ABSTRACT
Objective To investigate the effects of nitroquine on the development of different stages of Plasmodium yoelii in Anopheles stephensi. Methods An. stephensi mosquitoes were fed with conventional sucrose water or sucrose water containing 100 μmol/L nitroquine one day prior to P. yoelii infection. Following starvation for 24 hours, mosquitoes were fed with the blood of Kunming mice infected with P. yoelii, and the number of oocysts was observed in the stomach of An. stephensi. After 6 days and 14 days of infection, the mosquitoes were starved for 24 hours, and then fed with conventional sucrose water or nitroquine treated sucrose water. The An. stephensi mosquitoes were starved for 24 hours 6 and 14 days post-infection with P. yoelii, and then fed with conventional sucrose water or nitroquine-containing sucrose water, the numbers of P. yoelii sporozoites were examined in the hemolymph and salivary glands of An. stephensi. Results Following exposure to nitroquine-containing sucrose water one day prior to P. yoelii infections, the number of P. yoelii oocysts was significantly lower in the An. stephensi stomach on day 7 (119.2 ± 16.1 vs. 207.3 ± 21.8; t = 3.207, P < 0.05). After conventional sucrose water was ceased for 24 hours on day 6, and An. stephensi was fed with nitroquine-containing sucrose water, the number of P. yoelii sporozoites peaked in the hemolymph on day 14 in the nitroquine treatment group (952.3 ± 22.7) and on day 12 in the sucrose water treatment group (1 287.0 ± 39.0), and there was a significant difference in the number of sporozoites in the salivary glands between the nitroquine treatment group and the sucrose water treatment group (9 467.0 ± 1 304.0 vs. 10 533.0 ± 758.7; t = 0.707, P = 0.506) on day 17. After conventional sucrose water was ceased for 24 hours on day 14, and An. stephensi was fed with nitroquine-containing sucrose water, the number of sporozoites in the salivary glands was significantly greater in the nitroquine treatment group than in the sucrose water treatment group (21 900.0 ± 2 613.0 vs. 10 533.0 ± 732.3; t = 4.188, P < 0.05). Conclusions Nitroquine treatment exhibits diverse effects the development of different stages of P. yoelii, and nitroquine treatment may reduce the transmission of P. yoelii in uninfected An. stephensi.
ABSTRACT
Since 2015 when the transmission of schistosomiasis was controlled in China, the country has been moving towards elimination of schistosomiasis, with the surveillance-response as the main interventions for schistosomiasis control. During the period of the 13th Five-Year Plan, the transmission of schistosomiasis had been interrupted in four provinces of Sichuan, Jiangsu, Yunnan and Hubei and the prevalence of schistosomiasis has been at the historically lowest level in China. As a consequence, the goal set in The 13th Five-Year National Schistosomiasis Control Program in China is almost achieved. However, there are multiple challenges during the stage moving towards elimination of schistosomiasis in China, including the widespread distribution of intermediate host snails and complicated snail habitats, many types of sources of Schistosoma japonicum infections and difficulty in management of bovines and sheep, unmet requirements for the current schistosomiasis control program with the currently available tools, and vulnerable control achievements. During the 14th Five-Year period, it is crucial to consolidate the schistosomiasis control achievements and gradually solve the above difficulties, and critical to provide the basis for achieving the ultimate goal of elimination of schistosomiasis in China. Based on the past experiences from the national schistosomiasis control program and the challenges for schistosomiasis elimination in China, an expert consensus has been reached pertaining to the objectives, control strategy and measures for The 14th Five-Year National Schistosomiasis Control Program in China, so as to provide insights in to the development of The 14th Five-Year National Schistosomiasis Control Program in China.
ABSTRACT
Objective To compare the effectiveness of loop-mediated isothermal amplification (LAMP) assay and microscopic examinations for detection of Schistosoma japonicum infections in Oncomelania hupensis in transmission-interrupted regions, so as to provide insights into the optimization of snail surveillance tools in these regions. Methods Four hilly schistosomiasis-endemic villages where transmission interruption was achieved were selected in Heqing County of Yunnan Province as the study villages, including Xinzhuang and Gule villages in hilly regions and Lianyi and Yitou villages in dam regions. Snail survey was performed by means of systematic sampling combined with environmental sampling in July 2018. All captured snails were identified for S. japonicum infections using microscopy. In addition, 10 to 20 snails were randomly sampled from each snail habitat following microscopy, numbered according to environments and subjected to LAMP assay. The positive rate of settings with S. japonicum-infected snails was compared among villages. Results A total of 7 949 living snails were captured from 83 snail habitats in 4 villages, and no S. japonicum infection was detected in snails. There were 226 mixed samples containing 1 786 snails subjected to LAMP assay, and positive LAMP assay was found in 3 mixed samples from 3 snail habitats in 2 dam villages. The positive rates of settings with S. japonicum-infected snails were comparable between Lianyi Village (one setting) and Yitou Village (2 set tings) (5.89% vs. 14.29%, P = 0.344). However, the overall positive rate of settings with S. japonicum-infected snails was significantly higher in dam villages (9.67%, 3/31) than in hilly villages (0) (P = 0.048). Conclusions LAMP assay is more sensitive to detect S. japonicum infections in O. hupensis than conventional microcopy method, which may serve as a supplementary method for detection of S. japonicum infections in O. hupensis in high-risk snail habitats in hilly transmission-interrupted regions.
