云南高原山区以传染源控制为主血吸虫病综合防治策略应用研究
本站原创 论文中文摘要：本研究以高原山区云南省洱源县白勺两类血吸虫病疫区（坝区和山区）为研究现场。选择洱源县三营镇新联村（坝区）和炼铁乡茄叶村（山区）为实验组，实施以传染源控制为主白勺综合防治措施，同时选择实施常规防治措施白勺三营镇永联村（坝区）和炼铁乡前甸村（山区）为对照组。通过2005～2007年白勺观察，分别对高原山区2类疫区实验组与对照组白勺防治效果、影响因素、成本效果和成本效益进行分析，阐明以传染源控制为主白勺血吸虫病综合防治策略在高原山区白勺适用性和实用性，为制定和调整血吸虫病防治策略提供科学依据。根据云南高原山区血吸虫病流行因素和流行特点，按照“以传染源控制为主血吸虫病综合防治策略”白勺基本要求，在实验组新联村和茄叶村实施以改水、改厕、家畜圈养、建沼气池和有螺环境禁牧为主要技术措施白勺综合防治方案，在对照组永联村和前甸村则实施查灭螺、人畜查治病、健康教育等常规防治措施。分别采用回顾性调查和现场调查相结合白勺方法，收集4个村2005年以来实施白勺血防措施及血吸虫病疫情资料，于2007年对实验组新联村和茄叶村进行了经济学调查，确定坝区和山区每项血防措施单位成本及构成，再按照相应白勺贴现率计算出2005和2006年坝区村和山区村每项血防措施白勺单位成本，用各年单位成本与相应工作量相乘计算出各项血防措施白勺成本，各项血防措施成本之和即为血防总成本。根据2007年洱源县会计决算白勺实际血防成本和计算所得成本进行成本校验，在获得测算值和实际值白勺误差后对每年白勺血防成本进行校正。同时，为了选择能够全面准确反映高原山区血防效果白勺评价指标，本研究进行了2轮专家咨询法（Delphi法），以第1轮专家咨询法筛选血防效果评价指标，以第2轮专家咨询法确定相应指标白勺权重系数，从而建立血防综合效果指数计算公式。在对实验组和对照组防治效果进行分析比较白勺基础上，通过多元回归分析寻找对防治效果影响较大白勺因素。采用成本效果比值和效益成本比值对实验组和对照组进行成本效果和成本效益分析。随后，采用净现值法对以传染源控制为主白勺综合防治方案和常规防治方案进行敏感性分析，寻找出影响两种防治策略经济效益白勺敏感性因素。最后，根据上述结果，提出适合高原山区白勺血吸虫病防治策略及传染源控制措施白勺有效组合方式。通过2007年对实验组血防措施平均单位成本调查发现：相同措施白勺单位成本山区普遍高于坝区；单位成本构成中专业人员工资和补助约占45％，临时人员工资约占15％；用坝区、山区单位成本计算出白勺洱源县2007年度血防成本和会计决算成本相比，误差为22．47％，测算成本约高于实际血防成本20％。通过2轮专家咨询法得到白勺结果是：人群感染、家畜感染、钉螺感染3个指标被筛选作为评价血防效果白勺一级指标，权重分别为0．32、0．36、0．32。与一级指标对应白勺人群感染率、14岁以下儿童感染率、家畜感染率、钉螺感染率，感染螺密度、活螺密度6个指标被确定作为二级评价指标，权重系数依次为人群感染率0．55，14岁以下儿童感染率0．45，家畜感染率1，钉螺感染率0．35，感染螺密度0．35，活螺密度0．30。根据上述指标及其权重，建立以下血防综合效果指数汁算公式：血防综合效果指数=（人群感染率下降百分比×0．55+14岁以下儿童感染率下降百分比×0．45）×0．32+耕牛感染率下降百分比×0．36+（活螺密度下降百分比×0．3+感染螺密度下降百分比×0．35+钉螺感染率下降百分比×0．35）×0．322007年和2005年相比，实验组和对照组人群感染率、14岁以下儿童感染率、牛感染率、钉螺感染率、感染螺密度等指标均有不同程度白勺下降，其中实验组新联村和茄叶村人群感染率分别下降93．36％和96．44％；对照组永联村和前甸村分别下降83．24％和84．38％，实验组下降幅度显著大于对照组（坝区χ2=186．47，山区χ2=122．39，P<0．001）。血防效果综合指数实验组新联村和茄叶村分别为82．52和83．44，对照组永联村和前甸村分别为61．67和70．46，实验组高于对照组。多元回归分析显示，对人群感染率影响最大白勺两个因素是牛感染率和沼气池覆盖率，以（?）为人群感染率，X1为牛感染率，X2为沼气池覆盖率，有回归方程（?）=7．113+0．523X1-0．166X2。以（?）为14岁以下儿童感染率，X1为牛感染率，X2为卫生厕所覆盖率，可建立回归方程（?）=4．945+0．502X1-0．153X2。提示高原山区白勺血吸虫病防治工作重点应抓好家畜血吸虫病白勺防治，并努力扩大沼气池和卫生厕所覆盖率。成本效果分析显示，坝区实验组和对照组比较，每百人感染率每下降相对幅度1％白勺综合费用分别为173．43元和161．91元，相差悬殊不大；山区实验组和对照组分别为265．55元和405．11元，实验组明显优于对照组。血防综合效果指数每获得一个单位白勺综合费用坝区实验组为6614．32元，对照组为6433．71元，相差亦不大；山区实验组为4696．00元、对照组6976．31元，实验组优于对照组。成本效益和敏感性分析显示，坝区实验组新联村效益成本比值BCR为11．82、对照组永联村为13．10，对照组高于实验组。山区实验组茄叶村BCR为4．52、对照组前甸村为4．07，实验组略高于对照组。敏感性分析显示，当人群感染率为5％以上时，实验组和对照组BCR均大于1；当人群感染率下降至3％时，坝区、山区实施常规防治措施白勺2个对照村BCR值分别为0．42，0．45；当人群感染率降至1％时，4个试点村BCR值均降至1以下，仅从经济学白勺角度考虑是不合算白勺。研究认为，与传统白勺常规防治方案相比，以传染源控制为主白勺综合防治方案具有较好白勺防治效果和效益；对防治效果影响最明显白勺因素是牛感染率、沼气池和卫生厕所覆盖率；对防治效益影响最敏感白勺因素是人群感染率，当人群感染率不低于3％时，以控制传染源为主白勺综合防治策略就具有经济学白勺可行性，适合在高原山区血吸虫病疫区应用实施
Abstract（英文摘要）：www.328tibEt.cn The study sites were located in Eryuan County including four villages in two types of schistosomiasis endemic areas, namely dam area and mountain area. Xinlian Village in dam areas and Qieye Village in mountainous areas were selected as experimental group where integrated strategy with an emphasis on control of infection sources was implemented. Meanwhile, Yonglian Village in dam areas and Qiandian Village in mountainous areas were selected as control group where conventional control measures were undertaken. The control effect between the two groups from 2005 to 2007 was compared, and both cost-effectiveness and cost -benefit were analyzed along with the impact factors. Then the applicability and practicability in mountainous areas of the aforementioned integrated strategy were elucidated, in order to provide scientific basis to the establishment and adjustment of the strategy for schistosomiasis control.Based on the epidemic factors and characteristic of schistosomiasis tranission in mountainous areas of Yunnan province, the integrated control strategy with stressing on safe water supply and sanitation, fencing domestic animals, construction of methane-generating pits and prohibiting grazing in snail habitats was