Field validation of different intervention modes for the potential transmission risk of schistosomiasis during post-transmission interruption phase.

OBJECTIVE: Precision interventions have been proposed in transmission-interrupted areas to further reduce the potential transmission risk of schistosomiasis. This study aimed to evaluate the effects of different interventions modes for potential transmission risk control. METHODS: Three groups of schistosomiasis-endemic villages were selected in Jiangling county, Hubei province. After baseline surveys in 2020, three intervention models were employed in 2021 and 2022. In Model 1, Oncomelania hupensis snail control in key settings and an integrated strategy with an emphasis on the infectious sources managing was employed. In Model 2, an integrated health education-led strategy with an emphasis on infectious source management was employed. In Model 3, only the integrated strategy with an emphasis on infectious source management was employed. The effects of the different intervention models were examined with multiple indicators after 2 years of intervention using the entropy-weighted technique for order of preference by similarity to ideal solution (TOPSIS), rank-sum ratio (RSR) and fuzzy combination model of entropy-weighted TOPSIS and RSR. RESULTS: Entropy-weighted TOPSIS modeling showed that the Ci values of Model 2 were 0.4434, 0.2759, and 0.3069 in the three pilot villages, Ci values were larger, with top comprehensive ranking. The results of the RSR method showed that the RSR values of Model 2 were 0.75, 0.708, and 0.736 in the three pilot villages, with top comprehensive ranking. The results from the fuzzy combination model of entropy-weighted TOPSIS and RSR showed that implementation of Model 2 resulted in the highest comprehensive ranking among the three models in the three pilot villages under Ci: RSR = 0.1: 0.9, Ci: RSR = 0.5: 0.5 and Ci: RSR = 0.9: 0.1. CONCLUSION: The integrated health education-led strategy with an emphasis on infectious source management was the optimal model to manage the risk of transmission of schistosomiasis during the post-transmission interruption phase.

[Historical review of schistosomiasis prevention and treatment in southern Anhui from 1950 to 1970].

From 1950 to 1970, under the leadership of the central government, workstations for the prevention and control of schistosomiasis were established in the southern Anhui region. In terms of controlling the source of the disease, light and severe epidemic areas were scientifically divided. By opening new ditches to replace old ones, changing paddy fields to dry fields, and using traditional Chinese medicine and Western medicine to prevent the intermediate host of schistosomiasis, oncomelania from surviving. By managing the feces from human and animals and controlling the water source, the transmission route of schistosome eggs has been effectively cut off. At the same time, the education of hygiene awareness among susceptible populations were strengthened. In terms of diagnosis, modern physical and biochemical detection were used to improve the accuracy of diagnosis. In terms of treatment, by combining traditional Chinese medicine and Western medicine, together with the splenectomy, the cure rates were improved. In the process of preventing and controlling schistosomiasis, the governments of Anhui Province and the southern region of Anhui Province achieved good results, providing useful reference for the prevention and control of other diseases.

Molluscicidal activity of plant alkaloids.

Some snail species pose a serious threat for human health, economy, and the environment due to their widespread distribution and the transmission of dangerous parasites causing, among others, schistosomiasis and fascioliasis. Scientists from around the world have been studying the effects of plant extracts on snails for many years in order to find an alternative to molluscicides of synthetic origin. The main purpose of this study was to collect the results obtained so far on the effect of plant alkaloids on snails in the context of their molluscicidal properties. This work presents the results of publications on the effect of plant alkaloids on snails, which were published in the years 1974-2021. The Solanaceae, Papaveraceae, and Asteraceae are the plant families most frequently cited for containing alkaloids with molluscicidal activity. The alkaloids identified as molluscicidal belonged to various groups, of which the most numerous were pseudoalkaloids and tyrosine-derived alkaloids. Most of the tested alkaloids were characterized by a high mortality rate among the studied groups of snails. Based on the collected research results, it was found that plant alkaloids can be extremely useful in the fight against problematic species of snails and cause much lower harm to the environment than synthetic molluscicides.

