A centenary of Robert T. Leiper's lasting legacy on schistosomiasis and a COUNTDOWN on control of neglected tropical diseases.

Part of Robert T. Leiper's (1881-1969) lasting legacy in medical helminthology is grounded on his pioneering work on schistosomiasis (Bilharzia). Having undertaken many expeditions to the tropics, his fascination with parasite life cycles typically allowed him to devise simple preventive measures that curtailed transmission. Building on his formative work with others in Africa and Asia, and again in Egypt in 1915, he elucidated the life cycles of African schistosomes. His mandate, then commissioned by the British War Office, was to prevent and break transmission of this disease in British troops. This he did by raising standing orders based on simple water hygiene measures. Whilst feasible in military camp settings, today their routine implementation is sadly out of reach for millions of Africans living in poverty. Whilst we celebrate the centenary of Leiper's research we draw attention to some of his lesser known colleagues, then focus on schistosomiasis in Uganda discussing why expanded access to treatment with praziquantel is needed now. Looking to WHO 2020 targets for neglected tropical diseases, we introduce COUNTDOWN, an implementation research consortium funded by DFID, UK, which fosters the scale-up of interventions and confirm the current relevance of Leiper's original research.

Schistosomiasis--a rich vein of research.

The expansion in the volume of research activity over the last 100 years and the acceleration of technological change that underpins the nature and, to a lesser extent, the quality of the science we do, means that those in science today have little time, or indeed opportunity, for reflection on some of the pioneering efforts within their fields. From the first discovery of schistosome parasites in Egypt in 1851 by Theodor Bilharz, research on schistosomiasis has provided valuable insights into many wider aspects of biology and medicine and has attracted an array of colourful and dynamic scientists who have made major advances through elegant experimentation.

[Strategy of schistosomiasis elimination and its effects in Jinhu County, Jiangsu Province].

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.

[Endemic status and control of animal schistosomiasis in China].

This paper describes the damages caused by animal schistosomiasis and the role of animals in the transmission of schistosomiasis in China and reviews the progress of animal schistosomiasis control and the endemic status of animal schistosomiasis at various stages. Although the endemic situation of animal schistosomiasis has been effectively controlled, there are still multiple factors that affect the transmission of schistosomiasis, and there are still risks leading to reemergence or rebounding of schistosomiasis in local areas. Strengthening of schistosomiasis surveillance as well as the prevention and control effects in key areas, consolidation of schistosomiasis control achievements, resolving of key technical problems in the elimination of animal schistosomiasis and development of precise technical measures and strategies are needed to accelerate the progress towards the elimination of schistosomiasis in China.

The effectiveness of water treatment processes against schistosome cercariae: A systematic review.

BACKGROUND: Schistosomiasis is one of the most disabling neglected tropical diseases, ranking second in terms of years lived with disability. While treatment with the drug praziquantel can have immediate beneficial effects, reinfection can occur rapidly if people are in contact with cercaria-infested water. Water treatment for schistosomiasis control seeks to eliminate viable cercariae from water, thereby providing safe alternative water supplies for recreational and domestic activities including laundry and bathing. This provision may reduce contact with infested water, which is crucial for reducing reinfection following chemotherapy and cutting schistosome transmission. METHODOLOGY: A qualitative systematic review was carried out to summarize the existing knowledge on the effectiveness of water treatment in removing or inactivating human schistosome cercariae. Four online databases were searched. Studies were screened and categorized into five water treatment processes: storage, heating, chlorination, filtration, and ultraviolet (UV) disinfection. CONCLUSIONS: All five water treatment methods can remove or inactivate cercariae in water, and hence produce cercaria-free water. However, reliable design guidelines for treating water do not exist as there are insufficient data. Overall, the review found that cercariae are inactivated when storing water for 10-72 hours (depending on temperature), or with chlorination values of 3-30 mg-min/l. UV fluences between 3-60 mJ/cm2 may significantly damage or kill cercariae, and sand filters with 0.18-0.35 mm grain size have been shown to remove cercariae. This systematic review identified 67 studies about water treatment and schistosomiasis published in the past 106 years. It highlights the many factors that influence the results of water treatment experiments, which include different water quality conditions and methods for measuring key parameters. Variation in these factors limit comparability, and therefore currently available information is insufficient for providing complete water treatment design recommendations.

Health Education as an Important Component in the National Schistosomiasis Control Programme in The People's Republic of China.

