Longitudinal observation on the prevalence and variation of human Clonorchiasis infection in 14 counties in Guangxi

Objective To investigate longitudinally the prevalence of Clonorchiasis in Guangx. Methods Two surveys were carried out in the year of 1989 and 2002.The sites and counties of survey were selected by stratified sampling considering geography and economy levels and totally 14 counties were sampled. The Kato-Katz thick smear was used for fecal examining. Eggs per gram of feces (EPG) of Clonorchis sinensis were counted. Results Totally 36 304 stool samples were examined in the first survey ( 1989 ) and 21 644 stool samples in the second (2002). The prevalence in the second survey was 5.16%(1 116/21 644), which was 3.17 times of that of the first 1.63%(592/36 304). There a 3.66 and a 2.8 folds sharply increase in the infection of females and males were observed. The Comparatively, The highest rise of 5.88 times in infection in preschool children was noticed . On the basis of EPG, the rate of Light infection decreased from 73.14% in 1989 to 55.91% in 2002,while the rates of the moderate, heavy and super-heavy infection were increased by 34.32%, 6.01% and 3.76% respectively. Conclusion The prevalent trend of C. sinensis in Guangxi Zhuang Autonomous Region is increasing, indicating that more intensified control strategies should be made.