Critical medical ecology and intersectionality perspectives in schistosomiasis prevention and control in selected communities in Mindanao, the Philippines.

Schistosomiasis japonica remains a public health concern in many areas of the Philippines. Periodic Mass Drug Administration (MDA) to at-risk populations is the main strategy for morbidity control of schistosomiasis. Attaining MDA coverage targets is important for the reduction of morbidity and prevention of complications due to the disease, and towards achieving Universal Health Care. The study employed a qualitative case study design. Key informant interviews and focus group discussions were conducted to provide in-depth and situated descriptions of the contexts surrounding the implementation of MDA in two selected villages in known schistosomiasis-endemic provinces in Mindanao in the Philippines. Data analysis was done using the Critical Ecology for Medical Anthropology (CEMA) model coupled with the intersectionality approach. It was found that within various areas in the CEMA model, enabling as well as constraining factors have been encountered in MDA in the study settings. The interplay of income class, geographical location, gender norms and faith-based beliefs may have led to key populations being missed during the conduct of MDA in the study sites. The constraints faced by the target beneficiaries of MDA, as well as programme implementers, must be addressed to enhance service delivery and to control morbidity due to schistosomiasis. Improving compliance with MDA also requires a holistic, integrated approach to addressing barriers to participation, which are shaped by wider socio-political and power structures.

A novel theatre-based behaviour change approach for influencing community uptake of schistosomiasis control measures.

BACKGROUND: Appropriate behaviour change with regard to safe water contact practices will facilitate the elimination of schistosomiasis as a public health concern. Various approaches to effecting this change have been trialled in the field but with limited sustainable outcomes. Our case study assessed the effectiveness of a novel theatre-based behaviour change technique (BCT), in combination with cohort awareness raising and capacity training intervention workshops. METHODOLOGY: Our study was carried out in four rural communities in the Mwanza region of Tanzania and in the semi-urban town of Kemise, Ethiopia. We adapted the Risk, Attitude, Norms, Ability and Self-regulation (RANAS) framework and four phases using a mixed methods approach. Participatory project phase engagement and qualitative formative data were used to guide the design of an acceptable, holistic intervention. Initial baseline (BL) data were collected using quantitative questionnaire surveys with 804 participants in Tanzania and 617 in Ethiopia, followed by the theatre-based BCT and capacity training intervention workshops. A post-intervention (PI) survey was carried out after 6 months, with a participant return rate of 65% in Tanzania and 60% in Ethiopia. RESULTS: The intervention achieved a significant improvement in the knowledge of schistosomiasis transmission being associated with poorly managed sanitation and risky water contact. Participants in Tanzania increased their uptake of preventive chemotherapy (males: BL, 56%; PI, 73%, females: BL, 43%; PI, 50%). There was a significant increase in the selection of sanitation (Tanzania: BL, 13%; PI, 21%, Ethiopia: BL, 63%; PI, 90%), safe water and avoiding/minimising contact with infested waters as prevention methods in Tanzania and Ethiopia. Some of the participants in Tanzania followed on from the study by building their own latrines. CONCLUSIONS: This study showed that substantial positive behaviour changes in schistosomiasis control can be achieved using theatre-based BCT intervention and disease awareness training. With the appropriate sensitisation, education and stakeholder engagement approaches, community members were more open to minimising risk-associated contact with contaminated water sources and were mobilised to implement preventive measures.

Plant-derived compounds for the treatment of schistosomiasis: Improving efficacy via nano-drug delivery.