Schistosomiasis control programme in The People's Republic of China had promoted the mass mobilization of health education in various forms, such as films, drama, traditional opera, poems, slogans, posters, exhibits. This paper is trying to review the impacts of those forms on different endemic settings and targeted populations. In the future, health education and health promotion will still be the effective strategy and one of the interventions in the national control programme for schistosomiasis and other infectious diseases, even in the pre- or posttransmission stages. With the social and economic development and improvement of people's living standard, it is necessary to establish a sustainable mechanism, in combination of health education with health guarantee of improving the quality of life, improving the production and living conditions, changing the unhealthy production methods and lifestyle of the residents in the endemic areas, in order to reach the goal of schistosomiasis elimination in The People's Republic of China.

Policy Support and Resources Mobilization for the National Schistosomiasis Control Programme in The People's Republic of China.

Schistosomiasis remains a public health problem in many developing countries around the world. After the founding of The People's Republic of China, from 1949 till date, all levels of government, from central to local, have been attaching great importance to schistosomiasis control in The People's Republic of China. With considerable policy support and resources mobilization, the national schistosomiasis control programmes have been implemented during the past 65years. Here, we summarize the successful experience of schistosomiasis control during the process. Recommendations for the future management of the Chinese national schistosomiasis elimination programme are put forward after considering the remaining challenges, shortcomings and lessons learnt from 65years of schistosomiasis control drives in The People's Republic of China. They will help to sustain past achievements, foster the attainment of the ultimate goal of schistosomiasis elimination for the country and provide reference for schistosomiasis control programme in other countries.

China-Africa and China-Asia Collaboration on Schistosomiasis Control: A SWOT Analysis.

Schistosomiasis, a disease caused by a trematode, parasitic worm, is a worldwide public health problem. In spite of great progress with regard to morbidity control, even elimination of this infection in recent decades, there are still challenges to overcome in sub-Saharan Africa and endemic areas in Southeast Asia. Regarded as one of the most successful countries with respect to schistosomiasis control, The People's Republic of China has accumulated considerable experience and learnt important lessons in various local settings that could benefit schistosomiasis control in other endemic countries. Based on an analysis of conceived strengths, weaknesses, opportunities and threats (SWOT) of potential collaborative activities with regard to schistosomiasis in Africa and Asia, this article addresses the importance of collaborative efforts and explores the priorities that would be expected to facilitate the transfer of Chinese experience to low- and middle-income countries in Africa and Asia.

Schistosomiasis: Traverers in Africa.

Schistosomiasis is a parasitic infection acquired through freshwater exposure in the tropics. It is an infection that can have devastating implications to military personnel if it is not recognized and treated, especially later in life. While there is an abundance of information available about schistosomiasis in endemic populations, the information on nonendemic populations, such as deployers, is insufficient. Definitive studies for this population are lacking, but there are actions that can and should be taken to prevent infection and to treat patients. This literary review presents a case study, reviews basic science, and explores the information available about schistosomiasis in nonendemic populations. Specifically, the authors provide recommendations for the prevention, diagnosis, and postexposure management in military personnel.

[Countermeasures and experiences of schistosomiasis control work under new situation of Shengzhou City].

OBJECTIVE: To summarize the experience of Oncomelania hupensis snail control work and explore more effective snail control strategy under the new situation. METHODS: The data of former snail control work and strategies were collected and analyzed in Shengzhou City from 1995 to 2015. RESULTS: The snail area was effectively compressed in recent years, and it was decreased by 46.61% and 26.50% in 2014 and 2015 respectively compared with that in the last year. CONCLUSIONS: To consolidate the snail control achievements, the government should pay more attention to the schistosomiasis control work and establish a targeted effective long-term strategy.

Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best.

BACKGROUND: Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. METHODOLOGY: We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. PRINCIPAL FINDINGS: Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. CONCLUSIONS/SIGNIFICANCE: Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.

The roles of water, sanitation and hygiene in reducing schistosomiasis: a review.

Schistosomiasis is a disease caused by infection with blood flukes of the genus Schistosoma. Transmission of, and exposure to, the parasite result from faecal or urinary contamination of freshwater containing intermediate host snails, and dermal contact with the same water. The World Health Assembly resolution 65.21 from May 2012 urges member states to eliminate schistosomiasis through preventive chemotherapy (i.e. periodic large-scale administration of the antischistosomal drug praziquantel to school-aged children and other high-risk groups), provision of water, sanitation and hygiene (WASH) and snail control. However, control measures focus almost exclusively on preventive chemotherapy, while only few studies made an attempt to determine the impact of upgraded access to safe water, adequate sanitation and good hygiene on schistosome transmission. We recently completed a systematic review and meta-analysis pertaining to WASH and schistosomiasis and found that people with safe water and adequate sanitation have significantly lower odds of a Schistosoma infection. Importantly though, the transmission of schistosomiasis is deeply entrenched in social-ecological systems, and hence is governed by setting-specific cultural and environmental factors that determine human behaviour and snail populations. Here, we provide a comprehensive review of the literature, which explores the transmission routes of schistosomes, particularly focussing on how these might be disrupted with WASH-related technologies and human behaviour. Additionally, future research directions in this area are highlighted.

