Search

Over the several decades, China has been incessantly optimizing control strategies in response to the varying epidemic situations of schistosomiasis. We evaluated continuously the changing prevalence under different control strategies of two villages, Sanlian and Guifan, in China through five phases lasting 37 years. We tested residents, calculated prevalence and discussed change causes. We found the prevalence in Sanlian did not differ significant from that of Guifan ( p = 0.18) in 1981, but decreased to 2.66%, much lower than Guifan's 11.25%, in 1984 ( p = 0). Besides, prevalence in Guifan increased to 21.25% in 1987, while in Sanlian it rose to 20.78% until 1989. Those data confirmed that praziquantel combined with snail control could better reduce the prevalence. From 1992 to 1994, the prevalence in the two villages displayed downtrends, which showed the World Bank Loan Project worked. From 1995 to 2004, repeated oscillations with no obvious change trend was seen. Since 2005, the prevalence in both villages has shown a significant downtrend ( p < 0.05), which suggests the integrated strategy is effective. We considered the control strategies were implemented suitably in the study area under changing social circumstances. Adjusting the strategy in consideration of social transformations is necessary and vital. The experience may be useful for policy making of other epidemic areas with an analogous situation.

Background: Schistosomiasis was severely prevalent in Yunnan Province, and it is difficult to achieve its elimination by convention approaches due to complexity of the nature. We explored the comprehensive model to eliminate schistosomiasis in Eryuan County, Yunnan Province, the People's Republic of China, through integration with the ecological protection programme in Erhai Lake, in order to promote an efficient elimination strategy. We expected that this model is able to be tailored to other local settings, which help achieve the goal of precisely eliminating the disease in Yunnan Province., Methods: Eryuan County of Yunnan Province was chosen as the study area, where the data on environmental protection activities in Erhai Lake and on the schistosomiasis control programme were collected through different departments of Erhai County government since 2015. System modelling was performed using system dynamics software to establish a simulation model in order to evaluate the effectiveness of intervention activities., Results: Ecological approaches to control schistosomiasis in Eryuan County consist of three major components: (i) implementing precise interventions to stop schistosomiasis transmission by means of controlling the source of infection, blocking the biological transmission chains and cutting off the route of disease transmission; (ii) employing ecological approaches to improve the co-effectiveness of environmental protection and schistosomiasis prevention in the study area; and (iii) strengthening the professional skills of personnel involving in the schistosomiasis control programme. Simulation results showed that this strategy could speed up the progress of schistosomiasis control programme moving from the control stage to the elimination stage., Conclusions: Ecological approaches implemented in schistosomiasis endemic areas of the Eryuan region are able to improve the co-effectiveness of environmental protection and schistosomiasis control, providing a new avenue for eliminating schistosomiasis thanks to the application of precise interventions.

Since 2004, the national schistosomiasis control strategy in China has shifted from the morbidity control strategy (conventional strategy) to an integrated strategy (new strategy). We investigated the effectiveness of the new strategy and compared it against the conventional strategy. We retrieved from electronic databases the literature regarding the new strategy published from 2000 to 2017. The effect of the new or conventional strategy on infection by Schistosoma japonicum of humans and snails (Oncomelania hupensis) was evaluated with pooled log relative risk (logRR). A total of only eight eligible publications were included in the final meta-analysis. The results showed that implementation of the new strategy reduced the infection risk by 3-4 times relative to the conventional strategy. More specifically, the conventional strategy caused a reduction in both human (logRR = 0.56, 95% CI: 0.12-0.99) and snail infections (logRR = 0.34, 95% CI: -0.69-1.37), while the new strategy also significantly reduced both human (logRR = 1.89, 95% CI: 1.33-2.46) and snail infections (logRR = 1.61, 95% CI: 1.06-2.15). In contrast to the conventional strategy, the new strategy appeared more effective to control both human (logRR difference = 1.32, 95% CI: 0.78-1.86) and snail infections (logRR difference = 1.53, 95% CI: 0.76-2.31). Our data demonstrate that the new integrated strategy is highly effective to control the transmission of S. japonicum in China, and this strategy is recommended for schistosomiasis elimination in other affected regions across the world, with adaptation to local conditions., (© C. Qian et al., published by EDP Sciences, 2018.)