ABSTRACT
Schistosomiasis was once hyper-endemic in Jiangsu Province. During the past seven decades, the professionals working in schistosomiasis control from Jiangsu Province insisted on scientific and precision control all the time, created a series of replicable and generalizable “Jiangsu experiences”. These practices have developed a number of tools and approaches that have been employed in schistosomiasis control programs in main endemic foci of China. More importantly, the successful experiences from national schistosomiasis control programs of China have been firstly transferred to Africa by professionals from Jiangsu Province, and remarkable achievements have been obtained for the control of schistosomiasis haematobia in Zanzibar.
ABSTRACT
Schistosomiasis was once heavily endemic in Jiangsu Province. Following the control efforts for several decades, schistosomiasis was almost eradicated in all endemic counties in Jiangsu Province in 1980, and transmission control was achieved in the province in 2011. According to the principle of “implementing the control measures with adaptation to local circumstances and guiding the control programs with classified interventions”, an integrated strategy with emphasis on the management of both infectious sources and snails has been recently employed for schitsosomiasis control in Jiangsu Province. In addition, a sensitive and highly effective surveillance system has been built and the application of novel techniques and information construction has been intensified to effectively interrupt the transmission of schistosomiasis in the Province. Transmission interruption of schistosomiasis was achieved in all endemic counties in Jiangsu Province. The paper summarizes the endemic situation of schistosomiasis, progress of schistosomiasis control, and major schistosomiasis control measures implemented during the stage of transmission interruption in Jiangsu Province.
ABSTRACT
Schistosomiasis was once hyper-endemic in Jiangsu Province. During the past seven decades, the professionals working in schistosomiasis control from Jiangsu Province insisted on scientific and precision control all the time, created a series of replicable and generalizable “Jiangsu experiences”. These practices have developed a number of tools and approaches that have been employed in schistosomiasis control programs in main endemic foci of China. More importantly, the successful experiences from national schistosomiasis control programs of China have been firstly transferred to Africa by professionals from Jiangsu Province, and remarkable achievements have been obtained for the control of schistosomiasis haematobia in Zanzibar.
ABSTRACT
Objective To understand the strategy of schistosomiasis elimination and its effects in Jinhu County, Jiangsu Province. Methods The data of schistosomiasis control in Jinhu County at different stages from 1970 to 2017 were collected and analyzed. Results From 1970 to 2017, there were three stages of schistosomiasis control, including transmission control, transmission interruption, and monitoring and elimination stages in Jinhu County. The main measures included Oncomelania hupensis snail control, infectious source control, and health education. A total of area of 290 691.78 hm2 was detected in Jinhu County, and the area with snails was 3 420.98 hm2. There were 8 729.37 hm2 area with snails was controlled. Since 2014, no O. hupensis snails were found. A total of 525 377 person-times were examined for schistosomiasis, with 2 815 schistosomiasis patients identified, and 2 844 person-times were treated by chemotherapy. In addition, 977 cases received the expand chemotherapy. Since 1990, no local schistosome-infected persons were found. In 2017, the awareness rate of schistosomiasis control knowledge and the correct rate of health behavior were increased by 54.59% and 14.23% respectively compared with those in 1992. Conclusions The comprehensive schistosomiasis control measures implemented in Jinhu County at different periods have achieved remarkable outputs and accelerated the schistosomiasis elimination process. However, the precise control measures should be implemented in the future to consolidate the prevention and control achievements.
ABSTRACT
Objective To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. Methods The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. Results From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. Conclusions The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.
