水利血防综合治理对降低垸内型血吸虫病流行区疫情的效果研究

Study of the effect on reduction of schistosomiasis endemic situation by water conservancy comprehensive measures in the area of embankment schistosomiasis endemic type

目的对西干渠流域水利血防综合治理后疫情变化进行效果评估，为垸内型血吸虫病流行区防治策略实施提供参考。方法江陵县西干渠流域500m内进行支渠水利血防治理的31个行政村为观察村．500m外的未进行水利血防治理的167个村为对照村。有螺河道水利血防治理采取先药物灭螺。再开挖疏浚并修建沉螺池。收集2006-2014年年报资料及各类防治资料，分析人、畜、螺感染率等疫情指标。结果江陵县2005年人、畜血吸虫病感染率11．83％、6．11％，钉螺感染率0．4187％。自水利血防综合治理工程实施起，完成药物浸杀灭螺380．50ha（1ha=10000m^2），河道疏挖4576400m^3，开新填旧完成土方开挖187000m^3、回填151200m^3。修建沉螺池12座．硬化渠道12km。2006—2014年观察村人、畜血吸虫病感染率分别从2006年的4．39％、11．75％下降至2014年的0．50％、0．降幅达88．56％、100％。观察村2011年阳性钉螺面积21600m^2．较2006年降幅达94.46％（2．16／39．00）。观察村2006-2009年人群感染率与对照村人群感染率差异有统计学意义（χ^2=64．06、52．94、36．01、6．96，P值均〈0．01），观察村人群血吸虫病感染率高于对照村。2010年后人群血吸虫病感染率差异没有统计学意义（χ^2=2．33、0．30、0．59，P值均〉0．05）。2006-2008年观察村与对照村钉螺感染率差异有统计学意义（χ^2=827．48、395．68、164．88、6．96，P值均〈0．01），观察村钉螺感染率为0．5221％、0．2833％、0．1670％，明显高于对照村的0．1598％、0．0885％、0．0643％。项目竣工后2009-2011年观察村与对照村钉螺感染率差异有统计学意义（χ^2=37．45、9．35、33．65．P值均〈0．01）。观察村钉螺感染率0．0448％、0．0454％、0．0070％，明显低于对照村的0．0971％、0．0659％、0．0330％。结论在垸内型血吸虫病流行区对主要灌溉水系进行水利血防综合治理．这对控制血吸虫病疫情起到重要作用。

Objective To evaluate the schistosomiasis endemic situation in the drainage area of Xigan Canal after control by water conservancy comprehensive measures in order to offer evidence for schistosomiasis control of embankment type. Methods In the drainage area of Xigan Canal around 500 m, 31 villages where the water conservancy comprehensive measures were complemented were selected as study sites, other 167 villages out of 500 m without water conservancy comprehensive measures were selected as control sites. The water conservancy comprehensive measures consisted of killing snail by molluscicide firstly, digging and dredging secondly, and setting up snail collection and killing pools thirdly. The data of schistosomiasis situation and control of 2006-2014 were collected, and the index of human, cattle and snail infection were analyzed. Results The schistosomiasis infection rate of people and livestock was 11.83% and 6.11% respectively, and the infection rate of snail was 0.418 7%. This comprehensive measures of water conservancy in schistosomiasis control projects an area of 380.50 ha （1 ha=10 000 m^2） was completed with molluscide treatment, 4 576 400 m^3 with excavation dredging, and 187 000 m^3 with earth excavation, and 151 200 m^3 with backfill, 12 snail-setting pools were built and 12 km channel hardened. From 2006 to 2014, the schistosomiasis infection rate of human decreased from 4.39% to 0, a decline rate of 88.56%, and the schistosomiasis infection rate of livestock fell from 11.75% to 0, a decline rate of 100% in the study villages. The area of positive snail shrank year by year, and it was 2.16 ha in 2011 in the study village, with a decline by 94.96% （2.16/39.00）. The difference of schistosomiasis infection rate of people between observation villages and control villages had statistic significance by Chi-square test（χ^2=64.06, 52.94, 36.01, 6.96, P〈0.01 ） during 2006- 2009, and the schistosomiasis infection rate of study villages was higher than that of control villages. But after 2010, the schistosomiasis infection rate had no statistic difference（χ^2=2.33, 0.30, 0.59, P〉0.01 ）. The different infection rate of snail between study village and control village had statistic significance （χ^2=827.48, 395.68, 164.88, 6.96, P〈0.01）. The infection rate of snail was 0.522 1%, 0.283 3%, 0.167 0% in study villages in 2006, 2007, 2008 respectively, and it was higher than that of control villages （0.159 8%, 0.088 5%, 0.064 3%）. After the completion of this project, there was statistic significance （χ^2=37.45, 9.35, 33.65, P〈0.01） in the infection rate of snail between study villages and control villages during 2009-2011. The annual infection rate of snail was 0.044 8%, 0.045 4%, 0.007 0% in study village during 2009-2011, much lower than that of control village（0.097 1%, 0.065 9%, 0.033 0%）. Conclusion In the area of embankment type of schistosomiasis, the schistosomiasis endemic situation was reduced by water comprehensive measures.