Approaches being used in the national schistosomiasis elimination programme in China:a review

Schistosomiasis japonica,caused by the human blood fluke Schistosoma japonicum,remains a major public health problem in China,although great success has been achieved.The control efforts during the past half-decade,notably the wide implementation of the new integrated strategy with emphasis on control of the source of S.japonicum infection across the country since 2004,has greatly reduced S.japonicum in humans,livestock,and intermediate host Oncomelania hupensis snails,and transmission control of schistosomiasis was achieved in China in 2015.A two-stage roadmap was therefore proposed for schistosomiasis elimination in 2015,with aims to achieve transmission interruption by 2020 and achieve disease elimination by 2025 in the country.During the last two decades,a variety of approaches,which target the epidemiological factors of schistosomiasis japonica have been developed,in order to block the transmission cycle of the parasite.These approaches have been employed in the national or local schistosomiasis control activities,and facilitated,at least in part,the progress of the schistosomiasis elimination programs.Here,we present an approach to control the source of S.japonicum infection,three new tools for snail control,three approaches for detecting and monitoring S.japonicum infection,and a novel model for health education.These approaches are considered to play a great role in the stage moving towards transmission interruption and elimination of schistosomiasis in China.

A multidisciplinary,integrated approach for the elimination of schistosomiasis:a longitudinal study in a historically hyperendemic region in the lower reaches of the Yangtze River,China from 2005 to 2014

Background:Although great success has been achieved,schistosomiasis remains a major public health concern in China,and the remaining core endemic regions are concentrated along the middle and lower reaches of the Yangtze River.In this longitudinal study,we evaluated the effectiveness of a multidisciplinary,integrated approach for schistosomiasis elimination in a historically hyper-endemic region in the lower reaches of the Yangtze River,China over the 10-year period from 2005 through 2014.Methods:A three-step roadmap for schistosomiasis elimination was designed in the study site,and multidisciplinary,integrated interventions were implemented by the health,agriculture,water resources development,land and resources,and forestry sectors from 2005 to 2014,including chemotherapy for infected individuals,health education,management of the source of Schistosoma japonicum infection,and intermediate host snail control.The annual number of schistosomiasis patients,S.japonicum infection in humans,bovines and Oncomelania hupensis snails,and water infectivity were observed to assess the effectiveness of the multidisciplinary,integrated approach for the elimination of schistosomiasis.Results:There was a tendency towards a gradual decline in both the number of schistosomiasis cases and the prevalence of S.japonicum human infection across the study period from 2005 through 2014.No S.japonicum human infection was detected since 2012,and no acute infection was seen since 2006.During the study period,no infection was found in bovines,and a 0.03%overall infection rate was observed in O.hupensis snails.Since 2009,no infected snails were identified,and the area of both snail habitats and infected snail habitats appeared a reduction over the study period.Following the 3-year multidisciplinary,integrated control,infection control was achieved,and transmission control was achieved after 6-year implementation,with all infected snails and water infectivity eliminated;in addition,the 10-year implementation resulted in interruption of schistosomiasis transmission in the study site in 2014.Conclusions:The results of the present 10-year longitudinal study demonstrate that the multidisciplinary,integrated approach is effective for the elimination of schistosomiasis as a public health problem in the lower reaches of the Yangtze River,China.

An integrated environmental improvement of marshlands:impact on control and elimination of schistosomiasis in marshland regions along the Yangtze River,China

Background:Schistosomiasis is a global snail-transmitted infectious disease of poverty.Transmission control had been achieved in China in 2015 after the control efforts for over 60 years.Currently,the remaining core regions endemic for Schistosoma japonicum are mainly located in the marshland and lake regions along the Yangtze River basin.Methods:During the period from 2001 through 2015,an integrated environmental improvement of the marshlands was carried out through the implementation of industrial,agricultural and resources development projects in Yizheng County along the Yangtze River.S.japonicum infection in humans,livestock and snails was estimated by serology,stool examination,hatching technique and microscopy during the 15-year study period to evaluate the effect of the integrated environmental improvement on control and elimination of schistosomiasis.Results:A 0.05%overall rate of S.japonicum infection was observed in snails during the 15-year study period,and no infected snails were detected since 2012.The overall prevalence of S.japonicum infection was 0.09%in humans during the study period,and no human infection was found since 2012.In addition,only 13 bovines were identified with S.japonicum infection in 2003 during the 15-year study period,and since 2004,no infection was found in livestock.Conclusion:The results of the present study demonstrate that the implementation of industrial,agricultural and water resources development projects,not only alters snail habitats in marshland regions,and promotes local economic development,which appears a win-to-win strategy to block the transmission of S.japonicum and accelerate socio-economic development along the Yangtze River.