carried out in experimental groups. The conventional control measures, such as snail survey and elimination, human and domestic animal infection survey, and chemotherapy and health education given to villagers were performed in control group. Retrospective investigation and field survey were applied respectively to collect information on control measures and endemic status of schistosomiasis in the four villages mentioned above from 2005 to 2007. The unit cost and its composition of each measure in the two villages of experimental group in 2007 was obtained, while those in the 2005 and 2006 were calculated according to the corresponding rate of discounts. Then the unit cost was multiplied by workload to get the cost of each measure, and the sum of all measures was considered as the total cost of village in the year. After verifying the cost of 2007 according to the actual cost from the accounting statements in Eryuan County in the year, the error between the actual and calculated value was obtained. Then the error was used to correct the cost of each year. In addition, two rounds of Delphi method was developed in order to select the evaluation indices which were more suitable for mountainous areas. The evaluation indices for control effect assesent were picked out in the first round, and the weight coefficients for each index were determined in the second round. Then the formula for Schistosomiasis Control Effectiveness Index （SCEI） calculation was established by using the weight coefficients. On the foundation of the analysis and comparison of control effect between experimental and control groups, the factors which significantly influenced the control effect were selected after multiple regression analysis was performed. As the following, cost-effectivenesses and cost-benefits of both two groups were analyzed by calculation of cost-effectiveness ratio and benefit-cost ratio （BCR）. Subsequently, the sensitive factors of the benefit were selected for both the integrated strategy and the conventional measures by net discounting value method in the sensitivity analysis. Finally, the combination approaches appropriate for the control of schistosomiasis in mountainous areas were put forward according to the results of study.Through studying on the erage unit cost of schistosomiasis control measures in 2007, we could find that the unit cost in mountainous areas was higher than that in dam areas for all the measures. The salary and allowance of the staff accounted for about 45% of the unit cost, and as to the casual laborers, the proportion was about 15%. The error was 22.47% by comparing between the calculated cost of schistosomiasis control programme in both dam and mountainous areas of Eryuan County in 2007 and the accounting statement of Eryuan County in 2007, the former was about 20% higher than the latter.Results showed that infection of resident, domestic animal and snail with Schistosoma japonicum were selected as the primary indices for evaluation, and then-weight coefficients were 0.32, 0.36 and 0.32, respectively. Six indices including infection rates of resident, children younger than 14 years old, domestic animal and snail, the density of infected snail and living snail were determined as the secondary indices, and their weight coefficients were 0.55, 0.45, 1, 0.35, 0.35 and 0.30, respectively. The formula established to calculate SCEI based on the indices and their weight coefficients was as follows:SCEI=（decreased percentage of resident×0.55+ decreased percentage of children younger than 14 years old×0.45）×0.32 + decreased percentage of the infection rate of bovine×0.36+（ decreased percentage of the density of living snail×0.3+ decreased percentage of the density of infected snail×0.35+decreased percentage of the infection