The prevalence of human schistosomiasis and soil-transmitted helminthiasis (STH) has decreased significantly in the People's Republic of China (P.R. China), particularly after 2005 when the national control programmes were reinforced by forming of integrated control strategies. Furthermore, social-economic development also contributed to the decrease of schistosome and soil-transmitted helminth infections. The prevalence of the zoonotic helminthiasis, including clonorchiasis and echinococcosis, on the other hand, is either underestimated or has in fact increased due to changes in social and environmental factors. In comparison with the control strategies in force and their effects on those four kinds of helminthiasis, the challenges and control priorities for the potential transfer from control to elimination of each disease is reviewed, to provide evidence for policy-makers to act upon., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Schistosomiasis japonica has a long history in the Philippines. In 1975, 24 endemic provinces were identified in the northern, central, and southern islands of the Philippines. More than five million people were at risk, with approximately one million infected. In 2003, new foci of infection were found in two provinces in the north and central areas. For the past 30 years, human mass drug administration (MDA), utilizing the drug praziquantel, has been the mainstay of control in the country. Recent studies have shown that the schistosomiasis prevalence ranges from 1% to 50% within different endemic zones. Severe end-organ morbidity is still present in many endemic areas, particularly in remote villages with poor treatment coverage. Moreover, subtle morbidities such as growth retardation, malnutrition, anemia, and poor cognitive function in infected children persist. There is now strong evidence that large mammals (e.g. water buffaloes, cattle) contribute significantly to disease transmission, complicating control efforts. Given the zoonotic nature of schistosomiasis in the Philippines, it is evident that the incidence, prevalence, and morbidity of the disease will not be controlled by MDA alone. There is a need for innovative cost-effective strategies to control schistosomiasis in the long term., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Schistosomiasis japonica remains a significant public-health problem in China. This study evaluated cost-effectiveness of a comprehensive schistosomiasis control program (2003-2006). The comprehensive control program was implemented in Zhangjia and Jianwu (cases); while standard interventions continued in Koutou and Xiajia (controls). Incurred costs were documented and the schistosomiasis comprehensive impact index (SCI) and cost-effectiveness ratio (Comprehensive Control Program Cost/SCI) were applied. In 2003, prevalence of Schistosoma japonicum infection was 11.3% (Zhangjia), 6.7% (Jianwu), 6.5% (Koutou), and 8.0% (Xiajia). In 2006, the comprehensive control program in Zhangjia and Jianwu reduced infection to 1.6% and 0.6%, respectively; while Koutou and Xiajia had a schistosomiasis prevalence of 3.2% and 13.0%, respectively. The year-by-year SCIs in Zhangjia were 0.28, 105.25, and 47.58, with an overall increase in cost-effectiveness ratio of 374.9%-544.8%. The SCIs in Jianwu were 16.21, 52.95, and 149.58, with increase in cost-effectiveness of 226.7%-1,149.4%. Investment in Koutou and Xiajia remained static (US$10,000 unit cost). The comprehensive control program implemented in the two case villages reduced median prevalence of schistosomiasis 8.5-fold. Further, the cost effectiveness ratio demonstrated that the comprehensive control program was 170% (Zhangjia) and 922.7% (Jianwu) more cost-effective. This work clearly shows the improvements in both cost and disease prevention effectiveness that a comprehensive control program-approach has on schistosomiasis infection prevalence.

Backgrounds: Human schistosomiasis is caused by schistosome, with annual loss of over 70 million disability adjusted life years in the world. China is endemic with Schistosoma japonicum and large-scale chemotherapy with praziquantel has become the mainstay of control in China since 1990s. However, the control effects of mass treatment in the field have been uneven. Moreover, mass treatment has come into a wide use in other countries with limited health resources. Therefore, a better understanding of the control effect of mass treatment is in an urgent need., Methods: We performed a systematic search of the literature to investigate the control efficiency of annual community-wide treatment (ACWT, treatment to an entire community without any preliminary screening) with a single dose of PZQ (40 mg kg(-1) bodyweight) against schistosome in humans in China. Three Chinese literature databases, including China National Knowledge Infrastructure, WanFang and Chinese Scientific Journal Databases, and the PubMed were searched. Pooled prevalence ratios (prevalence after to before treatment) were used to assess effect. Our protocol is available on PROSPERO (No. CRD42013003628)., Results: 22 articles were included. Meta-analyses on data from 18 studies on one round of ACWT, 17 studies on two consecutive rounds and 6 studies on three consecutive rounds were performed. The results showed control effects of ACWT plus other measures were statistically significant, with prevalence ratios being 0.38 (0.31, 0.46) for one round, 0.28 (0.22, 0.35) for two rounds and 0.22 (0.10, 0.46) for three rounds. When ACWT was performed alone or with health education only, the values for one and two rounds were 0.389 (0.307, 0.492) and 0.348 (0.300, 0.403), respectively., Conclusions: The control effect of ACWT alone or with other measures is significant and increases with the number of rounds. Such program is recommended in high endemic areas and the criteria yet merit further assessment.

