Comparative analysis of two epidemiological surveys on infection of Clonorchis sinensis in Guangxi,China

Objective To analyze the current status and transmission trend of human infection of Clonorchis sinensis in Guangxi providing updated information for the development of control measures.Methods Two province-wide surveys on C.sinensis sampled by stratified random sampling method.The fecal examination was conducted by Kato-Katz method and the data were collected by questionnaires on the dwellers.The results of two surveys were compared.Results C.sinensis had been prevalent mainly in residents living in Youjiang River and Yongjiang River valley,and the infection rates increased from 0.08% and 4.66% to 2.44% and 10.22%,respectively.Among the infected,most of them were youth and middle-aged people.It was noted that the ratio of the male and female infected residents decreased from 2.69∶1 to 2.14∶1.The C.sinensis egg positive rates remained higher in cadres,physicians,teachers,businessman,farmers and workers.The proportion of moderate and heavy infections in the total number of infected increased from 26.32% to 40.66%,in particular,the heavy infection increased more significantly. Conclusion Most C.sinensis infection distributed in Youjiang River and Yongjiang River valley,and the prevalence rate of infection has a tendency to rise.The youth and middle-aged people were mostly affected,and the female is at higher risk.Furthermore,the odds of symptomatic cases are found to be on rise.