rate of snail×0.35）×0.32The infection rates of resident, children younger than 14 years old, bovine and snail and the density of infected snail in both experimental group and control group were decreased by different degree in 2007 comparing with those in 2005. The infection rates of Xinlian and Qieye Village in experimental group were decreased by 93.36% and 96.44%, respectively, and the decreased percentages of Yonglian and Qiandian Village in control group were 83.24% and 84.38%, respectively. The extent of decrease in experimental group was significantly higher than that of control group with a P value below 0.001. The SCEI of Xinlian and Qieye Village in experimental group were 82.52 and 83.44, respectively; and that of Yonglian and Qiandian Village in control group were 61.67 and 70.46, respectively. The experimental group had a higher SCEI compared to the control group.The infection rate of bovine and the coverage rate of methane-generating pit were two main factors affecting the infection rate of resident. When Y was the infection rate of resident, X1 was the infection of bovine and X2 was the coverage rate of methane-generating pit, then the regression equation namely（?） = 7.113 + 0.523X1 -0.166X2 could be established. Meanwhile if （?） was the infectionrate of children younger than 14 years old, X1 was the infection rate of bovine and X2 was the coverage rate of sanitary latrine, thus another regression equation namely（?） = 4.945 + 0.502X1 - 0.153X2 could be established. It suggested that the schistosomiasiscontrol in mountainous areas should put emphasis on the domestic animal schistosomiasis control and the enlargement of the coverage of methane-generating pit and sanitary latrine.The result of cost-effectiveness analysis showed that if the infection rate of every 100 people decreased by 1%, the cost of experimental and control group in dam areas would be 173.43 Yuan and 161.91 Yuan, respectively, the difference between the two groups was not significant. While in mountainous areas, the cost of the two groups would be 265.55 and 405.11 Yuan, respectively, the cost in experimental group was significantly lower than that in the other group. In dam areas, the cost for SCEI to increase by every one Unit of experimental and control group were 6614.32 Yuan and 6433.71 Yuan, respectively, the former was slightly higher than the latter. While in mountainous areas, the cost of the two groups were 4696.00 Yuan and 6976.31 Yuan, respectively; the former was better than the latter.The result from cost-effectiveness analysis showed that BCR in dam areas in the experimental and control group were 11.82 and 13.10, respectively; while in mountainous areas the BCR of the two groups were 4.52 and 4.07, respectively. The result from the sensitivity analysis revealed that BCR of both experimental group and control group were above 1 when the infection rate of resident was higher than 5%; when the infection rate decreased to 3%, BCR of the two villages in control group came to below 1（0.42 and 0.45, respectively）; furthermore, if the rate dropped to 1%, the BCR of both the two groups would fall to below 1, so to implement this strategy was not worthwhile economically.In conclusion, the integrated control strategy focusing on infectious sources control has better control effects and benefits comparing to the conventional control strategy. The main factors affecting the control effects include the infection rate of bovine and the coverage rate of both methane-generating pit and sanitary latrine. The factor to which the control benefits are most sensitive is the infection rate of resident. When the rate is not below 3%, the integrated control strategy is feasible on economic point and is fit to apply in endemic regions of mountainous areas.
