[Assessment of schistosomiasis transmission risk along the Yangtze River basin after the flood disaster in 2020].

OBJECTIVE: To evaluate the impact of the flood disaster on schistosomiasis transmission along the Yangtze River basin in 2020, so as to provide insights into schistosomiasis prevention and control in flood-affected areas. METHODS: The data pertaining to the endemic situation of schistosomiasis were collected from 5 provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu from 2013 to 2019, including Schistosoma japonicum infections in humans and livestock and snail distribution, and the warning water levels and actual water status were collected in water regions locating in these 5 provinces. The cumulative numbers of S. japonicum egg-positive individuals and bovines during the period from 2013 to 2019, the area of snail habitats in 2019 and the water level on July 12, 2020 were estimated at a county level and employed as parameters for classification of schistosomiasis transmission risk. Then, the cumulative value of each risk index was calculated to assess the risk of schistosomiasis transmission risk. RESULTS: After the flood disaster along the Yangtze River basin in 2020, there were 10, 5 and 9 counties (districts) at high risk of schistosomiasis transmission in 5 provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu based on number of egg-positive individuals, number of egg-positive bovines and snail distribution, respectively. Based on comprehensive risk indices, there were 10 (8 in Dongting Lake regions of Hunan Province and 2 in Poyang Lake regions of Jiangxi Province) and 15 counties (districts) (4 in Hubei Province, 7 in Hunan Province and 4 in Jiangxi Province) identified at grades 5 and 4 risk of schistosomiasis transmission. CONCLUSIONS: Dongting Lake regions and Poyang Lake regions are the most severely flood-affected schistosomiasis-endemic foci of China in 2020, and the flood disaster may facilitate the transmission of schistosomiasis in affected areas. Therefore, schistosomiasis control requires to be intensified after the flood disaster to prevent the rebound of the disease.

[Assessment of schistosomiasis transmission risk in Nanjian County of Yunnan Province in 2019].

OBJECTIVE: To assess the schistosomiasis transmission risk in Nanjing County, so as to provide the scientific evidence for the development of the schistosomiasis control strategy and consolidation of the control achievements. METHODS: On May 2019, the Deqiu Village in Deqiu Town and Baiyun Village in Nanjing Town of Yunnan Province, where schistosomiasis were historically relatively highly endemic, were selected to assess the risk of transmission of schistosomiasis by means of a retrospective review of the data pertaining to the historical endemic situation and schistosomiasis control, combined with a cross-sectional survey of snail and wild feces distribution. RESULTS: During the period between 2017 and 2018, the mean sero-prevalence rates of Schistosoma japonicum infections were 6.76% (202/2 990) and 2.86% (142/4 971) in humans and 0 (0/1 160) and 10.65% (31/291) in bovines in Deqiu and Baiyun villages of Nanjian County, respectively; however, no egg-positives were identified; in addition, there were 21.06 hm2 snail habitats found, but no S. japonicum infections were detected in snails. In 2019, there was 6.17 hm2 snail habitats detected, with 2.17% (245/11 298) occurrence of frames with snails and a 0.06 snails/0.1 m2 density of living snails; however, no positives for nucleic acid detection were seen in snails; among the 136 wild fecal samples captures from 23 settings, no S. japonicum infections were identified. CONCLUSIONS: The risk of schistosomiasis transmission remains at a low level in Nanjian County; however, the factors affecting the transmission of schistosomiasis have not been completed eliminated. The integrated schistosomiasis control strategy with an emphasis on the control of the source of S. japonicum infections requires to be reinforced to consolidate the control achievements.

Survey of Schistosomiasis in Saint Lucia: Evidence for Interruption of Transmission.

Saint Lucia at one time had levels of schistosomiasis prevalence and morbidity as high as many countries in Africa. However, as a result of control efforts and economic development, including more widespread access to sanitation and safe water, schistosomiasis on the island has practically disappeared. To evaluate the current status of schistosomiasis in Saint Lucia, we conducted a nationally representative school-based survey of 8-11-year-old children for prevalence of Schistosoma mansoni infections using circulating antigen and specific antibody detection methods. We also conducted a questionnaire about available water sources, sanitation, and contact with fresh water. The total population of 8-11-year-old children on Saint Lucia was 8,985; of these, 1,487 (16.5%) provided urine for antigen testing, 1,455 (16.2%) provided fingerstick blood for antibody testing, and 1,536 (17.1%) answered the questionnaire. Although a few children were initially low positives by antigen or antibody detection methods, none could be confirmed positive by follow-up testing. Most children reported access to clean water and sanitary facilities in or near their homes and 48% of the children reported contact with fresh water. Together, these data suggest that schistosomiasis transmission has been interrupted on Saint Lucia. Additional surveys of adults, snails, and a repeat survey among school-age children will be necessary to verify these findings. However, in the same way that research on Saint Lucia generated the data leading to use of mass drug administration for schistosomiasis control, the island may also provide the information needed for guidelines to verify interruption of schistosomiasis transmission.

The Geshiyaro Project: a study protocol for developing a scalable model of interventions for moving towards the interruption of the transmission of soil-transmitted helminths and schistosome infections in the Wolaita zone of Ethiopia.