In 2009, Wang et al.'s field trial published in the New England Journal of Medicine, reported that a comprehensive strategy aiming to reduce the roles of humans and cattle as sources of Schistosoma japonicum infection in snails was implemented and proved effective and promising in dramatically reducing the percentage of infected humans and snails, which had been extended to other endemic provinces in China afterwards. This implies that the integrated schistosomiasis-control strategies of interventions including political will, financial support and residents' participation to control human and bovine sources of S. japonicum infection in snails may direct to successfully interrupt the parasitic transmission and to ultimately eliminate schistosomiasis. Confusingly, however, the role of health education, which is a critical part of the integrated strategy and should play an active role in schistosomiasis control, was not reflected. We wish the authors to provide the readers a better and clearer statement of the role of health education as part of the integrated control strategy and so we write this comment.

Objective: To evaluate the effect of Ecological Civilized Homestead Construction on schistosomiasis control., Methods: The data of ecological civilized homestead construction and schistosomiasis control were collected and analyzed in Meiwan Village, Shuangqiao Town, Danling County, Sichuan Province from 2004 to 2010., Results: Ecological Civilized Homestead Construction was carried out from 2004 to 2010. Totally 454 bio-gas pools were built. All the farmers used well water. The popularized rates of the household bio-gas pool, sanitary toilet, sewage treatment pool reached 100%. The number of cattle was 4, which decreased by 91.30% compared with that in 2004, and all the cattle were fed in captivity. The schistosome infection rates of populations were 0.26% and 0.30% in 2005 and 2008, respectively, and nobody was infected in other years. The infection rate of cattle was 0 from 2004 to 2010. The awareness rate of knowledge about schistosomiasis control achieved 100% in the population over 6 years old. Most of the farmers could use certain protective measures while they were farming., Conclusion: The effect of ecological civilized homestead construction on schistosomiasis control is remarkable.

Background: Schistosomiasis japonica remains a major public health concern in China. There are many interventions implemented to control the transmission of the disease. The purpose of the present study was to investigate the effects of an integrated control strategy for schistosomiasis control., Methods: An integrated control strategy for schistosomiasis japonica with emphasis on removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water and building lavatories and latrines and providing boats with fecal-matter containers was implemented in 107 villages of the lower reaches of the Yangtze River, Jiangsu Province, China, during a 32-month period from May 2005 to 2008, and the effectiveness was investigated., Results: Following the effects of the comprehensive control, the snail habitat, infected snail habitat, snail infection rate, and S. japonicum prevalence in both humans and livestock all appeared a declining trend year by year, with reductions of 47.88%, 94.29%, 92.55%, 96.94%, and 100% compared with those before the comprehensive control. In addition, all of the 17 counties achieved the infection control in 2007, and 7 reached the criteria of transmission control in 2008. The confirmed snail habitats reduced from 107 to 20, and the acute infections have also been controlled for 2 successive years since 2007., Conclusions: The integrated control strategy for schistosomiasis japonica is effective to control the transmission of S. japonicum.