ABSTRACT
In China, the mountainous and hilly schistosomiasis-endemic areas are mainly distributed in 2 provinces of Sichuan and Yunnan. Although great success has been achieved in schistosomiasis control in mountainous and hilly areas, there is a risk of re-emerging schistosomiasis in local areas. Hereby, we described the emergency treatment of two schistosomiasis outbreaks that occurred in transmission-interrupted areas of Yunnan Province in 2011 and 2013, pointed out the risk of schistosomiasis rebounding in mountainous and hilly areas and proposed some suggestions.
ABSTRACT
Objective To explore the integrated schistosomiasis control model in mountainous and hilly endemic regions, so as to provide insights into the development of the schistosomiasis elimination strategy. Methods Five hilly and mountainous areas endemic for schistosomiasis were selected as the integrated control demonstration areas in Sichuan Province from 2011 to 2015. According to the epidemic characteristics, economic levels and overall development planning of the demonstration areas, the goals, strategies and measures were developed, and the effectiveness of schistosomiasis control was evaluated following implementation of the integrated control. Results The support system of the integrated schistosomiasis control model was built in the integrated control demonstration areas in Sichuan Province from 2011 to 2015, and five ecological, industrialized and sustainable development models of integrated schistosomiasis control were developed, including integration of balancing rural and urban development, systematic ecological improvement, intensified ecological agriculture, scientific management and health education of schistosomiasis control and ecological ethnic circular economy. Since the implementation of the integrated schistosomiasis control model, the snail habitats were completely changed. Until 2015, 92.0% of all historical areas with snails were managed, the coverage of safe drinking water was 100.0%, and more than 95.0% of the livestock were fenced. The coverage of sanitary toilets increased by 93.0%, 96.8%, 78.8%, 87.1% and 82.0% from 2011 to 2015, respectively, and the farmers’mean yearly income increased by 32.7% in the demonstration areas. From 2011 to 2015, the seroprevalence of human Schistosoma japonicum infections reduced from 3.1% in 2011 to 1.6% in 2015 in the demonstration areas, and no egg-positives were identified. In addition, the number of fenced bovines reduced year by year, and no egg-positives were detected. The areas of snail habitats were 398.7, 108.2 hm2 and 52.9 hm2 in the demonstration areas from 2011 to 2013, with no infected snails found, and no snails were detected since 2014. The awareness of schistosomiasis control knowledge and percentage of correct behavior formation increased year by year among residents in the demonstration areas from 2011 to 2015. Conclusions The five integrated schistosomiasis control models meet the needs of the current schistosomiasis control activities in mountainous and hilly endemic areas of Sichuan Province, and achieve the goals of controlling the sources of S. japonicum infections, economic development, social progress and improving the ecological environment, which provides new insights into schistosomiasis elimination in the country.
ABSTRACT
Schistosomiasis is an old and geographically widespread parasitic disease that severely damages human health and affects socioeconomic development in China. The implementation of the integrated strategy with emphasis on controlling the source of Schistosoma japonicum infection and the National Mid- and Long-Term Plan for Schistosomiasis Prevention and Control (2004–2015) in China greatly facilitated the progress towards the elimination of schistosomiasis in China. Since transmission control of schistosomiasis was achieved in 2015, the goal of the national schistosomiasis control program has moved to transmission interruption and elimination in China. Because of the impacts of natural and social factors, and the new situation, new task and new demands following the continuous decline in the endemic situation of schistosomiasis, several challenges exist to achieve the goal of schistosomiasis elimination nationwide. This paper analyzed the current endemic status of schistosomiasis, progress and challenges of schistosomiasis elimination, and proposed some suggestions for the national chistosomiasis elimination program in China.
ABSTRACT
Schistosomiasis was once heavily endemic in Jiangsu Province. Following the control efforts for several decades, schistosomiasis was almost eradicated in all endemic counties in Jiangsu Province in 1980, and transmission control was achieved in the province in 2011. According to the principle of “implementing the control measures with adaptation to local circumstances and guiding the control programs with classified interventions”, an integrated strategy with emphasis on the management of both infectious sources and snails has been recently employed for schitsosomiasis control in Jiangsu Province. In addition, a sensitive and highly effective surveillance system has been built and the application of novel techniques and information construction has been intensified to effectively interrupt the transmission of schistosomiasis in the Province. Transmission interruption of schistosomiasis was achieved in all endemic counties in Jiangsu Province. The paper summarizes the endemic situation of schistosomiasis, progress of schistosomiasis control, and major schistosomiasis control measures implemented during the stage of transmission interruption in Jiangsu Province.
