Abstract：The current situation and the geographic distribution of clonorchiasis in Anhui province were investigated according to "Rules and Regulation for implementation of Nation-Wide Survey of current situation of major Parasitic Diseases in China",in which the stratified cluster random sampling was used based on two characteristic features with water system or landform and degree of prevalence,and the modified Kato-Katz thick smear technique was employed to examine ova of Clonochis sinensis.All together,14 541 persons in 27 points of 10 counties were examined,among which 105 persons were found to be infected with C.sinesis with an average infection rate of 0.722%(male:0.729%','female 0.715%).There were no significant difference in sex(χ2=0.0095,P>0.05).The average EPG was 149,among which the constituent ratio of light infection(EPG<1 000) was 96.97%.Meanwhile the infection rates in Huaihe,Yangtze and Qiangtang river valley were 1.085%,0.173% and 0.064% respectively,As to the landform distribution,the infection rates in proper sequence from high to low were plain strip(1.394%),water net region(0.199%),hilly land(0148%) and mountain area(0.095%) respectively.The highest infection rates in area distribution was in the Huibei plain(1.389%),followed by central hilly area(0.036%),south plain(0.199%) and west,mountain area(0.196%).The lowest infection rate was found in the southern mountain area(0.054%).There was significant difference between Huibei plain and other area(P<0 01).From these observations,it is evident that most cases of clonorchiasis in Anhui province are predominately of light infections.In comparison with the results of the last provincial survey performed in 1990,the infection rate and average EPG of C.sinesis seem to be reduced significantly,however,the Huaihe river valley is still the highest prevalent area of infection with C.sinesis in Anhui province.
