[Effect evaluation of water conservancy project with ditches managed against Oncomelania hupensis in Yunnan Province].

OBJECTIVE: To evaluate the effect of hydraulic schistosomiasis control project with ditches managed on Oncomelania hupensis snail control. METHODS: From 2009 to 2011, the snail investigations and schistosomiasis surveillance were carried out in Dali City and Yongsheng County, two sites of national schistosomiasis surveillance. The history data of schistosomiasis control were collected and analyzed. RESULTS: At the harden sections of the water conservancy project with ditches managed in Shajing Village of Dali City, only one snail was found in 2010 with the density of living snails of 0.004 snails/0.1 m2, while the densities of living snails were respectively 0.080, 0.002 snails/0.1 m2 and 0.007 snails/0.1 m2 in unhardened sections of the project from 2009 to 2011. No snails were found in the harden sections of the water conservancy project with ditches managed in Gaojiacun Village of Yongsheng County, while the densities of living snails were respectively 0.040, 0.030 snails/0.1 m2 and 0.040 snails/0.1 m2 in unhardened sections of the project from 2009 to 2011. After the ditches were hardened, no infected snails were found from 2009 to 2011, and the appearance rate of frames with snails and density of living snails were both decreased, while they were both higher in unhardened ditches. CONCLUSIONS: The hydraulic schistosomiasis control project has obvious effect on control snails, but the maintain work should be strengthened after the project is completed.

Surveillance of Schistosomiasis in Yongsheng county of Lijiang city, Yunnan from 2002 to 2010 / 中国地方病学杂志

Objective To learn the effects of control measures,the screening situation and the epidemic situation of Schistosomiasis in Yongsheng county of Lijiang city of Yunnan province,and to provide a scientific basis for developing control strategies.Methods Annual surveillance data of Schistosomiasis of Yongsheng county from 2002 to 2010 were collected and analyzed by material retrospective method.Schistosomiasis screening situation,infection rate of people and cattle as well as snails area was statistically analyzed.Infection rate of people was from the screening results by indirect hemagglutination(IHA),and pathogenic examination of the positives(1 ∶ 10)was carried out through collection of eggs with nylon bag and hatching the stool.Infection rate of cattle was from etiology examination results by plastic cup pipe jacking method.Results From 2002 to 2010,257679 individuals were screened and 26540 cases (10.30％) were seropositive; with stool examination,451 (1.72％) were identified positive of 26233 persons; 603 (0.71％) were found positive of 85658 oxen.All of the positive detection rate of IHA method,the feces-positive detection rate in the population and the prevalence rate of oxen showed a declining trend(x2 =3615.53,785.68,434.50,all P＜ 0.05).The snails area was gradually reduced,the rate of snails environmental area was decline from 23.82％ in 2004 to 1.98％ in 2010.Conclusions The endemic situation of Schistosomiasis in Yongsheng county is controlled in the past eight years,but remains epidemic,and we will continue to strengthen monitoring,in order to achieve the goal of blocking the spread of Schistosomiasis.