ABSTRACT
Chengdu-Chongqing economic circle is centered on Chengdu City and Chongqing Municipality, with aims to build the “fourth growth pole” of China’s economy. During this circle, elimination of schistosomiasis had been achieved in 82.5% of the endemic counties (districts) of Sichuan Province, and schistosomiasis is not historically endemic in Chongqing Municipality; however, there is still a risk of schistosmiasis transmission in Sichuan Province and Chongqing Municipality because the natural and social factors affecting schistosomiasis transmission have not been completely eliminated in these areas. Based on the endemic situation of schistosomiasis in Sichuan Province and Chongqing Municipality, we analyzed the opportunities and challenges of schistosomiasis control during the construction of Chengdu-Chongqing economic circle, and proposed the corresponding suggestions, so as to provide insights into the sustainable development of schistosomiasis control in the context of the Chengdu-Chongqing economic circle construction.
ABSTRACT
Objective To understand the current distribution of Oncomelania snails in Sichuan Province, so as to provide scientific evidence for formulating the schistosomiasis elimination strategy and implementing the precision schistosomiasis control measures in the province. Methods According to the National Scheme on Oncomelania hupensis Snails in China and the Scheme on Oncomelania hupensis Snails in Sichuan Province, snail surveys were performed in current snail habitats, historical snail habitats and suspected snail habitats using systematic sampling in Sichuan Province from 2016 to 2017, and the survey results were analyzed. Results From 2016 to 2017, a total of 88 346 settings were surveyed in schistosomiasis-endemic areas of Sichuan Province, and 19 314 settings were detected with snails, covering an area of 4 829.25 hm2, with no Schistosoma japonicum infection identified in snails. A total of 3 017 915 frames were investigated in Sichuan Province, and 1 041 417 frames were found to have living snails, with totally 1 791 115 living snails captured. The mean density of living snails was 0.59 snails/0.1 m2, and the mean percentage of frames with living snails was 34.51% in Sichuan Province. The current snail habitats were mainly distributed in 1 704 villages, 377 townships, 54 counties (districts) of 9 cities (prefectures) across the schistosomiasis-endemic areas of Sichuan Province. Snail habitats were mainly found in ditches (70.22%), and weeds were the predominant vegetation in snail habitats (66.45%). Snails were firstly discovered in Sichuan Province in 1913, and S. japonicum-infected snails were firstly identified in 1956, with the latest identification of S. japonicum-infected snails in 2008. Conclusion There are many settings suitable for snail breeding in Sichuan Province, and snail monitoring and control should be intensified in the future.
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
Transmission control and interruption of schistosomiasis has been gradually achieved in the mountainous and hilly endemic areas with the implementation of the schistosomiasis control programmes, which are moving towards the progress of schistosomiasis elimination. As an important measure of schistosomiasis control, health education is experiencing new challenges and problems in the new situation, and conventional health education of schistosomiasis control has already failed to meet the needs of socioeconomic and cultural development and the increasing changes of human production and life styles in the endemic areas. Therefore, a precision health education model for schistosomiasis control is of great need to be established to highly effectively promote the implementation of schistosomiasis control measures. This review summarizes the important role of health education in schistosomiasis control in mountainous and hilly endemic areas, and describes the new health education model based on optimization of the policy environment and creation of the community atmosphere according to the changes in the endemic situation of schistosomiasis and requirements of the schistosomiasis control target, so as to promote the precision and sustainable implementation of health education and health promotion in schistosomiasis control.
ABSTRACT
Objective To understand the current distribution of Oncomelania snails in Sichuan Province, so as to provide scientific evidence for formulating the schistosomiasis elimination strategy and implementing the precision schistosomiasis control measures in the province. Methods According to the National Scheme on Oncomelania hupensis Snails in China and the Scheme on Oncomelania hupensis Snails in Sichuan Province, snail surveys were performed in current snail habitats, historical snail habitats and suspected snail habitats using systematic sampling in Sichuan Province from 2016 to 2017, and the survey results were analyzed. Results From 2016 to 2017, a total of 88 346 settings were surveyed in schistosomiasis-endemic areas of Sichuan Province, and 19 314 settings were detected with snails, covering an area of 4 829.25 hm2, with no Schistosoma japonicum infection identified in snails. A total of 3 017 915 frames were investigated in Sichuan Province, and 1 041 417 frames were found to have living snails, with totally 1 791 115 living snails captured. The mean density of living snails was 0.59 snails/0.1 m2, and the mean percentage of frames with living snails was 34.51% in Sichuan Province. The current snail habitats were mainly distributed in 1 704 villages, 377 townships, 54 counties (districts) of 9 cities (prefectures) across the schistosomiasis-endemic areas of Sichuan Province. Snail habitats were mainly found in ditches (70.22%), and weeds were the predominant vegetation in snail habitats (66.45%). Snails were firstly discovered in Sichuan Province in 1913, and S. japonicum-infected snails were firstly identified in 1956, with the latest identification of S. japonicum-infected snails in 2008. Conclusion There are many settings suitable for snail breeding in Sichuan Province, and snail monitoring and control should be intensified in the future.
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
Transmission control and interruption of schistosomiasis has been gradually achieved in the mountainous and hilly endemic areas with the implementation of the schistosomiasis control programmes, which are moving towards the progress of schistosomiasis elimination. As an important measure of schistosomiasis control, health education is experiencing new challenges and problems in the new situation, and conventional health education of schistosomiasis control has already failed to meet the needs of socioeconomic and cultural development and the increasing changes of human production and life styles in the endemic areas. Therefore, a precision health education model for schistosomiasis control is of great need to be established to highly effectively promote the implementation of schistosomiasis control measures. This review summarizes the important role of health education in schistosomiasis control in mountainous and hilly endemic areas, and describes the new health education model based on optimization of the policy environment and creation of the community atmosphere according to the changes in the endemic situation of schistosomiasis and requirements of the schistosomiasis control target, so as to promote the precision and sustainable implementation of health education and health promotion in schistosomiasis control.
ABSTRACT
<p><b>OBJECTIVE</b>To use a mathematical model and computer simulation to study transmission dynamics and control of schistosomiasis in mountainous regions of Sichuan.</p><p><b>METHODS</b>Based on studies of schistosomiasis japonica transmission in 20 villages in mountainous regions of Sichuan, a mathematical model was developed to characterize the impact of local environmental factors on transmission intensity. The model integrated site-specific factors and was calibrated to field epidemiological data from 3 subset villages. The dichotomic method was then used to predict different control measures.</p><p><b>RESULTS</b>The study showed high variations in prevalence of infection and infection intensity across villages, ranging between 3%-73%, 0.1-100 epg (eggs per gram stool), respectively. Important factors including occupation of local residents, exposure to contaminated water, microclimatic characteristics were integrated in the model. The predictions of dichotomic models showed that continuing chemotherapy (coverage between 50%-60%) could reduce infection intensities to 30%-80%, but could not change local transmission potential; therefore, the termination of chemotherapy would be followed by bouncing back of transmission. Sustaining targeted environmental interventions through snail and parasite oval control at certain coverage (30%-50%, respectively) could reduce the transmission to relatively stable levels. The model predictions showed that an integrated control (e.g., including both chemotherapy and environmental interventions) could suppress the transmission to an undetectable level even interruption of transmission between 5-10 years.</p><p><b>CONCLUSION</b>The study demonstrated the feasibility of using a dynamic model, calibrated to local data, to gain insights into complicated processes underlying the transmission and informing site-specific control strategies.</p>