Schistosomiasis is a neglected infectious tropical disease that is second in occurrence only to hookworm infection in sub-Saharan Africa. Presently, chemotherapy is the main method of control and treatment of this disease due to the absence of a vaccine. However, Praziquantel, which is the only chemotherapeutic option, lacks efficacy against the early developmental stages of schistosomes. A number of plant-derived compounds, including alkaloids, terpenes and phenolics, have displayed in vitro and in vivo efficacy against Schistosoma species. This review explores how the application of nanotechnology can improve the efficacy of these plant-derived schistosomicidal compounds through the use of nano-enabled drug delivery systems to improve bioavailability.

Statistical Regression Model of Water, Sanitation, and Hygiene; Treatment Coverage; and Environmental Influences on School-Level Soil-Transmitted Helminths and Schistosome Prevalence in Kenya: Secondary Analysis of the National Deworming Program Data.

According to the Kenya National School-Based Deworming program launched in 2012 and implemented for the first 5 years (2012-2017), the prevalence of soil-transmitted helminths (STH) and schistosomiasis substantially reduced over the mentioned period among the surveyed schools. However, this reduction is heterogeneous. In this study, we aimed to determine the factors associated with the 5-year school-level infection prevalence and relative reduction (RR) in prevalence in Kenya following the implementation of the program. Multiple variables related to treatment, water, sanitation, and hygiene (WASH) and environmental factors were assembled and included in mixed-effects linear regression models to identify key determinants of the school location STH and schistosomiasis prevalence and RR. Reduced prevalence of Ascaris lumbricoides was associated with low (< 1%) baseline prevalence, seven rounds of treatment, high (50-75%) self-reported coverage of household handwashing facility equipped with water and soap, high (20-25°C) land surface temperature, and community population density of 5-10 people per 100 m2. Reduced hookworm prevalence was associated with low (< 1%) baseline prevalence and the presence of a school feeding program. Reduced Trichuris trichiura prevalence was associated with low (< 1%) baseline prevalence. Reduced Schistosoma mansoni prevalence was associated with low (< 1%) baseline prevalence, three treatment rounds, and high (> 75%) reported coverage of a household improved water source. Reduced Schistosoma haematobium was associated with high aridity index. Analysis indicated that a combination of factors, including the number of treatment rounds, multiple related program interventions, community- and school-level WASH, and several environmental factors had a major influence on the school-level infection transmission and reduction.

[Strategy for the South-South cooperation on schistosomiasis control under the Belt and Road Initiative].

Following the concerted efforts for nearly 70 years, great successes have been achieved in the national schistosomiasis control programme in China. Currently, the national schistosomiasis control programme in China is facing the challenges to solve the problems during the"final mile"stage towards schistosomiasis elimination, and contribute Chinese experiences, Chinese strategy and Chinese wisdom to the global schistosomiasis control programmes, so as to facilitate the transformation of the joint efforts in the Belt and Road Initiative to a high-quality development, thereby well supporting the activities on global health security. This paper analyzes the current global status of schistosomiasis and the challenges of the global schistosomiasis control programmes, describes the basis for the cooperation on schistosomiasis control among the countries along the Belt and Road Initiative, illustrates the challenges for translation of Chinese experiences and techniques in schistosomiasis control to other diseaseendemic countries, and proposes the patterns and prospects of the South-South cooperation on schistosomiasis control under the Belt and Road Initiative.

Molluscicidal activity and physiological toxicity of quaternary benzo[c]phenanthridine alkaloids (QBAs) from Macleaya cordata fruits on Oncomelania hupensis.

