Objective: To analyze the endemic situation of schistosomiasis in national surveillance sites of Zhejiang Province, so as to provide the scientific evidence for formulating the new schistosomiasis surveillance program and consolidating schistosomiasis elimination achievements.
Methods: A total of 54 to 55 national surveillance sites and 6 risk monitoring sites were assigned in historical endemic regions of Zhejiang Province from 2015 to 2019, where the Schistosoma japonicum infections in humans, livestock, snails and wild feces were monitored. All data pertaining to the surveillance results were descriptively analyzed.
Results: There were 34 530 person-time local residents receiving serological screening for S. japonicum infections in national surveillance sites of Zhejiang Province from 2015 to 2019, and the seroprevalance of S. japonicum infections were 0.29% to 0.68%; however, no egg-positives were detected. During the period from 2015 to 2019, there were 62 086 person-time mobile populations receiving serological screening for S. japonicum infections in national surveillance sites of Zhejiang Province, and the seroprevalance of S. japonicum infections were 0.32% to 0.56%; additionally, there were 27 egg-positives identified, including 3 imported cases with schistosomiasis haematobia and one case with acute schistosomiasis japonica, indicating that the adjusted prevalence of Schistosoma infections were 0.01% to 0.07% among mobile populations. A total of 829 livestock were examined for S. japonicum infections, with no positives detected. There were 10.55 hm2 and 2.89 hm2 snail habitats found in national surveillance sites and risk monitoring sites of Zhejiang Province during the 5-year period, respectively; however, no S. japonicum infections were identified in snails. Moreover, a total of 305 wild feces were tested for S. japonicum infections, and no egg-positives were identified.
Conclusions: The schistosomiasis elimination achievement have been consolidated in Zhejiang Province; however, the risk factors of re-emerging schistosomiasis have not been completely eliminated, such as residual snails and imported schistosomiasis cases. Further surveillance and control activities of snails and the source of S. japonicum infections should be reinforced.
［摘要］ 目的 分析浙江省国家血吸虫病监测点疫情, 为制定新监测方案、巩固消除成果提供参考依据。方法 2015—2019年, 浙江省在血吸虫病历史流行区设立54~55个国家监测点、在6个地区设立风险监测点, 开展血吸虫病病情、钉螺 分布、野粪等疫情和风险因素监测, 对监测结果进行描述性分析。结果 2015—2019年, 浙江省国家血吸虫病监测点累 计开展本地人群血清学筛查34 530人·次, 血检阳性率为0.29%~0.68%, 未发现病原学检查阳性者; 累计开展流动人群 血清学筛查62 086人·次, 血检阳性率为0.32%~0.56%, 共发现血吸虫感染者27例 (均为输入性病例, 其中3例为埃及血 吸虫病病例、1例为急性日本血吸虫病病例), 流动人群血吸虫校正感染率为0.01%~0.07%; 累计筛查家畜829头, 未发现 血吸虫感染阳性家畜; 在固定监测点累计发现有螺面积10.55 hm2, 未发现血吸虫感染性钉螺。在风险监测点累计发现有 螺面积2.89 hm2, 未发现血吸虫感染性钉螺; 累计检查各类野粪305份, 未发现血吸虫感染阳性。结论 浙江省血吸虫病 消除成果巩固, 但残存钉螺、输入性病例等血吸虫病重新传播流行的风险因素仍未彻底消除。今后仍须进一步加强螺情 和输入性传染源的监测和防控力度。.
Keywords: Imported case; Oncomelania snail; Schistosomiasis; Surveillance; Zhejiang Province.