Objective: To evaluate the effect of comprehensive control for schistosomiasis in key areas of Jiangsu Province., Methods: The basic data and the data of implementation of comprehensive control measures were collected from the key areas of Jiangsu Province, including 30 townships, 87 marshlands and 78 anchor points. A field survey was carried out to investigate the Oncomelania snail status by using the systematic sampling method and schistosomiasis morbidity in humans and animals in the 12 key counties (districts). The changes of snail status and morbidity of humans and animals were statistically analyzed in key counties (districts) where comprehensive control measures was implemented, and the effects of schistosomiasis control before and after the implementation of the comprehensive control were compared., Results: From 2008 to 2010, a total of 84 100 harmless latrines were constructed, 339 600 persons were examined, 2.6938 million people received health education, 112 000 protective creams and 798 000 publicity materials were allocated, 9 085 domestic animals were reared in pens, 11 800 domestic animals were examined, 130 high-risk cattle were eliminated in 30 key townships of 12 countries (districts), Jiangsu Province. A total of 19 640.78 hm2 were controlled with molluscicides, 798 warning tablets were placed, 116.07 hm2 of farmlands were ploughed up and planted, 306.80 hm2 were dug for fish culture, and 506.74 hm2 were planted with trees for snail control in 87 high-risk marshlands. A total of 118.83 million Yuan were invested into the water resources development projects, 39.82 km-long rivers were dredged, 70.04 km-long bank were concreted, 30 culvert gates were re-constructed, and 22 snail sedimentation tanks were built. In the 78 anchor points, 95 harmless public toilets were built, 3 192 stool container were allocated, 28 700 boatmen were examined, 71 600 protective creams and 53 200 publicity materials were allocated, and 46 600 persons received health education. Following the implementation of comprehensive control, the settings with infected snails, infected snail areas, infection rates of snails reduced from 75, 802.73 hm2 and 0.10% before the comprehensive control in 2007 to all 0 in 2010, with reduction rates of all 100%. The infection rates of schistosome in both humans and domestic animals appeared declining trends in 12 counties (districts) from 2005 to 2010, and the human infection rates were 0.16%, 0.04%, 0.02%, 0.02%, 0.01% and 0.01%, respectively, while being 0.11%, 0.05%, 0, 0, 0 and 0, respectively in domestic animals. During the period of comprehensive control, totally 45 transmission-controlled townships and 183 villages were newly added. In 2010, all of the 12 counties (districts) reached the criteria of schistosomiasis transmission control., Conclusions: The comprehensive control with emphasis on the key areas where infected snails are found, is an effective measure to further facilitate schistosomiasis control and rapidly control the transmission of schistosomiasis.

This paper discusses the issues and suggestions in the implementation of the new schistosomiasis control strategy with emphasis on controlling sources of infection in lake and marshland endemic regions in order to accelerate the implementation of the new control strategy.

Triggered by a fascinating publication in the New England Journal of Medicine detailing China's new multi-pronged strategy to control and eventually interrupt the transmission of Schistosoma japonicum, this PLoS Neglected Tropical Diseases Debate critically examines the generalizability and financial costs of the studies presented from the marshlands of the lake region. Edmund Seto from the University of California and colleagues emphasize that the epidemiology and control of schistosomiasis varies according to the social-ecological context. They conjecture that the successful intervention packages piloted in the lake region is not fully fit for the hilly and mountainous environments in Sichuan and Yunnan provinces, and hence call for more flexible, setting-specific, and less expensive control strategies. In response, Xiao-Nong Zhou from the National Institute of Parasitic Diseases at the Chinese Center of Disease Control and Prevention and colleagues explain the steps from designing pilot studies to the articulation and implementation of a new national control strategy through a careful process of scaling-up and adaptations. Finally, the two opponents converge. The need for integrated, intersectoral, and setting-specific control measures is stressed, supported by rigorous surveillance and continuous research. Experiences and lessons from China are important for shaping the schistosomiasis elimination agenda.