ABSTRACT
Objective To understand the strategy of schistosomiasis elimination and its effects in Jinhu County, Jiangsu Province. Methods The data of schistosomiasis control in Jinhu County at different stages from 1970 to 2017 were collected and analyzed. Results From 1970 to 2017, there were three stages of schistosomiasis control, including transmission control, transmission interruption, and monitoring and elimination stages in Jinhu County. The main measures included Oncomelania hupensis snail control, infectious source control, and health education. A total of area of 290 691.78 hm2 was detected in Jinhu County, and the area with snails was 3 420.98 hm2. There were 8 729.37 hm2 area with snails was controlled. Since 2014, no O. hupensis snails were found. A total of 525 377 person-times were examined for schistosomiasis, with 2 815 schistosomiasis patients identified, and 2 844 person-times were treated by chemotherapy. In addition, 977 cases received the expand chemotherapy. Since 1990, no local schistosome-infected persons were found. In 2017, the awareness rate of schistosomiasis control knowledge and the correct rate of health behavior were increased by 54.59% and 14.23% respectively compared with those in 1992. Conclusions The comprehensive schistosomiasis control measures implemented in Jinhu County at different periods have achieved remarkable outputs and accelerated the schistosomiasis elimination process. However, the precise control measures should be implemented in the future to consolidate the prevention and control achievements.
ABSTRACT
Objective To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. Methods The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. Results From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. Conclusions The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.
ABSTRACT
In China, the mountainous and hilly schistosomiasis-endemic areas are mainly distributed in 2 provinces of Sichuan and Yunnan. Although great success has been achieved in schistosomiasis control in mountainous and hilly areas, there is a risk of re-emerging schistosomiasis in local areas. Hereby, we described the emergency treatment of two schistosomiasis outbreaks that occurred in transmission-interrupted areas of Yunnan Province in 2011 and 2013, pointed out the risk of schistosomiasis rebounding in mountainous and hilly areas and proposed some suggestions.
ABSTRACT
Objective To explore the integrated schistosomiasis control model in mountainous and hilly endemic regions, so as to provide insights into the development of the schistosomiasis elimination strategy. Methods Five hilly and mountainous areas endemic for schistosomiasis were selected as the integrated control demonstration areas in Sichuan Province from 2011 to 2015. According to the epidemic characteristics, economic levels and overall development planning of the demonstration areas, the goals, strategies and measures were developed, and the effectiveness of schistosomiasis control was evaluated following implementation of the integrated control. Results The support system of the integrated schistosomiasis control model was built in the integrated control demonstration areas in Sichuan Province from 2011 to 2015, and five ecological, industrialized and sustainable development models of integrated schistosomiasis control were developed, including integration of balancing rural and urban development, systematic ecological improvement, intensified ecological agriculture, scientific management and health education of schistosomiasis control and ecological ethnic circular economy. Since the implementation of the integrated schistosomiasis control model, the snail habitats were completely changed. Until 2015, 92.0% of all historical areas with snails were managed, the coverage of safe drinking water was 100.0%, and more than 95.0% of the livestock were fenced. The coverage of sanitary toilets increased by 93.0%, 96.8%, 78.8%, 87.1% and 82.0% from 2011 to 2015, respectively, and the farmers’mean yearly income increased by 32.7% in the demonstration areas. From 2011 to 2015, the seroprevalence of human Schistosoma japonicum infections reduced from 3.1% in 2011 to 1.6% in 2015 in the demonstration areas, and no egg-positives were identified. In addition, the number of fenced bovines reduced year by year, and no egg-positives were detected. The areas of snail habitats were 398.7, 108.2 hm2 and 52.9 hm2 in the demonstration areas from 2011 to 2013, with no infected snails found, and no snails were detected since 2014. The awareness of schistosomiasis control knowledge and percentage of correct behavior formation increased year by year among residents in the demonstration areas from 2011 to 2015. Conclusions The five integrated schistosomiasis control models meet the needs of the current schistosomiasis control activities in mountainous and hilly endemic areas of Sichuan Province, and achieve the goals of controlling the sources of S. japonicum infections, economic development, social progress and improving the ecological environment, which provides new insights into schistosomiasis elimination in the country.
ABSTRACT
Schistosomiasis is an old and geographically widespread parasitic disease that severely damages human health and affects socioeconomic development in China. The implementation of the integrated strategy with emphasis on controlling the source of Schistosoma japonicum infection and the National Mid- and Long-Term Plan for Schistosomiasis Prevention and Control (2004–2015) in China greatly facilitated the progress towards the elimination of schistosomiasis in China. Since transmission control of schistosomiasis was achieved in 2015, the goal of the national schistosomiasis control program has moved to transmission interruption and elimination in China. Because of the impacts of natural and social factors, and the new situation, new task and new demands following the continuous decline in the endemic situation of schistosomiasis, several challenges exist to achieve the goal of schistosomiasis elimination nationwide. This paper analyzed the current endemic status of schistosomiasis, progress and challenges of schistosomiasis elimination, and proposed some suggestions for the national chistosomiasis elimination program in China.