Schistosomiasis is a serious worldwide parasitic disease. One of the best ways to control schistosomiasis is to control the population of Oncomelania hupensis snails. We sought to identify a high-efficiency biogenic molluscicide against Oncomelania with low toxicity, to avoid chemical molluscicide contamination and toxicity in aquatic organisms. We extracted quaternary benzo[c]phenanthridine alkaloids (QBAs) from Macleaya cordata fruits. Molluscicidal activity of the QBAs against Oncomelania was determined using bioassay. Our results showed that the extracted QBAs had a strong molluscicidal effect. In treatment of O. hupensis with QBAs for 48 h and 72 h, the lethal concentration (LC50) was 2.89 mg/L and 1.29 mg/L, respectively. The molluscicidal activity of QBAs was close to that of niclosamide (ethanolamine salt), indicating that QBAs have potential development value as novel biogenic molluscicides. We also analyzed physiological toxicity mechanisms by examining the activity of several important detoxification enzymes. We measured the effect of the extracted QBAs on the activities of glutathione S-transferase (GST), carboxylesterase (CarE), acid phosphatase (ACP), and alkaline phosphatase (AKP) in the liver of O. hupensis. We found that the effects of QBAs on detoxification metabolism in O. hupensis were time and concentration dependent. The activities of GST, CarE, AKP, and ACP in the liver of snails increased significantly in the early stage of treatment (24 h), but decreased sharply in later stages (120 h), compared with these activities in controls. GST, CarE, AKP, and ACP activity in the liver of snails treated with LC50 QBAs for 120 h decreased by 62.3%, 78.1%, 59.2%, and 68.6%, respectively. Our results indicate that these enzymes were seriously inhibited by the extracted QBAs and the detoxification and metabolic functions of the liver gradually weakened, leading to poisoning, which could be the main cause of death in O. hupensis snails.

Community perceptions of mass drug administration for soil-transmitted helminthiasis and schistosomiasis in selected schools in the Philippines.

BACKGROUND: Soil-transmitted helminthiasis (STH) and schistosomiasis are parasitic infections prevalent in tropical and subtropical countries, such as the Philippines. The prevalence of these infections remain high in certain Philippine provinces, despite established mass drug administration (MDA) programs in endemic communities. This study aimed to understand community knowledge and perceptions of these infections to determine their implications on the current control and elimination strategies, including possible barriers to MDA compliance. METHODS: The study was conducted in Northern Samar and Sorsogon, two provinces with the highest STH and schistosomiasis prevalence in the country. Focus group discussions with separate parent and children groups were utilized to gather knowledge and perceptions on STH and schistosomiasis causes, symptoms, treatment, and prevention; and on the deworming drugs and overall program implementation. Data collection in Northern Samar were done in August 2017, while the sessions in Sorsogon took place in May 2018. A cultural construction of disease framework will show how several factors affect MDA participation. RESULTS: Results showed that participants held mostly correct biomedical notions of the infections and expressed willingness to participate in MDA program. However, reservations remained due to a reported lack of information dissemination, lack of confidence in the drugs used, and widespread fear of adverse side effects. CONCLUSION: Addressing these concerns - improving the conduct of the deworming program, incorporating suggestions from the community, and managing potential adverse events - may help raise MDA participation and encourage better personal preventive practices, reducing STH and schistosomiasis prevalence. TRIAL REGISTRATION: N/A.

Assessment of the molluscicidal impact of extracted chlorophyllin on some biochemical parameters in the nervous tissue and histological changes in Biomphalaria alexandrina and Lymnaea natalensis snails.

Biomphalaria alexandrina and Lymnaea natalensis snails are the intermediate hosts of schistosomiasis and fasciolosis. The aim of the present study is to evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against these snails and how it affected its tissues and the biological system. Chlorophyllin was extracted from deep-frozen Moringa oleifera leaves, and then it was transformed into water-soluble chlorophyllin. The present results showed that it had a molluscicidal activity on B. alexandrina snails (LC50 17.6 mg/l; LC90 20.9 mg/l) and L. natalensis snails (LC50 4.3 mg/l; LC90 6.8 mg/l). Exposing B. alexandrina snails to the sublethal concentrations (LC0, LC10, and LC25) resulted in a significant reduction in their survival rates. Regarding its effect on biochemical parameters, chlorophyllin significantly reduced the acetylcholinesterase activity, protein content, and alkaline and acid phosphatase activity in B. alexandrina nervous tissue compared to the control group. Histopathological changes occurred in the digestive gland of treated B. alexandrina snails where cells lost their nuclei, vacuolated, degenerated, and ruptured, and the lumen increased. Photosynthesizing materials like chlorophyllin are new approaches to control schistosomiasis and fasciolosis in developing countries by affecting their intermediate host. These materials were cheap and environmentally safe to replace the synthetic molluscicides for snail control.