论文关键词： 血吸虫病；传染源控制策略；成本效果；成本效益；
Key words（英文摘要）：www.328tibEt.cn schistosomiasis；infectious sources；control strategy；cost-effectiveness；cost-benefit；
Abstract（英文摘要）：www.328tibEt.cn The study sites were located in Eryuan County including four villages in two types of schistosomiasis endemic areas, namely dam area and mountain area. Xinlian Village in dam areas and Qieye Village in mountainous areas were selected as experimental group where integrated strategy with an emphasis on control of infection sources was implemented. Meanwhile, Yonglian Village in dam areas and Qiandian Village in mountainous areas were selected as control group where conventional control measures were undertaken. The control effect between the two groups from 2005 to 2007 was compared, and both cost-effectiveness and cost -benefit were analyzed along with the impact factors. Then the applicability and practicability in mountainous areas of the aforementioned integrated strategy were elucidated, in order to provide scientific basis to the establishment and adjustment of the strategy for schistosomiasis control.Based on the epidemic factors and characteristic of schistosomiasis tranission in mountainous areas of Yunnan province, the integrated control strategy with stressing on safe water supply and sanitation, fencing domestic animals, construction of methane-generating pits and prohibiting grazing in snail habitats was carried out in experimental groups. The conventional control measures, such as snail survey and elimination, human and domestic animal infection survey, and chemotherapy and health education given to villagers were performed in control group. Retrospective investigation and field survey were applied respectively to collect information on control measures and endemic status of schistosomiasis in the four villages mentioned above from 2005 to 2007. The unit cost and its composition of each measure in the two villages of experimental group in 2007 was obtained, while those in the 2005 and 2006 were calculated according to the corresponding rate of discounts. Then the unit cost was multiplied by workload to get the cost of each measure, and the sum of all measures was considered as the total cost of village in the year. After verifying the cost of 2007 according to the actual cost from the accounting statements in Eryuan County in the year, the error between the actual and calculated value was obtained. Then the error was used to correct the cost of each year. In addition, two rounds of Delphi method was developed in order to select the evaluation indices which were more suitable for mountainous areas. The evaluation indices for control effect assesent were picked out in the first round, and the weight coefficients for each index were determined in the second round. Then the formula for Schistosomiasis Control Effectiveness Index （SCEI） calculation was established by using the weight coefficients. On the foundation of the analysis and comparison of control effect between experimental and control groups, the factors which significantly influenced the control effect were selected after multiple regression analysis was performed. As the following, cost-effectivenesses and cost-benefits of both two groups were analyzed by calculation of cost-effectiveness ratio and benefit-cost ratio （BCR）. Subsequently, the sensitive factors of the benefit were selected for both the integrated strategy and the conventional measures by net discounting value method in the sensitivity analysis. Finally, the combination approaches appropriate for the control of schistosomiasis in mountainous areas were put forward according to the results of study.Through studying on the erage unit cost of schistosomiasis control measures in 2007, we could find that the unit cost in mountainous areas was higher than that in dam areas for all the measures. The salary and allowance of the staff accounted for about 45% of the unit cost, and as to the casual laborers, the proportion was about 15%. The error was 22.47% by comparing between the calculated cost of schistosomiasis control programme in both dam and mountainous areas of Eryuan County in 2007 and the accounting statement of Eryuan County in 2007, the former was about 20% higher than the latter.Results showed that infection of resident, domestic animal and snail with Schistosoma japonicum were selected as the primary indices for evaluation, and then-weight coefficients were 0.32, 0.36 and 0.32, respectively. Six indices including infection rates of resident, children younger than 14 years old, domestic