2004-2019年苏州市吴中区日本血吸虫病疫情监测分析

Surveillance and analysis on the endemic situation of Schistosomiasis japonica in Wuzhong district,Suzhou,from 2004 to 2019

目的了解苏州市吴中区血吸虫病传播阻断后疫情现状和变化趋势,为制定和完善血吸虫病监测方案提供依据。方法按照全国血吸虫病疫情监测方案对吴中区血吸虫病疫情进行监测,采取单纯随机抽样方法对吴中区各乡镇常住居民和流动人群,开展血清学间接血凝试验法(IHA)检测,血检阳性者进一步粪检(尼龙绢袋集卵孵化法或改良加藤氏法),同时对重点人群进行粪检。对2004-2019年查治病、查灭螺等数据进行分析,在此基础上进行疫情预测。结果2004-2019年共检测185815人次,未发现血吸虫病例。其中,2011-2019年血清学共检查本地人群52087人次,血检阳性率为0.301%(157/52087);流动人群20479人次,血检阳性率为0.542%(111/20479);2004-2019年间人群血检阳性率呈上升趋势,差异有统计学意义(Z=3.869,P<0.001);粪检3519人次,均阴性。共查螺3700.870 hm^(2),有螺面积25.790 hm^(2),总体有上升趋势,以山区环境为主,主要分布在光福、东山、金庭等乡镇。共查螺55371框,有螺框出现率为4.089%(2264/55371),各年间呈下降趋势,且差异有统计学意义(Z=-2.836,P=0.005)。查获活螺7900只,活螺密度0.143只/框,有下降趋势;解剖钉螺8574只,未发现阳性钉螺。药物灭螺90.906 hm^(2),无显著变化趋势。2020-2024年血清阳性率、有螺框出现率和活螺密度的5年预测值分别为0.616%、0.884%和0.082只/框,各年有螺面积预测值分别为15.028、6.296、13.004、7.852和11.809 hm^(2)。结论当地无血吸虫病疫情,且无阳性钉螺,但有螺面积波动较大,建议加强钉螺监测。

Objective To investigate the endemic situation of Schistosomiasis japonica and its trend after transmission interruption in Wuzhong district of Suzhou,and provide science evidence for the improvement of schistosomiasis surveillance program.Methods Statistical analyses were conducted on data of schistosomiasis investigation and treatment,snail control and health education from the National Schistosomiasis Epidemic Monitoring Program during 2004 to 2019,and then epidemic prediction was made.Results From 2004 to 2019,a total of 185815 person-time were examined and no suspected cases were reported.A total of 52087 of local persons were serologically examined,and the seropositive rate was 0.301%(157/52087).The seropositive rate in floating people was 0.542%(111/20479).During the period,the seropositive rates in the population were significantly different,showing an upward trend.A total of 3519 stool tests were performed,all of which were negative.A total area of 3700.870 hm^(2)were investigated,and the area of snail habitats was 25.790 hm^(2),showing an upward trend,mainly in mountainous areas,locating in Guangfu,Dongshan and Jinting townships.A total of 55371 frames(0.11 m^(2))were examined for snails and the proportion of frames with snails was 4.089%(2264/55371),which showed a significant difference and a decreasing trend(Z=-2.836,P=0.005).A total of 7900 snails were captured and the average snail density was 0.143 per frame,showing a decreasing trend.A total of 8574 snails were dissected and no positive snails were found.The molluscicidal area was 90.906 hm^(2)showed no significant trend.The 2020-2024 seroprevalence,frame occurrence and live screw density were 0.616%,0.884%and 0.082/box respectively,and the predicted values of screw area in each year were 15.028,6.296,13.004,7.852 and 11.809 hm^(2),respectively Conclusions There was no schistosomiasis epidemic and no infected snails in the area,but the area of snail habitats fluctuated greatly.It was suggested that relevant local departments had strengthened snail monitoring.