[Experience and insights of schistosomiasis elimination in Yujiang County of Jiangxi Province-Commemoration of the 60th anniversary of publishing Chairman Mao Zedong's two poems"Farewell to the God of Plague"].

Schistosomiasis is one of the major infectious diseases that seriously endanger the health of people, and social and economic development. Before the year of 1949, Yujiang County of Jiangxi Province was one of hyper-endemic regions for schistosomiasis. After the founding of the People's Republic of China, under the leadership and high attention of the Chinese Communist Party and the government, after the arduous struggle with schistosomiasis, Yujiang County became the first county that reached the standard of eradication of schistosomiasis in 1958. Moreover, Chairman Mao Zedong gladly wrote the famous poem of "Farewell to the God of Plague". Since then, the work of schistosomiasis control has been greatly inspired by the poem. In 2016, Yujiang County became the first county of schistosomiasis elimination in Jiangxi Province. In this paper, the experience and process of eradication and elimination of schistosomiasis in Yujiang County are systematically reviewed and summarized by analyzing the endemic situation of schistosomiasis before and after the eradication and elimination in Yujiang County, to expound the significance and enlightenment of the schistosomiasis control in Yujiang County. This paper commemorates the 60th anniversary of the publication of Mao Zedong's poem.

[Study on distribution status of Oncomelania hupensis, the intermediate host of Schistosoma japonicum in Jiangxi Province â ¡ Spatial-temporal distribution of snail-infested environments].

OBJECTIVE: To grasp the status of Oncomelania hupensis snail-infested environments in schistosomiasis endemic areas of Jiangxi Province, and establish the spatial database of snail-infested environments with the administrative village as the unit. METHODS: The spatial and temporal distributions of the historical snail environments, existing snail environments, and suspicious snail-infested environments were analyzed by the historical data review and field investigations. RESULTS: The distribution of snail-infested environments in Jiangxi Province included two popular types of lakeshore and hills. The O. hupensis snail-infested environments were mainly concentrated in the Poyang Lake area, which accounting for 66.97% of the total snail-infested areas. The potential snail-infested environment area was 204 745.48 hm2, among which the potential snail-infested environment areas in the lakeshore and hills were 146 548.58 hm2 and 58 196.90 hm2, accounting for 71.58% and 28.42%, respectively. The real existing snail area was 83 234.50 hm2, among which the real existing snail areas in the lakeshore and hills were 80 890.81 hm2 and 2 343.69 hm2, accounting for 97.18% and 2.82%, respectively. The compressed snail area was 114 253.30 hm2 with a compression rate of 57.85%, of which the compression rates in the lakeshore and hills were 46.51% and 94.97%, respectively. In the four types of snail-infested environments, the areas of Type I, Type II, Type III and Type IV accounted for 55.77%, 25.75%, 13.91% and 4.57% of the total area, respectively. CONCLUSIONS: The spatial database of O. hupensis snail-infested environments is established comprehensively and systematically, that will be conducive to tracking and performing the dynamic updates of the data of snails, so as to provide an important technical support for investigation and monitoring in the future.

[Challenges and countermeasures of schistosomiasis elimination in Jiangxi Province].

Jiangxi Province was once one of schistosomiasis heavy endemic provinces in China. Thanks for more than 60 years' unremitting effort, great achievements have been obtained in schistosomiasis control in this province. This paper reviews the control history of schistosomiasis, and demonstrates the current epidemic situation of the disease in Jiangxi Province, and its contribution to national schistosomiasis control achievements. The difficulties and challenges of schistosomiasis elimination in this province are analyzed and the countermeasures are also put forward accordingly.

[Study on distribution status of Oncomelania hupensis - intermediate host of Schistosoma japonicum in Jiangxi Province I Analysis of distribution of O. hupensis in Poyang Lake area].

OBJECTIVE: To grasp the distribution status of Oncomelania hupensis snails in Poyang Lake area, so as to provide the evidence for formulating and adjusting the schistosomiasis prevention and control strategy in lake areas. METHODS: The vector grid was created and sampled randomly by 200 m × 200 m in the spatial database of grassland, and the distribution of snails was investigated in the selected grid by using the method of mechanical sampling by 50 m × 50 m. At the same time, the elevation of investigation points was extracted based on the topographic map of Poyang Lake. RESULTS: Totally 949 and 210 investigation points were collected from the south and north of Poyang Lake areas, accounting for 3.04% and 3.21% of all the investigation points in the respective region. The number of investigation points, the appearance rate of snail frame, and the average density of alive snails were 15 231, 8.15%, and 0.463/0.1 m2, respectively. The elevation of snail distribution area of the south and north Poyang Lake areas were 11-16 m and 9-16 m respectively. The elevation of concentrated snail belts of the south Poyang Lake area were 12-13 m and 15-16 m, and the elevation of concentrated snail belts of the north Poyang Lake area was 12-14 m. CONCLUSIONS: The distribution of snails is in the range of 9-16 m. The suitable habitats of snail breeding are moving from the south Poyang Lake area to the north Poyang Lake area, and from high elevation to low elevation. In the future, the schistosomiasis prevention and control measures could be formulated based on the geographical characteristics of current snail distribution in order to consolidate the achievements of schistosomiasis control.