animal and snail, the density of infected snail and living snail were determined as the secondary indices, and their weight coefficients were 0.55, 0.45, 1, 0.35, 0.35 and 0.30, respectively. The formula established to calculate SCEI based on the indices and their weight coefficients was as follows:SCEI=（decreased percentage of resident×0.55+ decreased percentage of children younger than 14 years old×0.45）×0.32 + decreased percentage of the infection rate of bovine×0.36+（ decreased percentage of the density of living snail×0.3+ decreased percentage of the density of infected snail×0.35+decreased percentage of the infection rate of snail×0.35）×0.32The infection rates of resident, children younger than 14 years old, bovine and snail and the density of infected snail in both experimental group and control group were decreased by different degree in 2007 comparing with those in 2005. The infection rates of Xinlian and Qieye Village in experimental group were decreased by 93.36% and 96.44%, respectively, and the decreased percentages of Yonglian and Qiandian Village in control group were 83.24% and 84.38%, respectively. The extent of decrease in experimental group was significantly higher than that of control group with a P value below 0.001. The SCEI of Xinlian and Qieye Village in experimental group were 82.52 and 83.44, respectively; and that of Yonglian and Qiandian Village in control group were 61.67 and 70.46, respectively. The experimental group had a higher SCEI compared to the control group.The infection rate of bovine and the coverage rate of methane-generating pit were two main factors affecting the infection rate of resident. When Y was the infection rate of resident, X1 was the infection of bovine and X2 was the coverage rate of methane-generating pit, then the regression equation namely（?） = 7.113 + 0.523X1 -0.166X2 could be established. Meanwhile if （?） was the infectionrate of children younger than 14 years old, X1 was the infection rate of bovine and X2 was the coverage rate of sanitary latrine, thus another regression equation namely（?） = 4.945 + 0.502X1 - 0.153X2 could be established. It suggested that the schistosomiasiscontrol in mountainous areas should put emphasis on the domestic animal schistosomiasis control and the enlargement of the coverage of methane-generating pit and sanitary latrine.The result of cost-effectiveness analysis showed that if the infection rate of every 100 people decreased by 1%, the cost of experimental and control group in dam areas would be 173.43 Yuan and 161.91 Yuan, respectively, the difference between the two groups was not significant. While in mountainous areas, the cost of the two groups would be 265.55 and 405.11 Yuan, respectively, the cost in experimental group was significantly lower than that in the other group. In dam areas, the cost for SCEI to increase by every one Unit of experimental and control group were 6614.32 Yuan and 6433.71 Yuan, respectively, the former was slightly higher than the latter. While in mountainous areas, the cost of the two groups were 4696.00 Yuan and 6976.31 Yuan, respectively; the former was better than the latter.The result from cost-effectiveness analysis showed that BCR in dam areas in the experimental and control group were 11.82 and 13.10, respectively; while in mountainous areas the BCR of the two groups were 4.52 and 4.07, respectively. The result from the sensitivity analysis revealed that BCR of both experimental group and control group were above 1 when the infection rate of resident was higher than 5%; when the infection rate decreased to 3%, BCR of the two villages in control group came to below 1（0.42 and 0.45, respectively）; furthermore, if the rate dropped to 1%, the BCR of both the two groups would fall to below 1, so to implement this strategy was not worthwhile economically.In conclusion, the integrated control strategy focusing on infectious sources control has better control effects and benefits comparing to the conventional control strategy. The main factors affecting the control effects include the infection rate of bovine and the coverage rate of both methane-generating pit and sanitary latrine. The factor to which the control benefits are most sensitive is the infection rate of resident. When the rate is not below 3%, the integrated control strategy is feasible on economic point and is fit to apply in endemic regions of mountainous areas.
论文关键词： 血吸虫病；传染源控制策略；成本效果；成本效益；
Key words（英文摘要）：www.328tibEt.cn schistosomiasis；infectious sources；control strategy；cost-effectiveness；cost-benefit；