolchildren, the rate was 9.7% out of 145 persons examined. In the intensity of the infection among the cases, the mean EPG (Egg per gram of feces) in the inhabitants and schoolchildren were 3,310 (male 4,221, female 1,978) and 711 (male 620, female 833), respectively. Of the inhabitants with clonorchiasis, the cases of light infection (EPG < 1,000) and moderate infection (1,000 < EPG < 10,000) were 93.9%. The proportion with experience of eating raw freshwater-fish was 90.5% among the infecteds. Out of 138 inhabitants examined in both 1984 and 1992, the number of the positives by both examinations was 31 (22.5%), positive to negative conversion was 35 (25.4%), negative to positive conversion was 22 (15.9%). The present results reveal that there are no changes of the egg positive rate of clonorchiasis among inhabitants in Sanchong and the eating habit of raw freshwater-fish persists there. In this community, the eating habit is the most important problem to be solved for control of this endemic disease.