AIM:To study the clinical and epidemiological features ofpatients with clonorchiasis so as to provide scientificevidences for the diagnosis and prevention of clonorchiasis.METHODS:Stools from 282 subjects suspected of havingclonorchiasis were examined for helminth eggs with modifiedKato’s thick smear and sedimentation methods,and theirsera were tested for HAV-DNA,HBV-DNA,HCV-RNA,HDV-RNA and HEV-RNA with polymerase chain reaction (PCR).Clinical symptoms of patients with clonorchiasis only wereanalyzed,and their blood samples were tested for circulatingantigen (CAg) with Dot-ELISA,esoinophilic granulocyte count,and alanine aminotransferase (ALT).Meanwhile,they wereasked to provide data of occupation,eating habit,hygienichabit and knowledge of donorchiasis.In addition,the ecosystemof the environment in epidemic areas was surveyed.RESULTS:Among the 282 patients,61 (21.43%) wereinfected with clonorchis sinensis only,97 (34.64%) wereco-infected with clonorchis sinensis and other pathogens,92 (32.86%) were infected with hepatitis virus only and 31(11.07%) neither with clonorchis sinensis nor hepatitis virus.Among the 61 patients with clonorchiasis only,there were14 (22.95%) subjects with discomfort over hepatic region orepigasfrium,12 (19.67%) with general malaise or discomfortand inertia in total body,6 (9.84%) with anorexia,indigestionand nausea,4 (6.56%) with fever,dizziness and headache(6.56%),and 25 (40.98%) without any symptoms;sixty one(100%) with CAg (+),98.33% (59160) with eosinophilicgranulocytes increased and 65.00% (39/60) with ALTincreased.B-mode ultrasonography revealed 61 cases withdilated and thickened walls of intrahepatic bile duct,andblurred patchy echo acoustic image in liver.Twenty-six caseshad stones in the bile duct,39 cases had slightly enlargedliver with diffuse coarse spots in liver parenchyma.Twentycases had enlarged gallbladder with thickened coarse walland image of floating plagues,9 cases had slightly enlargedspleen.By analysis of epidemiological data,we found thatthe ecologic environment was favorable for the epidemiologyof clonorchiasis.Most patients with clonorchiasis were lack ofknowledge about the disease.Their living environment,hygienic habits,eating habits and their occupations werethe related factors that caused the prevalence of the disease.CONCLUSION:The clinical symptoms of clonorchiasis arenon-specific,and the main evidences for diagnosis ofclonorchiasis should be provided by etiologic examination, B-mode ultrasonography and clinical history.The infectionof clonorchis sinensis is related to occupations,bad eatinghabits and lack of knowledge about prevention of the disease. AIM: To study the clinical and epidemiological features of patients with clonorchiasis so as to provide scientificevidences for the diagnosis and prevention of clonorchiasis. METHODS: Stools from 282 subjects suspected of having clonorchiasis were examined for helminth eggs with modified Kato’s thick smear and sedimentation methods, and theirsera were tested for HAV-DNA, HBV-DNA, HCV-RNA, HDV-RNA and HEV-RNA with polymerase chain reaction (PCR). Clinical symptoms of patients with clonorchiasis were onlyalyzed, and their blood samples were tested for circulating antigen (CAg) with Dot-ELISA, esoinophilic granulocyte count, and alanine aminotransferase (ALT). Meanwhile, they were made to provide data of occupation, eating habit, hygienichabit and knowledge of donorchiasis. Addition, the ecosystem of the environment in epidemic areas was surveyed .RESULTS: Among the 282 patients, 61 (21.43%) were ingested with clonorchis sinensis only, 97 (34.64%) were co-infected with clonorchis sinensis and other pathogens, 92 (32.86%) were infected with hepatitis virus only and 31 (11.07%) neither with clonorchis sinensis nor hepatitis virus. Amd the 61 patients with clonorchiasis only, there were 14 (22.95%) subjects with discomfort over hepatic region orepigasfrium, 12 (19.67% with general malaise or discomfort and inertia in total body, 6 (9.84%) with anorexia, indigestion and nausea, 4 (6.56%) with fever, dizziness and headache (6.56%), and 25 (40.98%) without any symptoms; (100%) with CAg (+), 98.33% (59160) with eosinophilic granranulocytes increased and 65.00% (39/60) with ALTincreased.B-mode ultrasonography revealed 61 cases withdilated and thickened walls of intrahepatic bile duct, andblurred patchy echoacoustic image in liver.Twenty-six caseshad stones in the bile duct, 39 cases had slightly enlargedliver with diffuse coarse spots in liver parenchyma.Twentycases had enlarged gallbladder with thickened coarse walland image of floating plagues, 9 cases had slightly enlargeddspleen.By analysis of epidemiologmedical data, we found that the ecologic environment was favorable for the epidemiology of clonorchiasis. Patients with clonorchiasis were lack of knowledge about the disease. living conditions, hygienic habits, eating habits and their occupations were the related factors that caused the prevalence of the disease .CONCLUSION : The clinical symptoms of clonorchiasis are non-specific, and the main evidences for diagnosis of clonorchiasis should be provided by etiologic examination, B-mode ultrasonography and clinical history. The infection of clonorchis sinensis is related to occupations, bad eatinghabits and lack of knowledge about prevention of the disease.