Assessment of schistosomiasis transmission risk in Nanjian County of Yunnan Province in 2019 / 中国血吸虫病防治杂志

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.

Distribution features of wild feces in schistosomiasis endemic areas in Jian-gling County,Hubei Province / 中国血吸虫病防治杂志

Objective To understand the spatial distribution characteristics of wild feces in schistosomiasis endemic areas of Jiangling County,Hubei Province and further explore the source of infection efficiently,so as to provide the evidence for the development of corresponding monitoring and response technology. Methods In 2011,the fresh wild feces were investigated every two months in the selected 15 villages by the severity of historical endemic in Jiangling County. The schistosome miracidi-um hatching method was used to test the schistosome infection of the wild feces. The descriptive analysis and spatial analysis were used for the description of the spatial distribution of the wild feces. Results Totally 701 wild feces samples were collected with the average density of 0.0556/100 m2,and the positive rate of the wild feces was 11.70%(82/701). The results of the re-gression analysis showed a positive spatial correlation between the positive rate of wild feces and the rate of human infection,the area with infected Oncomelania hupensis and the number of fenced cattle,and the corrected R2 of the model was 0.58. Conclu-sion The infection rate of wild feces is positively correlated with the rate of human infection,area with infected O. hupensis and number of fenced cattle in space in Jiangling County,so the prevention and control measures could be conducted according to the spatial distribution of the positive wild feces.

Effect of wild feces detection in Oncomelania hupensis environments on sur-veillance of infection source of schistosomiasis / 中国血吸虫病防治杂志

Objective To evaluate the effect of wild feces detection in Oncomelania hupensis environments on the surveil?lance of infection source of schistosomiasis,and find the weakness in schistosomiasis control in Hubei Province,so as to put for?ward the targeted strategies and measures. Methods Four environments with O. hupensis snails in endemic areas of Hubei Provinces,where human and livestock often haunted,were selected according to the river systems,namely the Juzhanghe River beach in Jingzhou City,Changjiang River beach in Jiayu County,Hanbei River beach in Tianmen City,and Changshou River beach in Zhongxiang City,then the snail survey and wild feces detection were implemented in the selected environments. Re?sults There were O. hupensis snails,livestock,wild feces of cattle or sheep as well as positive cattle feces found in all the 4 environments,and the positive rate of schistosome miracidium incubation was 47.62%. Conclusion The schistosome miracidi?um positive rate of wild feces of cattle is high in the environments with snails in endemic areas of Hubei Province ,which has high risk for schistosomiasis transmission.

Surveillance and risk assessment system of schistosomiasis in Jiangsu Prov-inceⅢRisk of schistosomiasis transmission in the area along the Yangtze River in Yang-zhou City / 中国血吸虫病防治杂志

Objective To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City,so as to provide evidences for establishing a post?transmission surveillance system for schistosomiasis in marsh?land regions. Methods The water infectivity,floating boatmen and fishermen infection,reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City,including Guangling,Hanji?ang,Jiangdu,Yizheng and Development Zone,and the transmission factors and risky characteristics were assessed after inter?ruption of schistosomiasis transmission in marshland regions. Results A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed,after breeding,their overall sur?vival rate was 99.33%;1 490 were dissected,with no schistosome infection. Of the 5 576 floating boatmen and fishermen exam?ined,no schistosome infection was observed,and among the 3 566 domestic animals(including 171 cattle,1 895 sheep and 1 500 pigs),no infections were detected. During the period between January and March,2016,there were 3 200 mouse traps placed on 8 marshlands,and 62 wild mice were captured from 6 marshlands,with a capture rate of 1.94%,and no schistosome?infected wild mice were seen. In addition,there were 35 pieces of fresh wild feces captured from 7 marshlands,including 11 pieces of bovine feces(31.43%),17 pieces of sheep feces(48.57%),2 pieces of dog feces(5.71%)and 5 pieces of other feces (14.29%),and no infections were detected. Conclusions There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However,the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.

Investigation of wild feces pollution in schistosomiasis endemic areas in Yun-nan Province / 中国血吸虫病防治杂志

Objectives To understand the status of wild feces distribution and pollution in schistosomiasis endemic areas in Yunnan Province. Methods According to the distribution of Oncomelania hupensis snails and characteristics of human and ani-mal activities in recent five years 6 schistosomiasis endemic villages in Weishan Nanjian and Midu counties 2 villages each county were selected as the investigated areas and more than 4 hm2 area with snails around each village were investigated for the types and densities of wild feces. The schistosome infested feces was detected with the hatching method. Results Totally 63 hm2 were investigated and 420 wild feces were found in all kinds of environments. The densities of wild feces were 0.066 7 piles/100 m2 and the densities of wild feces of the road and the hillside were the highest 0.098 7 piles/100 m2 and 0.088 0 piles/100 m2 respectively . Totally 260 fresh wild feces were collected including the feces of human being cattle horse dog sheep and pig and the feces of cattle and dog was the most 37.38%and 30.71% respectively . No schistosome positive feces was found. Conclusions There are a lot of wild feces in snail areas in Yunnan Province and the risk of schistosomiasis transmission is still high. Therefore we should strengthen the banning grazing measures and the investigation of dogs.