Study on the health status and affecting factors among people living in the surveillance sites of Three Gorges Reservoir Areas. in 2007 / 中华流行病学杂志

Objective To understand the health status and potential impact resulted in the second stage of Three Gorges Reservoir Areas sluicing. Methods Data were collected on deaths, prevalence rates of infectious and endemic diseases, as well as on vector surveillance through the project entitled 'Three Gorges Population Health Survey System'. Results The main causes of death in the population living in the Three Gorges Reservoir Areas would include: circulatory system diseases, tumors, respiratory system diseases, injuries/poison and digestive system diseases. The number of deaths caused by the above said five kind of diseases accounted for 90.94% of the total number of deaths. The prevalence rates on Water-born diseases related to the sluicing of reservoir and zoonosis-bome diseases related to the changes of vectors were still low. The indoor and outdoor densities of rodents were 3.11% and 3.16%, both were higher than that in 2006 but lower than the average numbers in the five years prior to the sluicing. The constituent ratio of Apodemus agrarius had constantly risen since 2006. The density of mosquitoes found in livestock barns and human households was higher than that in 2006 but lower than the average number of the five-year studies prior to the sluicing. Conclusion Environment change after the sluicing of the Three Gorges Reservoir Areas did not seem to have obvious impact on the health status of the people living in the areas. However, to strengthen the surveillance on the biological features of the vectors which might have related to the transmission of diseases would be highly recommended.

Surveillance of schistosomiasis in Three Gorges Reservoir areas from 2002 to 2007 / 中国血吸虫病防治杂志

Objective To explore the potential risk factors of schistosomiasis transmission so as to provide evidence for setting up the surveillance scheme of schistosomiasis prevention and control. Methods The schistosome infection of local inhabitants, mobile population and stock from endemic areas were investigated from 2002 to 2007 by using IHA or ELISA technique. The historical endemic reports of Chongqing City and the schistosomiasis cases, and the plants imported from schistosomiasis endemic areas and Oncomelania snails were investigated. The behavior of local inhabitants was also investigated. Results The investigated people included 5 112 local inhabitants, 1 455 mobile people from schistosomiasis endemic areas and 1 744 residents returned from the endemic areas. The sero-positive rates of them were 0.57%, 1.44% and 0.86%, respectively. Eighteen cases of imported schistosomiasis were found. There were many plants and stock imported from the schistosomiasis endemic areas. No imported snail was found. The farming of local inhabitants depended on the cattle chiefly. The rate of the harmless lavatories was 14.88%. The local residents had the habit of water contact. Conclusion There are potential risk factors for schistosomiasis transmission in the Three Gorges Reservoir areas. The local residents have potential risk behavior of getting infection of Schistosoma japonicum. The surveillance should be emphasized on the mobile population, imported plants and stock from endemic areas.

Surveillance on endemic situation of schistosomiasis in national surveillance sites of Chongqing City in 2006 / 中国血吸虫病防治杂志

Objective To understand the correlative factors of impacting schistosomiasis prevalence so as to provide the scientific evidence for drawing up the control project in Three Gorges Reservoir areas.Methods The report system of schistosomiasis was set up,and the cases were investigated.The population were screened by indirect haemagglutination test(IHA),and the serum-positive people were examined with Kato-Katz technique.The livestock and plants imported from the schistosomiasis endemic areas were investigated.Results Eighty-eight floating people returning from schistosomiasis endemic areas and 107 floating persons from endemic areas were investigated,and the serum positive rates were 1.14% and 1.87%,respectively.No schistosome eggs were found in stool examinations.There was no livestock and plant imported from schistosomiasis endemic areas.The production of local inhabitants depended on mainly cattle,and the river water contact was popular.Conclusions There are infection resources of schistosomiasis imported from endemic areas,which has a potential risk of schistosomiasis prevalence.

INVESTIGATION ON IMPORT WAY OF SCHISTOSOMIASIS AND ONCOMELANIA SNAILS IN THREE GORGES RESERVOIR AREAS / 中国血吸虫病防治杂志

Objective To study the import way of schistosomiasis and the vector snail in Three Gorges Reservoir areas (TGR), so as to provide the reference for the surveillance, early warning of schistosomiasis.Methods A total of 256 movement population in Badong County and Zigui County and 1584 immigrants from TGR to the endemic area of Hubei Province were investigated by questionnaire, and screened by means of IHA and COPT. The farm cattle were surveyed in Badong County and Zigui County. Production of paper mills, the source of papermaking raw material, flowers and trees in gardens were investigated for snail survey. At the same time, current situation of immigrants in TGR was investigated. Social data (statistic yearbook, etc) and policy data of development of TGR were collected. Results No farm cattle from endemic area of schistosomiasis was found. In Hubei reach of TGR, the movenment population were mainly from the endemic area of schistosomiasis in Hubei Province. The positive rate of both IHA and COPY was 0 57%(1/175); the positive rate of both IHA in emigrants from TGR was 1 01%(12/1186). No Oncomelania snail was found in the introduced flowers and trees in garden. In paper mills, no reed from the endemic area of schistosomiasis was found. Migrants′ living and sanitary condition were improved after moving,but the production was not well arranged. Orange industry, travel industry, animal husbandry and fishery should be developed preferentially in the future. Conclusion Migrants from TGR to the endemic area of schistosomiasis and the movement population will be the mainly infection source. The problem on cattle as the infection source should be paid attention. It can't be excluded that snail will enter TGR together with the raw material for paper mills or flowers and trees. To develop orange industry will be good for the control of schistosomiasis; but the development of animal husbandry, fishery and travel industry will increase the risk of import of the infection source and snails to TGR.