The effectiveness of a comprehensive schistosomiasis japonica control program implemented in 8 villages along the Yangtze river in Jiangsu province from 2005 to 2008 was studied. Control measures included snail control, chemotherapy of humans and livestock, health education, and transmission cycle interruption using sanitation in dwellings and at anchorage sites for fishermen and sailors. The Schistosoma japonicum prevalence among residents and livestock, the total area of snail habitats, the Oncomelania hupensis snail density, and the percentage of infected snails served as indicators for the effectiveness of the control efforts. After 4 years of program implementation, the seroprevalence in humans had decreased from 9.03% to 3.24% (P < 0.001) and the parasitological prevalence among males had decreased from 0.42% to 0.12% (P = 0.004). Among females, it remained stable at a low level. The S. japonicum prevalence in livestock had decreased from 2.94% to 0% (P < 0.001). Additionally, the area where infected snails could be found had shrunk from 89.99 hectares (ha) to 16.00 ha, the snail density had decreased from 0.56 to 0.32 per 0.1m(2), and the percentage of infected snails had dropped from 0.38% to 0.12% (all P < 0.001). The results demonstrate that an integrated schistosomiasis japonica control strategy focusing on the main transmission cycles and reservoirs and combines chemotherapy, infrastructure interventions and health education combined with robust surveillance is feasible and allows to effectively control S. japonicum., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Objective: To establish an approach to monitor the Schistosoma japonicum miracidia in waterbody of the Yangtze River, and monitor the infectivity of water body, so as to provide the evidence for tracing and controlling infection source and interrupting the transmission of schistosomiasis, and Oncomelania snail control., Methods: The floating bottle-nylon bag sentinel snails method was employed. A total of 45 surveillance sites were selected along the Jiangsu section of the Yangtze River, 500 snails were placed into each site from May to September, once every month. Twenty-eight hours later, all the snails were transferred and raised in an incubator at 25 degrees C. Two months after the first recovery, the snail infection was detected each month by using the cercaria-shedding test. Three months after the final placement, all the snails were dissected for observation of the infection. The activities of humans and domestic animals were surveyed in the settings where infected snails were found. The database of surveillance results of sentinel snails in the Yangtze River, Jiangsu Province was established, and the geographical distribution map of site with infected snails was drawn, and the probability that snails were infected with S. japonicum was estimated., Results: A total of 44 717 sentinel snails were placed in 45 sites during the period of 5 months, and 43 477 recovered, with a recovery rate of 97.23%. A total of 81 410 snails were detected by the cercaria-shedding test, no infections were found. A total of 13 033 snails were dissected, and 5 were infected, with an infection rate of 0.038%. The probability of snail infection in water was 4.11 out of a million. Five sites with infected snails were found in 45 sites, with an occurrence rate of 11.11%. The sites with infected sentinel snails were distributed in south bank (3, 21.43%), north bank (1, 5.56%) and river center (1, 7.69%), respectively. The occurrence rate of sites with infected snails in south bank was 3.8 times more than that in north bank. Among the 5 sites, 3 were anchor points of boat fishermen., Conclusions: The contamination of S. japonicum eggs in south bank of the Yangtze River is higher than that in north bank in Jiangsu Province, and the anchor point of boat fisherman is one of the important contamination regions. The floating bottle-nylon bag sentinel snails testing method is an effective approach to monitor the contamination of S. japonicum eggs in water.

Schistosomiasis japonica, a chronic and debilitating disease caused by the blood fluke Schistosoma japonicum, is still of considerable economic and public health concern in the People's Republic of China, the Philippines, and Indonesia. Despite major progress made over the past several decades with the control of schistosomiasis japonica in the aforementioned countries, the disease is emerging in some areas. We review the epidemiological status and transmission patterns of schistosomiasis japonica, placing it into a historical context, and discuss experiences and lessons with national control efforts. Our analyses reveal that an integrated control approach, implemented through intersectoral collaboration, is essential to bring down the prevalence and intensity of Schistosoma japonicum infections and disease-related morbidity, and to sustain these parameters at low levels. The need for innovation and a sufficiently flexible control approach to adapt interventions in response to the changing nature and challenges of schistosomiasis control from the initial phase of morbidity control to the final state of elimination is emphasised. The aim of the presentation and the analyses is to inspire researchers and disease control managers elsewhere in Asia, Africa, and the Americas to harness the experiences gained and the lessons presented here to improve the control and eventual elimination of schistosomiasis and parasitic diseases.

Background: Schistosoma japonicum causes an infection involving humans, livestock, and snails and is a significant cause of morbidity in China., Methods: We evaluated a comprehensive control strategy in two intervention villages and two control villages along Poyang Lake in the southeastern province of Jiangxi, where annual synchronous chemotherapy is routinely used. New interventions, implemented from 2005 through 2007, included removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water and building lavatories and latrines, providing boats with fecal-matter containers, and implementing an intensive health-education program. During the intervention period, we observed changes in S. japonicum infection in humans, measured the rate of infection in snails, and tested the infectivity of lake water in mice., Results: After three transmission seasons, the rate of infection in humans decreased to less than 1.0% in the intervention villages, from 11.3% to 0.7% in one village and from 4.0% to 0.9% in the other (P<0.001 for both comparisons). The rate of infection in humans in control villages fluctuated but remained at baseline levels. In intervention villages, the percentage of sampling sites with infected snails decreased from 2.2% to 0.1% in one grassland area and from 0.3% to no infection in the other (P<0.001 for both comparisons). The rate of infection in mice after exposure to lake water decreased from 79% to no infection (P<0.001)., Conclusions: A comprehensive control strategy based on interventions to reduce the rate of transmission of S. japonicum infection from cattle and humans to snails was highly effective. These interventions have been adopted as the national strategy to control schistosomiasis in China., (2009 Massachusetts Medical Society)