Endemic situation of schistosomiasis after transmission- blocked for 4 years in Mianyang, Sichuan

Abstract

Objective To analyze the endemic situation of schistosomiasis in Mianyang ensued from the blocking of transmission of schistosomiasis, we provide evidence for the development of control strategies.

Methods The data regarding the endemic situation were retrospectively collected and analyzed in Mianyang City from 2016 to 2019.

Results Schistosomiasis is prevalent in 359 villages of 56 towns under the administrative 6 counties and districts of Mianyang city. Areas with oncomelania snails were 2 102.58 hm ² in history. The number of infected people and infected cattle in history was 96 078 and 28 701 respectively. Mianyang city has reached the national standard of schistosomiasis transmission blocking in 2015. Blood tests were carried out in 678 776 person-times, and revealed positive results 11 919 person-times from 2016 to 2019. The annual positive rate ranged from 1.01%-2.29%. Total 11 919 person-times received fecalexamination and no positive result. There was no acute schistosomiasis patient and new found advanced schistosomiasis cases in consecutive 4 years. There were 49 cases of advanced schistosomiasis alive. The total number of 25 068 cattle-times were carried out blood tests from 2016 to 2019, in which 278 are positive. The annual positive rate ranged from 0.22%-2.23%.825 cattle-times received fecal examination and no positive results. General survey covered an area of 16 469.2 hm ² throughout Mianyang, snails were found in 105.14-146.98 hm ² from 2016 to 2019. No infectious snails were detected. Oncomelania hupensis still existed in an area of 437.76 hm ² bythe end of 2019, distributed in 240 villages of 52 towns under the administrative 6 counties and districts.

Conclusions Currently, the endemic situation of schistosomiasis is at a low level in Mianyang City. But the risk of resurgence is still existing.The infectious source control, the surveillance works and health education should be strengthenedin order to strengthen the achievement.

Abstract

摘要： 目的 分析绵阳市达到血吸虫病传播阻断标准后的疫情, 为制订防治策略提供依据。 方法 收集绵阳市2016—2019年血吸虫病疫情数据, 进行描述性分析。 结果 全市有6个县市区、56个乡镇、359个村曾流行血吸虫病, 历史累计有螺面积2 102.58 hm2、血吸虫病人96 078例、病牛28 701头, 全市于2015年达到血吸虫病传播阻断标准。2016—2019年累计开展人群血检678 776人次, 阳性11 919人次, 各年度血检阳性率1.01%~2.29%; 粪检11 919人次, 无阳性发现。4年间全市无急血和新发晚血报告, 现存晚血病人49例。累计血检耕牛25 068头次, 阳性278头次, 年度阳性率0.22%~2.23%; 粪检825 头次, 无阳性发现。2016—2019 年, 共计查螺16 469.2 hm2, 查出钉螺面积105.14~146.98 hm2, 未查见感染性钉螺。至2019年末, 全市尚有437.76 hm2钉螺面积, 分布于6个县市区、52个乡镇、240个村。 结论 绵阳市血吸虫病疫情处于低流行状态, 但存在疫情回升的风险。今后应继续实施以传染源控制为主的综合防治策略, 加强监测, 积极开展健康教育, 以巩固血防成果。