RESUMO
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.
RESUMO
Objecitve To observe the diffusion and distribution of imported Oncomdania snails in non-endemic areas of schistosomiasis.so as to provide scientific basis for developing the scheme of snail surveillance.Methods Oncomelania snails from the msrshland of Dongting Lake were imported in a waste land in March,2008,Qingxin County,which belonged to non-endemic areas of schistosomiasis.and their diffusion and distribution condition were observed from May to December in the same year.Resuits A total of 1 600 Oncomelania snails were imported.The occurrence rate of frame with snails in sunny days and cloudy rainy days were22.88%and 29.24%,respectively,and there was a statistically significant difference between them(χ~2=4.113,P=0.043).Those in waste Land and the sides/bottoms of the ditches were 9.38%and 35.99%,respectively,and the difference between them also showed a statistical significance(χ~2=67.246,P<0.001).The average density of living snails in sunny days and cloudy rainy days were 0.79 and 1.11 No./0.1 m~2,respectively,and those in waste land and the sides/bottoms of the ditches were0.11 and 1.34 No./0.1 m~2.The furthest diffusion distance of snailswas 4.5 m.Conclusions The detective opportunity of imported snails is relatively high in cloudy rainy days,which mainly distribute at the sides/bottoms of ditches and diffuse along the ditches.