Surveillance of Clonorchiasis Sinensis in Tongnan County in 2006

Objective To analyze the epidemiology of clonorchiasis sinensis and provide basis for the prevention and control programs.Method 300 stool specimens of the population of age over 5 years were collected in the village.The eggs of Clonorchis sinensis were examined by method of sedimentation and formalin-ether sedimentation technique.The infected and control people were matched according the proportion of 1∶4.The common local fish were collected in the village.The muscle was obtained from the fin,cheek,tail of the collected fish.The metacercaria was examined in the muscle by the microscope.The effect of health education was investigated.Result 12 of 367 people were infected,with an infection rate of 3.27%.There was no significant difference of the infection rate between male and female(P 0.05).The infected individuals were all farmer.The youngest was 32 and the oldest was 73 years old.There were 12 persons in the infected group and 48 persons in the control group.There was no significant difference of the infection rate between the people eating raw fish,half cooked fish,BBQ fish,or fish fed with faeces.12 Clonorchis sinensis metacercariae were found in 131 fish of 4 kinds of fresh water fish and the metacercariae rate was 9.16%.The metacercariae was found in the Pseudorasbora parva and Hemiculter leucisulus.The metacercariae rate of Pseudorasbora parva(25.00%)was higher than Hemiculter leucisulus(P0.05).The rate of knowledge about clonorchiasis sinensis of students was 26.09% and that of villagers was 44.61% before attending health education.The rate of knowledge about clonorchiasis sinensis of students was 84.06% and that of villagers was 98.28% after attending health education.There was significant difference between the two groups in the rate of knowledge about the disease before and after attending health education(P0.01).Conclusion After many years of controlling clonorchiasis sinensis,the infection rate was low.But the area having Clonorchis sinensis is not reduced and the rate of infection still needs to be reduced.The prevention and control program of the disease have to be continued.