防止白蛉叮吸以降低犬源型黑热病传播风险的效果评价

目的应用干预措施防止白蛉-犬接触,探索控制黑热病传播的有效方法。方法在文县选择近5年发病率和犬数相近的19个村,以乡为单位分为3组在6~9月实施干预措施。对照组(铁楼乡)无干预措施;石坊乡采取的干预措施为犬喷洒高效氟氯氰菊酯,在6月和8月各一次;石鸡坝乡为采取犬喷洒高效氟氯氰菊酯2次,同时居民使用杀虫剂浸泡蚊帐。干血斑法采集干预前后血清,免疫荧光分析(Immunoflurescence,IFA)法检测黑热病血清抗体。应用χ2检验分析干预前后及干预后各组间血清抗体阳性率的差异。结果家犬喷药组干预前检测血清抗体1 028份,阳性率为5.06%,干预后血清754份,阳性率为3.45%,干预前后差异有统计学意义(χ2=13.76,P﹥0.05)。犬杀虫剂喷洒和悬挂药浸蚊帐组干预前检测血清抗体1 342份,阳性率为4.62%;干预后检测549份,阳性率为1.82%,干预前后差异有统计学意义(χ2=2.87,P﹥0.05)。干预后家犬药喷组、联用蚊帐组与对照组血清抗体阳性率χ2分析比较,差异均有统计学意义(前者χ2=15.27,P﹥0.05;后者χ2=5.12,P﹥0.05)。结论夏秋两季家犬杀虫剂喷洒能有效防止白蛉-犬接触,切断黑热病传播环节,降低黑热病高流行区人群发病率。

Effect of sand-fly control on interruption of leishmaniasis transmission

Objective To analyze the effect of sand-fly control in prevention of transmission of Leishmanisis. Methods Nineteen villages in Wenxian County in Southern Gansu with similar incidence of leishmaniasis were chosen and divided to three groups （three townships） , control group （Tielou township） without any intervention ,and two intervention groups （Shijiba and Shifang township）.Dogs of Shifang Country treated with spraying of insecticide. In another intervention group, Shijiba country, not only dogs treated with insecticide spray, but also insecticide soaked mosquito net suspended in the livingroom to prevent dwellers from Phlebotomine sand-fly sucking which result in infection of Leishimania. Serum samples collected using DBS method at the interval of intervention measures applied in the season of sand-fly breed largely. Then serum IgG of Leishimania examined using IFA. Antibody level compared between two stages of intervention by three groups respectively. After the intervention, positive rate also compared among the groups by χ2 analysis. Results In intervention group dogs sprayed of insecticide, 1 028 serum samples examined before intervention, antibody positive rate was 5.06%. After intervention , 745 serum samples examined that positive rate was 3.45%, a significantly difference was found between two stages （χ2=13.76,P〈0.005）.In another intervention group, Shijiba country, 1342 serum samples examined before intervention, antibody positive rate was 4.62%, after intervention 549 serum samples examined that positive rate was 1.82%, a significantly difference was also found between two stages （χ2=2.87, P〈0.05）. After the intervention measures applied, Serum antibody positive rate of two intervention group compared with control group using χ2analysis. When Shijiba country compared with control group, significantly difference existed（χ2=15.27, P〈0.005）, and another group, Shifang country, positive rate decreased with significances in statistics（χ2=5.12, P〈0.05）. Conclusion D