Molluscicidal effectiveness of Luo-Wei, a novel plant-derived molluscicide, against Oncomelania hupensis, Biomphalaria alexandrina and Bulinus truncatus.

BACKGROUND: Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis. Some plant extracts have shown obvious molluscicidal activity, and a new compound Luo-Wei, also named tea-seed distilled saponin (TDS), was developed based on the saponins extracted from Camellia oleifera seeds. We aimed to test the molluscicidal activity of 4% TDS against the intermediate host snails in China and Egypt, and evaluate its environmental safety to non-target organisms. METHODS: In the laboratory, Oncomelania hupensis, Biomphalaria alexandrina and Bulinus truncatus were exposed to 4% TDS, and the median lethal concentration (LC50) was estimated at 24, 48 and 72 h. In the field, snail mortalities were assessed 1, 2, 3 and 7 d post-immersion with 2.5 g/m3 4% TDS and 1, 3, 7 and 15 d post-spraying with 5 g/m2 4% TDS. In addition, the acute toxicity of 4% TDS to Japanese quail (Coturnix japonica), zebrafish (Brachydanio rerio) and freshwater shrimp (Macrobrachium nipponense) was assessed by estimations of LC50 or median lethal dose (LD50). RESULTS: In the laboratory, the LC50 values of 4% TDS for O. hupensis were 0.701, 0.371 and 0.33 mg/L at 24, 48 and 72 h, respectively, and 4% TDS showed a 1.975 mg/L [corrected] 24 h LC50 against B. alexandrina, and a 1.396 mg/L 24 h LC50 against B. truncatus. Across all study regions, the pooled mortalities of O. hupensis were 72, 86, 94 and 98% at 1, 2, 3 and 7 d, following field immersion of 4% TDS at a dose of 2.5 g/m3, and were 69, 77, 85 and 88% at 1, 3, 7 and 15 d, following field spraying at 5 g/m2, respectively. 4% TDS had moderate toxicity to Japanese quail (7 d LD50 > 60 mg/kg) and to shrimp (96 h LC50 = 6.28 mg/L; 95% CI: 3.53-11.2 mg/L), whereas its toxicity to zebrafish was high (96 h LC50 = 0.15 mg/L; 95% CI: 0.14-0.17 mg/L). CONCLUSIONS: 4% TDS is active against O. hupensis, B. alexandrina and B. truncatus under laboratory and field conditions, and it may be a candidate molluscicide of plant origin.

Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts)

BACKGROUND This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

Schistosomiasis: Snail-vector control, molecular modelling and dynamic studies of bioactive N-acetylglycoside saponins from Tetrapleura tetraptera.

Schistosomiasis, a chronic neglected tropical disease caused by the Schistosoma spp. parasite, is associated with disabling patient symptoms. The new focus of the WHO roadmap on 'transmission control, wherever possible' offers drug development opportunities for intermediate-host control to prevent human-to-snail-to-human parasite transmission. Reports on the analysis of the impact of 'chemical-based mollusciciding' have concluded that constant application of molluscicides may contribute significantly towards the elimination of schistosomiasis in endemic areas. In South-Western Nigeria, Tetrapleura tetraptera is a tree whose fruit has been widely used in snail vector control. The presence of molluscicidal N-acetyl triterpene glycosides in the fruit has been reported. In this study, a bioactivity-directed fractionation of the fruit extract was performed to isolate the most potent molluscicidal saponin from the fruit. In an attempt to provide mechanistic insight into the observed activity, in silico screening was performed, profiling the molluscicidal N-acetyl triterpene glycosides reported from the fruit against two potential therapeutic targets in the mollusk used, NADH-ubiquinone oxidoreductase (NAD1) and retinoid X receptor. The docking predicted binary complexes of the saponins, which were subjected to explicit solvent conformational sampling from which patterns of structural stability were obtained. The binding energies alone did not account for the potency of the saponins indicating the influence of other factor like pharmacokinetic parameters. The study concluded that there is a preferential suitability of ND1's MWFE site for the rational design and development of novel molluscicidal agents.