[Effect of comprehensive schistosomiasis control in Changzhou City from 2004 to 2014].

OBJECTIVE: To evaluate the effect of comprehensive schistosomiasis control in Changzhou City in recent 10 years, so as to provide the evidences for formulating the future prevention and control strategy. METHODS: The work reports and the data of the schistosomiasis comprehensive control projects in Changzhou City from 2004 to 2014 were collected, the infection status of residents and livestock as well the Oncomelania hupensis snail situation were analyzed, and the implementation effect of the comprehensive control projects was evaluated. RESULTS: From 2004 to 2014, totally 215 368 person-times were examined, and the positive rate of the blood examinations of the population was 0.24% (478/198 356), and there were no positive cases detected out by using the miracidium hatching method. Totally 11 935 domestic animals were detected and no positives were found. From 2004 to 2014, the total area with snails was 92.27 hm2, and marshland, inland and mountain environments accounted for 34.75%, 34.82% and 30.43%, respectively. The newly discovered area with snails was 34.40 hm2, and marshland, inland and mountain environments accounted for 2.62%, 71.22% and 26.16%, respectively. Totally 8 511 snails were dissected and no schistosome infected snails were found. From 2004 to 2014, a total of 242 600 harmless toilets were built, 2 704 700 domestic animals were reared in pens, 5.82 km-long rivers were dredged, 2 250.11 hm2 of protective forests were constructed, a total area of 625.79 hm2 were controlled with molluscicides, and an area of 149.58 hm2 were environmentally transformed. Totally 5.4 million people received health education. The awareness rate of knowledge on schistosomiasis control of residents was 96.00% in 2014. CONCLUSIONS: There exists the risks of snails import and diffusion and schistosomiasis resurrection in Changzhou City, but under the condition of continuous implementation of comprehensive control measures, the endemic situation of schistosomiasis is stable and the control achievement is consolidated in this city.

[Effect of integrated measures on schistosomiasis transmission--interruption in hilly areas].

OBJECTIVE: To evaluate the effect of control integrative measures which persist in snail eradication and chemotherapy on schistosomiasis transmission-interruption in hilly areas. METHODS: The data of integrated control and endemic situation of schistosomiasis from 2004 to 2014 were collected, and the control effect of integrated measures was evaluated. RESULTS: From 2004 to 2014, both the Oncomelania hupensis snail area and density of living snails of Jurong City were reduced from 43.13 hm2 and 1.48 snails/0.1 m2 to 0; the residents' seropositive rate declined continuously; the residents' and students' awareness rates on schistosomiasis control were increased from 88.43% and 82.04% to 92.56% and 95.74% respectively; the snail area was significantly negatively correlated with the coverage rate of snail control (r = -0.864, P < 0.05). CONCLUSIONS: In the hilly areas, the schistosomiasis control integrated measures which persist in snail eradication and chemotherapy could control the endemic situation rapidly and steadily, accelerating to achieve the goal of schistosomiasis transmission-interruption.

[Impact of implementation of Three Gorges Project on schistosomiasis endemic situation and control in Nanjing City].

OBJECTIVE: To understand the changes of hydrological regime in the Yangtze River and schistosomiasis endemic situation in Nanjing City after the implementation of Three Gorges Project. METHODS: The data of hydrological regime of the Yangtze River, schistosomiasis epidemic situation, and Oncomelania hupensis snail status were collected and analyzed in Nanjing City from 2002 to 2012. RESULTS: After the implementation of the Three Gorges Project in 2003, the water level of the Yangtze River slightly rose from January to April, the average water levels in May and August both reduced compared with those in 2002, and the time of water withdrawal was moved up. The water level of the Yangtze River slightly reduced from November to December. The endemic situation of schistosomiasis showed a decline tendency in the areas along the Yangtze River in Nanjing City. In 2012, the rates of human and bovine infected with Schistosoma japonicum both reduced by 100% as compared with those in 2002, and the snail area, infected snail area and snail density were reduced by 48.45%, 100% and 95.76% respectively as compared with those in 2002. CONCLUSION: After the implementation of the Three Gorges Project, the schistosomiasis endemic situation shows a decline tendency in the areas along the Yangtze River in Nanjing City, but the long-term monitoring still need to be carried out.

[Analysis of epidemic situation and control strategy of schistosomiasis in Jiu- jiang City from 2008 to 2014].

