Objective To explore the suitable chemotherapy measures in different Clonorchis sinensis infectiosity endemic ar-eas. Methods The interventional groups and control groups were set up in the heavy,moderate and light C. sinensis infectiosity areas in Guangdong Province,respectively. In the intervention groups,the chemotherapy was administered among all the residents aged above 3 years in the heavy endemic areas,the chemotherapy was given among the focus populations in the moderate endemic areas,and the chemotherapy was administered among the residents infected with C. sinensis confirmed by stool examinations in the light endemic areas. No measures were carried out in the control groups. Results One year after the interventions,the C. sinensis infection rates of the interventional groups decreased by 47.90%,86.52%and 100%,the abnormal rates of liver B ultrasonic ex-aminations decreased by 26.50%,31.00%and 100%,the ALT abnormal rates decreased by 48.70%,62.30%and 100%,and the AST abnormal rates decreased by 55.50%,39.90% and 100% in the heavy,moderate and light endemic areas,respectively. There was no decreasing trend of above-mentioned indexes in the control groups. Conclusion In the different C. sinensis infectios-ity endemic areas,the different chemotherapy measures should be carried out.

Objective To analyze the epidemic status of principal human parasites, so as to provide scientific evidence for making prevention countermeasures for Guangdong Province in the future. Methods In 2015, a survey was performed according to the scheme of "The 3rd National Survey of Principal Human Parasites"as well as the incidence of parasites disease in Guangdong Province,the residents at 48 investiation sites in counties were surveyed. The survey of the soil-transmitted nematodes (Ascariasis, Ancylostoma, Trichuris trichiura and Enterobius vermicularis) and intestinal protozoa were performed based on the ecological regions and stratified by economic and geographic situation.The survey of food borne Clonorchis sinensis was performed along with the soil-transmitted nematodes in rural areas, and it was performed by the sample method of random cluster in cities and towns.The residents in each investigation site as the object, the ovum of the soil-transmitted nematodes, Clonorchis sinensis and other helminths were examed by the modified Kato-Katz method, test tube filter paper was used to identify Hookwormspecies, and the intestinal protozoa was checked by direct smear method. The transparent tape anal swabs method for children aged 3 - 6 years to check Enterobius vermicularis. Results Totally 12 401 residents of 48 survey sites from 22 counties were surveyed, and the total infection rate of intestinal parasites was 8.29%(1 028/12 401). The infection rate of soil-transmitted nematodes was 3.39% (420/12 401),in which the infection rate of Ascariasis, Ancylostoma, Trichuris trichiura and Enterobius vermicularis were 0.52% (64/12 401), 1.89%(234/12 401),0.46%(57/12 401),and 0.52%(65/12 401),respectively.The infection rate of Clonorchis sinensis was 4.90%(608/12 401). Nine hundred and sixty-seven children were tested for eggs of Enterobius vermicularis with the infection rate of 12.41% (120/967). The number of hook larva culture was 153, among them, 140 were hookworm larvae of America and no duodenal hookworm larvae and other nematode species were found.Totally 9 309 residents were tested for intestinal protozoa infection,and the infection rate was 0.31%(29/9 309). Conclusion In Guangdong Province, the infection rate of soil-transmitted nematodes is decreasing while the infection rate of Clonorchis sinensis is still high, and the control work of parasites still should be strengthened especially for food borne parasitic diseases.