Abstract: Objective　To assess the schistosomiasis transmission risk in Nanjing County, so as to provide the scientific evidence for the development of the schistosomiasis control strategy and consolidation of the control achievements. Methods　On May 2019, the Deqiu Village in Deqiu Town and Baiyun Village in Nanjing Town of Yunnan Province, where schistosomiasis were historically relatively highly endemic, were selected to assess the risk of transmission of schistosomiasis by means of a retrospective review of the data pertaining to the historical endemic situation and schistosomiasis control, combined with a cross?sectional survey of snail and wild feces distribution. Results　During the period between 2017 and 2018, the mean sero?prevalence rates of Schistosoma japonicum infections were 6.76% (202/2 990) and 2.86% (142/4 971) in humans and 0 (0/1 160) and 10.65% (31/291) in bovines in Deqiu and Baiyun villages of Nanjian County, respectively; however, no egg?positives were identified; in addition, there were 21.06 hm2 snail habitats found, but no S. japonicum infections were detected in snails. In 2019, there was 6.17 hm2 snail habitats detected, with 2.17% (245/11 298) occurrence of frames with snails and a 0.06 snails/0.1 m2 density of living snails; however, no positives for nucleic acid detection were seen in snails; among the 136 wild fecal samples captures from 23 settings, no S. japonicum infections were identified. Conclusions　The risk of schistosomiasis transmission remains at a low level in Nanjian County; however, the factors affecting the transmission of schistosomiasis have not been completed eliminated. The integrated schistosomiasis control strategy with an emphasis on the control of the source of S. japonicum infections requires to be reinforced to consolidate the control achievements.

Key words: Schistosomiasis, Oncomelania snail, Wild feces, Source of infection, Transmission risk, Nanjian County

摘要： 目的　了解云南省南涧县血吸虫病传播风险，为制定防治对策、巩固防治成果提供科学依据。方法　2019年5月，选取南涧县既往血吸虫病疫情相对较重的乐秋乡乐秋村和南涧镇白云村作为血吸虫病传播风险评估村，采用回顾性调查方法收集历史疫情和防治资料，并进行钉螺和野粪分布等现况调查，综合评估血吸虫病传播风险。结果　2017-2018年, 云南省南涧县乐秋村和白云村人群血吸虫病筛查平均血检阳性率分别为6.76%（202/2 990）和2.86%（142/4 971），牛血检阳性率分别为0（0/1 160）和10.65%（31/291），均未发现粪检阳性；现有钉螺分布面积21.06 hm2，未发现血吸虫感染性钉螺。2019年在乐秋村和白云村查出有螺面积6.17 hm2，有螺框出现率为2.17%（245/11 298），活螺平均密度为0.06只/0.1 m2（683/11 298），未发现血吸虫核酸阳性钉螺；共在23个环境捡获牛、羊、犬和马属动物等野粪136份，未发现血吸虫病原学阳性。结论　南涧县血吸虫病传播风险已处于低水平，但影响血吸虫病传播的因素仍未彻底消除。今后仍需加强以传染源控制为主的血吸虫病综合防治措施，以巩固防治成果。

关键词: 血吸虫病, 钉螺, 野粪, 传染源, 传播风险, 南涧县