OBJECTIVE: To understand the epidemic situation of schistosomiasis in Jiujiang City, so as to provide the evidence for formulating further control strategy. METHODS: The data of schistosomiasis control were collected in Jiujiang City from 2008 to 2014. and the indicators including the annual schistosome infections of human and cattle, acute schistosome infection, outbreak of schistosomiasis endemic, schistosome infected Oncomelania hupensis snails were analyzed statistically. RESULTS: Compared with 2008, in 2014, the infection rates of schistosomiasis declined by 98.40% and 92.54% in human and cattle respectively. The area of schistosome infected snails decreased from 103.24 hm² to zero. The occurrence rate of frames with snails and density of living snails declined from 14.86% and 0.334 5/0.1 m² to 6.89% and 0.126 5/0.1 m², respectively. The acute schistosomiasis infection cases occurred except 2011 and 2014. CONCLUSION: The control strategy emphasizing on infection sources control is effective in Jiujiang City, but the risk of schistosomiasis still exists, and the risk control and schistosomiasis control strategy should be strengthened.

[Effect of standardized construction of laboratories of schistosomiasis control institutions in Hubei Province in 2013].

OBJECTIVE: To investigate the effect and current situation of the standardized construction of laboratories of schis- tosomiasis control institutions in Hubei Province, so as to provide the evidence for establishing and improving the quality control system of diagnosis of schistosomiasis after the transmission of schistosomiasis was under control. METHODS: According to the procedures of self-examination, field operation, and laboratory on-site, five laboratories were assessed, and all the results were analyzed comparatively. RESULTS: The average number of staffs were (7.00±1.58) persons, and the staffs of the laboratories of the schistosomiasis control institutions with senior professional titles in the city level were more than that in the county level (t = 5.563, P < 0.05). The average space was (3.20±1.64) rooms, and the average area was (117.00±88.29) m2. The average score of field operation was (96.40±4.49) points. The average score of laboratory on-site assessment was (106.6±6.15) points. The highest and lowest of the laboratory on-site assessment scores were environment and facilities (19.60 ± 0.55) points and management system of laboratory quality control (15.70±2.39) points (F = 2.869, P < 0.05), respectively. CONCLUSION: The cultivation of laboratory staff should be strengthened, and the diagnostic capacity should be maintained and improved. The laboratory quality control system should be paid more attention to, and the construction and management of schistosomiasis laboratories should be standardized.

[Measures and effectiveness of comprehensive schistosomiasis control along Xinglong River in Qianjiang City].

OBJECTIVE: To evaluate the effect of comprehensive control of schistosomiasis along the Xinglong River in Qianjiang City, so as to provide the evidence for improving schistosomiasis control. METHODS: The comprehensive control measures including infection source control and Oncomelania hupensis snail eradication were surveyed along the Xinglong River in Qianjiang City. RESULTS: The prevalence of schistosomiasis was under control, that was the human and cattle infection rates decreased by 53.77% and 100% respectively, the snail area decreased by 26.9%, the mean density of living snails decreased by 25.5%, and no infected snails was found. CONCLUSIONS: The comprehensive control measures along the Xinglong River are effective, and the management and surveillance of snail environments still should be strengthened.

From katayama to the Dakhla Oasis: the beginning of epidemiology and control of bilharzia.

Treatment of schistosomiasis is now simple and control protects millions in Brazil, China and Egypt and many thousands in other countries. It is difficult, therefore, to visualise the frustration and despair of scientists and clinicians in Africa, and in Egypt in particular, at the beginning of the century faced with a disease described as 'perhaps the most dreadful of the remaining plagues of Egypt' (Madden, P.C., 1910). It was known to be caused by a trematode worm (discovered by Bilharz in 1852), but apparently with a life-cycle atypical of other parasites of that class in that the worms are unisexual and that no intermediate host had been identified. The cause of the disease was known but there was no treatment, and the question 'How are people infected?' remained unanswered. Rational preventive and control measures would be possible only when this question was answered. Investigations to answer it, and early attempts at control, constitute the basis of the following historical review. The controversies, theories and fertile imaginations of the eminent scientists, that preceded the unravelling of the schistosome life-cycle, are discussed and observations, techniques and ideas of the early researchers that were forgotten only to be rediscovered many years later, are highlighted.

Treatment and re-treatment strategies for schistosomiasis control in different epidemiological settings: a review of 10 years' experiences.

This paper reviews 10 years' experience with schistosomiasis control in different endemic settings in Africa, Asia and the Americas. Research projects, pilot programs and long-term large-scale programs with the objective of controlling morbidity have been included in the review. Major advances in diagnostic tools and rapid assessment techniques have evolved during the decade making it possible to follow changes in pathology after treatment and to get baseline epidemiological information at very low cost. At the same time prices of drugs like praziquantel has declined dramatically (to