Molluscicidal impacts of Anagallis arvensis aqueous extract on biological, hormonal, histological and molecular aspects of Biomphalaria alexandrina snails.

Controlling of Biomphalaria alexandrina snails by plant molluscicides is the cornerstone in treating schistosomiasis in Egypt. The objective of this study is, to evaluate the molluscicidal activity of the aqueous leaves extract of Anagallis arvensis against B. alexandrina snails. The present results showed that this aqueous extract was lethal for B. alexandrina snails at (LC50 37.9 mg/l; LC90 48.3 mg/l), and caused reduction in survival; reproductive rates and hormonal activity (testosterone (T) and 17ß-estradiol (E)) of these snails. Histopathological changes occurred in the hermaphrodite glands of snails exposed to the sub lethal concentrations of this aqueous extract are detected, where, there were degeneration in both eggs and sperms and there were losses of connective tissues between acini. The present investigation revealed that this plant had a genotoxic effect especially with its concentration (LC10 and LC25), where, the length of olive tail moment was significantly increased than control group. These observations prove the potent molluscicidal activity of aqueous leaves extract of A. arvensis against the intermediate hosts of Schistosoma mansoni and provide natural biodegradable resources for snails' molluscicidal agents.

Interrupting seasonal transmission of Schistosoma haematobium and control of soil-transmitted helminthiasis in northern and central Côte d'Ivoire: a SCORE study protocol.

BACKGROUND: To achieve a world free of schistosomiasis, the objective is to scale up control and elimination efforts in all endemic countries. Where interruption of transmission is considered feasible, countries are encouraged to implement a comprehensive intervention package, including preventive chemotherapy, information, education and communication (IEC), water, sanitation and hygiene (WASH), and snail control. In northern and central Côte d'Ivoire, transmission of Schistosoma haematobium is seasonal and elimination might be achieved. In a cluster-randomised trial, we will assess different treatment schemes to interrupt S. haematobium transmission and control soil-transmitted helminthiasis over a 3-year period. We will compare the impact of (i) arm A: annual mass drug administration (MDA) with praziquantel and albendazole before the peak schistosomiasis transmission season; (ii) arm B: annual MDA after the peak schistosomiasis transmission season; (iii) arm C: two yearly treatments before and after peak schistosomiasis transmission; and (iv) arm D: annual MDA before peak schistosomiasis transmission, coupled with chemical snail control using niclosamide. METHODS/DESIGN: The prevalence and intensity of S. haematobium and soil-transmitted helminth infections will be assessed using urine filtration and Kato-Katz thick smears, respectively, in six administrative regions in northern and central parts of Côte d'Ivoire. Once a year, urine and stool samples will be collected and examined from 50 children aged 5-8 years, 100 children aged 9-12 years and 50 adults aged 20-55 years in each of 60 selected villages. Changes in S. haematobium and soil-transmitted helminth prevalence and intensity will be assessed between years and stratified by intervention arm. In the 15 villages randomly assigned to intervention arm D, intermediate host snails will be collected three times per year, before niclosamide is applied to the selected freshwater bodies. The snail abundance and infection rates over time will allow drawing inference on the force of transmission. DISCUSSION: This cluster-randomised intervention trial will elucidate whether in an area with seasonal transmission, the four different treatment schemes can interrupt S. haematobium transmission and control soil-transmitted helminthiasis. Lessons learned will help to guide schistosomiasis control and elimination programmes elsewhere in Africa. TRIAL REGISTRATION: ISRCTN ISRCTN10926858 . Registered 21 December 2016. Retrospectively registered.