[Role of new strategy in transmission control of schistosomiasis in Poyang Lake region].

OBJECTIVE: To evaluate the role of new strategy in the transmission control of schistosomiasis in Poyang Lake region. METHODS: The information and epidemic data of schistosomiasis control were collected and analyzed in Poyang Lake region from 2005 to 2016. RESULTS: After eleven years of carrying out the new strategy, thirteen counties achieved the objective of transmission control in Poyang Lake region. In 2016, the number of schistosomiasis cases and human infection rate were 10 301 and 0.03%, decreased by 89.64% and 99.45% compared with those in 2005, respectively. The number of cattle and schistosome -infected cattle were 68 152 and 5, decreased by 50.84% and 99.83% compared with those in 2005, respectively. The average density of Oncomelania hupensis snails was decreased by 61.52%. No schistosome-infected snails were found since 2014. CONCLUSIONS: The new strategy accurately locates the key points and targets of schistosomiasis transmission chain, which has controlled the human and animal's fecal eggs from polluting grassland, and cut off the transmission chain, reduced both the infection rates of human and animal and the re-infection risk, and promoted to achieve the target of schistosomiasis transmission control in Poyang Lake region.

[Study on cut-off value of IHA method for schistosomiasis diagnosis in different endemic areas].

OBJECTIVE: To explore the cut-off value of the indirect haemagglutination test (IHA) method for schistosomiasis japonica diagnosis in different endemic areas. METHODS: Totally 55 nature villages of the lake-type endemic counties, Yugan and Xinzi, in Poyang Lake Region of Jiangxi Province were chosen as the study fields, and all the villagers over 5 years old were parallelly examined by Kato-Katz method + miracidial hatching test and IHA method. The detection data were analyzed by the correlation analysis, and the threshold values of the IHA method in different endemic areas were decided by the receiver operating characteristic (ROC) curve. RESULTS: The positive rate of stool examinations of the villagers was correlated with the distribution trend of the antibody level of whole population (r = 0.588, P ＜ 0.05), but no correlation with the antibody level of the positive population (r = 0.221, P ＞ 0.05). The antibody level of stool-negative population during the period of 2008 to 2011 detected by IHA method dropped year by year, and the annual difference was statistically significant (F = 3.650, P ＜ 0.05). While the antibody level of stool-positive population found during the period of 2008 to 2011 maintained a certain high level in the 4 years, and there was no statistically significant difference among them (F = 2.461, P ＞ 0.05). When the positive rates were <1%, 1%-5% or >5%, the specificity of diagnosis could be improved when 1∶80, 1∶20 and 1∶10 were used as the cut-off values of IHA correspondingly. CONCLUSIONS: The different threshold values for diagnosis of schistosomiasis japonica should be considered while using IHA method to screen out patients in different endemic areas.

[Status and future development of surveillance of schistosomiasis in Jiangxi Province].

Jiangxi Province is one of serious endemic provinces with schistosomiasis japonica in China. The transmission control of schistosomiais has been achieved in whole province in 2015 after more than 60 years' great efforts. Of them, the surveillance has played an important role in the control of schistosomiasis. Based on the comprehensive analysis of the status of schistosomiasis epidemic, surveillance and challenges, this article exports the priority and development trend of surveillance after the achievement of transmission control of schistosomiasis in Jiangxi Province.

[Status and challenges for schistosomiasis in transmission-interrupted areas in Jiangxi Province].

This report analyzes the status of schistosomiasis epidemic, surveillance and challenges in transmission-interrupted areas of Jiangxi Province. There are 24 schistosomiasis transmission interrupted counties (cities, districts) among 39 endemic counties (cities, districts). Among the 24 counties, there are 6 counties with Oncomelania hupensis snails and 461 villages endemic, with 1.29 million residents. Since 2009, there have not been acute and chronic cases of schistosomiasis and all the patients are historical advanced schistosomiasis cases. The area with snail habitats is 37.02 hm2. Since 2015, the schistosomiasis surveillance has covered the entire transmission interrupted areas. However, there are still many challenges, such as endemic instability, weak surveillance capacity, lack of surveillance awareness and other issues. Towards the schistosomiasis elimination, the surveillance should be based on the snail monitoring mainly, supplemented by the mobile population monitoring, and in addition, the capacity building, standardized report of endemic, and snail habitat reform should also be further strengthened.