ABSTRACT
Objective To evaluate the effects of the strategy of transmission interruption of schistosomiasis in Runzhou Dis-trict,Zhenjiang City,Jiangsu Province.Methods The comprehensive prevention and control strategy was carried out in Run-zhouDistrict,Zhenjiang City,Jiangsu Province.The strategy was relied mainly on the Oncomelania hupensis snail control,ex-tended chemotherapy of schistosomiasis in residents and the health education.The infection rate of schistosomiasis in residents,area with snails,area with snails controlled,and the rates of awareness and correct behavior of schistosomiasis were as evalua-tion indexes.Results The area with snails controlled was 7 091.50 hm2in Runzhou District,Zhenjiang City from 2001 to 2016.The area with snails reduced year by year from 2001 to 2016.There was a negative correlation between the coverage intensity of snail control and the area with snails(r=-0.874,P=0).There were 1 703 serum positive and 199 fecal positive people of schis-tosomiasis in the permanent residents from 2001 to 2016.These serum and fecal positive people of schistosomiasis were all treat-ed with praziquantel.The serum positive rate of schistosomiasis in the permanent residents dropped to below 1.0％after 2005.The fecal positive patients were not found in 2004 and later.Totally 189 639 people received the questionnaire survey for the knowledge of schistosomiasis control from 2001 to 2016.The rates of awareness and correct behavior of schistosomiasis were raised in the residents year by year.The goal of the transmission interruption of schistosomiasis came to true in Runzhou Dis-trict,Zhenjiang City in 2016.Conclusion The comprehensive prevention and control strategy including mainly the snail con-trol,extended chemotherapy of schistosomiasis and health education could achieve the goal of transmission interruption of schis-tosomiasis in the areas of marshland along the Yangtze River.
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Objective To establish a risk assessing indicator system after the transmission interruption of schistosomiasis in Wuxi City,so as to provide evidences for formulating strategies on schistosomiasis control and prevention. Methods A primary risk assessing indicator system was established based on the literature review. Alternative indicators were scored and screened to establish a final indicator system through two rounds of Delphy method and the related normalized weights and combined weights were also calculated. Results The risk assessing indicator system was established through two rounds of expert consultation in-cluding 3 first grade indicators and 15 second grade indicators. Among the first grade indicators,the normalized weights of natu-ral environment,key populations and social environment were 0.3706,0.2929 and 0.3365,respectively. Among the second grade indicators,the migrant population accounted for the highest combined weight of 0.1252 compared to domestic animal of 0.0371. The authority degree among the first grade indicators was between 0.91 and 0.93,while the authority degree among the second grade indicators was between 0.79 and 0.92. Conclusion The scientific and authoritative risk assessing indicator sys-tem after the transmission interruption of schistosomiasis is established,which provides the evidences for risk assessment on schistosomiasis transmission in Wuxi City.
ABSTRACT
Objective To study the effect of schistosomiasis transmission interruption model based on intensive agriculture in hilly endemic areas,so as to provide the reference for the similar endemic areas. Methods Based on the development of in-tensive agriculture in Guanghan City,a comprehensive demonstration area of schistosomiasis control with measures such as new rural construction,hardening ditches,the adjustment of industrial structure and water remediation measures was constructed. Ji-nhua,Shiguan and Hongyan villages were chosen as the evaluation sites to comparatively analyze the indexes of intensive agri-culture and schistosomiasis control effects. Results Compared with the demonstration area before construction,in 2014,the harden rates of ditches and village roads were increased by 49.57％and 39.33％respectively;and the proportion of agricultural machinery increased by 25％. The positive rate of serological tests of schistosomiasis was decreased by 81.74％. The Oncomela-nia hupensis snail area was decreased from 2.44 hm2(2007)to 0(2014). The awareness rate of schistosomiasis control knowl-edge and correct behavior rate of the residents were increased from 51.28％ and 90.85％ to 91.29％ and 97.69％ respectively. The experience of the demonstration area ensured the entire Guanghan District achieved the schistosomiasis transmission inter-ruption criterion at the end of 2014. Conclusions The schistosomiasis control model of intensive agriculture combined with oth-er comprehensive measures has a good effect on interrupting the endemic of schistosomiasis,and it can realize the sustainable development of the agricultural economy and schistosomiasis control.