湖沼型疫区不同血吸虫病传染源控制模式比较

Comparative evaluation of models for infectious source control of schistosomiasis in lake and marshland regions

目的比较不同血吸虫病传染源控制模式的效果,探索适合湖沼型疫情控制地区的防治模式。方法在湖北省公安县和监利县各选择2个镇,分别实施"以机代牛"和"封洲围栏、固定牧场"模式。收集调查点2008-2010年人畜病情、螺情及野粪污染情况,并进行分析。结果 2010年"以机代牛"模式观察组居民血吸虫感染率与2008年相比下降了56.82%,差异有统计学意义(χ2=78.197,P<0.01),且观察组下降幅度大于对照组;耕牛血吸虫感染率、感染螺密度和钉螺感染率均下降至0;观察组未发现野粪,对照组发现野粪58份,经检测均为阴性。2010年"封洲围栏、固定牧场"模式观察组居民血吸虫感染率较2008年下降了39.00%,差异无统计学意义(χ2=1.594,P>0.05);耕牛血吸虫感染率下降了43.98%,前后差异无统计学意义(χ2=0.751,P>0.05);观察组活螺密度下降了89.83%,对照组上升了6.80%;观察组收集野粪11份,阳性2份,阳性率为18.18%;对照组收集野粪7份,经检查均为阴性。两种模式实施2年,均未发现急性血吸虫病人和新发晚期血吸虫病人。结论 "以机代牛""、封洲围栏、固定牧场"是湖沼型疫区控制血吸虫病流行的主要措施,前者适于垸内地区,后者适于垸外地区。

Objective To compare the effect of different models for the control of infectious source of schistosomiasis, so as to explore the control models suitable for lake and marshland regions. Methods The models of ＂replacement of cattle with machine＂ and ＂grazing prohibition and establishing fixed pasture＂ were implemented in 2 towns of Gong’an and Jianli counties, Hubei Province, respectively, and the data of infection situation of human and livestock, Oncomelania hupensis snail situation and the contamination status of wild faeces were collected and analyzed from 2008 to 2010. Results In 2010, for the model of ＂replacement of cattle with machine＂, the infection rate of residents in the observation group decreased by 56.82% comparing to that in 2008, the difference had a statistical significance （[χ2]= 78.197, P〈0.01）, and the decrease extent in the observation group was larger than that in the control group; the infection rates of cattle and snails, and the density of infected snails of the former were all decreased to 0. No wild faeces were discovered in the observation group, while 58 pieces of wild faeces were discovered but no schistosome eggs were found in these faeces in the control group. In 2010, for the model of ＂grazing prohibition and establishing fixed pasture＂, the infection rate of residents in the observation group decreased by 39.00% without a statistic significance （[χ2]=1.594,P〉0.05）, and the infection rate of cattle decreased by 43.98% without a statistically significant difference （[χ2]=0.751,P〉0.05） comparing to those in 2008. The density of living snails decreased by 89.83% in the observation group, while that in the control group increased by 6.80%. A total of 11 pieces of wild faeces were collected in the observation group, with a positive rate of 18.18%, and 7 pieces were collected in the control group, all of which were negative. During the 2 years, no acute and advanced schistosomiasis patients were newly discovered. Conclusions ＂Replacement of cattle with machine＂ and ＂grazing prohibition and establishing fixed pasture＂ are the main measures for schistosomiasis control in lake and marshland regions, the former is suitable for inner embankment regions, while the latter is suitable for the outer-embankment areas.