Apropos: critical analysis of molluscicide application in schistosomiasis control programs in Brazil.

Schistosomiasis is a snail-transmitted infectious disease affecting over 200 million people worldwide. Snail control has been recognized as an effective approach to interrupt the transmission of schistosomiasis, since the geographic distribution of this neglected tropical disease is determined by the presence of the intermediate host snails. In a recent Scoping Review published in Infectious Diseases of Poverty, Coelho and Caldeira performed a critical review of using molluscicides in the national schistosomiasis control programs in Brazil. They also described some chemical and plant-derived molluscicides used in China. In addition to the molluscicides described by Coelho and Caldeira, a large number of chemicals, plant extracts and microorganisms have been screened and tested for molluscicidal actions against Oncomelania hupensis, the intermediate host of Schistosoma japonicum in China. Here, we presented the currently commercial molluscicides available in China, including 26% suspension concentrate of metaldehyde and niclosamide (MNSC), 25% suspension concentrate of niclosamide ethanolamine salt (SCNE), 50% niclosamide ethanolamine salt wettable powder (WPN), 4% niclosamide ethanolamine salt dustable powder (NESP), 5% niclosamide ethanolamine salt granule (NESG) and the plant-derived molluscicide "Luowei". These molluscicides have been proved to be active against O. hupensis in both laboratory and endemic fields, playing an important role in the national schistosomiasis control program of China. Currently, China is transferring its successful experiences on schistosomiasis control to African countries. The introduction of Chinese commercial molluscicides to Africa, with adaptation to local conditions, may facilitate the progress towards the elimination of schisosomiasis in Africa.

A call to strengthen the global strategy against schistosomiasis and soil-transmitted helminthiasis: the time is now.

In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience has yielded crucial knowledge on the control and elimination of these helminthiases. However, the global strategy has remained largely unchanged since the original 2001 WHA resolution and associated WHO guidelines on preventive chemotherapy. In this Personal View, we highlight recent advances that, taken together, support a call to revise the global strategy and guidelines for preventive chemotherapy and complementary interventions against schistosomiasis and soil-transmitted helminthiasis. These advances include the development of guidance that is specific to goals of morbidity control and elimination of transmission. We quantify the result of forgoing this opportunity by computing the yearly disease burden, mortality, and lost economic productivity associated with maintaining the status quo. Without change, we estimate that the population of sub-Saharan Africa will probably lose 2·3 million disability-adjusted life-years and US$3·5 billion of economic productivity every year, which is comparable to recent acute epidemics, including the 2014 Ebola and 2015 Zika epidemics. We propose that the time is now to strengthen the global strategy to address the substantial disease burden of schistosomiasis and soil-transmitted helminthiasis.

A new global strategy for the elimination of schistosomiasis.

Mass drug administration utilising a single oral dose of 40mg/kg of praziquantel (PZQ) has been endorsed and advocated by the World Health Organisation (WHO) for the global control and elimination of schistosomiasis. However, this strategy is failing primarily because the drugs are not getting to the people who need them the most. The current global coverage is 20%, the drug compliance rate is less than 50%, and the drug efficacy is approximately 50%. Thus in reality, only about 5% of the reservoir human population is actually receiving intermittent chemotherapy. Despite claims that more of the drug will soon be made available the current strategy is inherently flawed and will not lead to disease elimination. We discuss the many practical issues related to this global strategy, and advocate for an integrated control strategy targeting the life cycle and the most at-risk. Moreover, we discuss how an integrated control package for schistosomiasis should fit within a larger integrated health package for rural and remote villages in the developing world. A holistic health system approach is required to achieve sustainable control and ultimately disease elimination.