BACKGROUND: National deworming programmes rely almost exclusively on mass drug administration (MDA) to children to control morbidity caused by these parasitic infections. The provision of other interventions, consisting of preventive chemotherapy at high population level coverage together with water, sanitation and hygiene (WaSH) and changes in risk behaviour, should enable sustainable control of soil-transmitted helminths (STH) and schistosomiasis and ultimately interrupt transmission. METHODS/DESIGN: Two interventions will be implemented by the project: (i) community-wide biannual albendazole and annual praziquantel treatment with a target of 80-90% treatment coverage ("expanded MDA"); and (ii) provision of WaSH with behaviour change communication (BCC), within the Wolaita zone, Ethiopia. The project has three study arms: (i) expanded community-wide MDA, WaSH and BCC; (ii) expanded community-wide MDA only; and (iii) annual school-based MDA (the current National STH/schistosomiasis Control Programme). The impact of these interventions will be evaluated through prevalence mapping at baseline and endline (after four rounds of MDA), combined with annual longitudinal parasitological surveillance in defined cohorts of people to monitor trends in prevalence and reinfection throughout the project. Treatment coverage and individual compliance to treatment will be monitored by employing fingerprint biometric technology and barcoded identification cards at treatment. WaSH utilisation will be evaluated through school and household level observations and annual WaSH assessment survey. Complementary qualitative surveys will explore practices, cultural and social drivers of risk behaviours, uptake of WaSH and treatment, and assessing the impact of the BCC. DISCUSSION: The study has the potential to define an 'End Game' for STH and schistosomiasis programmes through provision of multiple interventions. Interrupting transmission of these infections would eliminate the need for long-term repeated MDA, lead to sustained health improvements in children and adults, thereby allowing health systems to focus on other disease control priorities.

Vaccination or mass drug administration against schistosomiasis: a hypothetical cost-effectiveness modelling comparison.

BACKGROUND: Schistosomiasis is a neglected tropical disease, targeted by the World Health Organization for reduction in morbidity by 2020. It is caused by parasitic flukes that spread through contamination of local water sources. Traditional control focuses on mass drug administration, which kills the majority of adult worms, targeted at school-aged children. However, these drugs do not confer long-term protection and there are concerns over the emergence of drug resistance. The development of a vaccine against schistosomiasis opens the potential for control methods that could generate long-lasting population-level immunity if they are cost-effective. METHODS: Using an individual-based transmission model, matched to epidemiological data, we compared the cost-effectiveness of a range of vaccination programmes against mass drug administration, across three transmission settings. Health benefit was measured by calculating the heavy-intensity infection years averted by each intervention, while vaccine costs were assessed against robust estimates for the costs of mass drug administration obtained from data. We also calculated a critical vaccination cost, a cost beyond which vaccination might not be economically favorable, by benchmarking the cost-effectiveness of potential vaccines against the cost-effectiveness of mass drug administration, and examined the effect of different vaccine protection durations. RESULTS: We found that sufficiently low-priced vaccines can be more cost-effective than traditional drugs in high prevalence settings, and can lead to a greater reduction in morbidity over shorter time-scales. MDA or vaccination programmes that target the whole community generate the most health benefits, but are generally less cost-effective than those targeting children, due to lower prevalence of schistosomiasis in adults. CONCLUSIONS: The ultimate cost-effectiveness of vaccination will be highly dependent on multiple vaccine characteristics, such as the efficacy, cost, safety and duration of protection, as well as the subset of population targeted for vaccination. However, our results indicate that if a vaccine could be developed with reasonable characteristics and for a sufficiently low cost, then vaccination programmes can be a highly cost-effective method of controlling schistosomiasis in high-transmission areas. The population-level immunity generated by vaccination will also inevitably improve the chances of interrupting transmission of the disease, which is the long-term epidemiological goal.

[Risk assessment of schistosomiasis transmission in Chuxiong City of Yunnan Province].

OBJECTIVE: To evaluate the potential risk of schistosomiasis transmission so as to provide the evidence for formulating the control strategy. METHODS: Two villages were selected as the investigated sites in Chuxiong City and the risk of schistosomiasis transmission was evaluated by reviewing the data of schistosomiasis epidemic situation and prevention and control work, and carrying out the field survey for Oncomelania hupensis snail status, wild faeces, and schistosome infection of the population from 2015 to 2017. RESULTS: There was 1.49 hm2 area of snail habitats, with an average density of 0.54 snails/0.1 m2. The occurrence rate of frames with snails was 5.41%. No schistosome-infected snails were found. The positive rate of schistosomiasis serological tests of the residents was 3.36%, but the stool examination positive cases were not found. A total of 58 wild faeces samples were collected but no schistosome infested cases were found. The risk levels of schistosomiasis transmission in both villages were Grade III. CONCLUSIONS: Although Chuxiong City has been in a low risk state of schistosomiasis transmission, the density of snails is still high, and there is a risk of infection source importation. In the future, the infection source control and snail control should be strengthened.

[Assessment of schistosomiasis transmission risk after flood damage in Wuhan City].

OBJECTIVE: To assess the schistosomiasis transmission risk after flood damage in Wuhan City. METHODS: Schistosomiasis epidemic villages in Wuhan City were selected by using probability proportional to size sampling (PPS). The field investigations of Oncomelania hupensis snails, the activity of people and cattle on marshland, water infectivity of schistosome, reservoir host infection and wild feces contamination were conducted. I-III levels of risk environments were assessed and treated with appropriate measures. RESULTS: A total of 90 schistosomiasis epidemic villages and 170 environments were monitored. Totally 9 811 snails were dissected but no Schistosoma japonicum infected snails were found. There were significant decreases in the density of snails and the survival rate of living snails after the flood (χ2 = 102.517, t = 4.724, both P < 0.01). Totally 289 pieces of wild feces were captured, and no eggs of S. japonicum were detected. A total of 11 surveillance and forecast sites were detected on water systems, and 221 sentinel mice were placed. After breeding, 219 sentinel mice survived (99.10%), and no schistosome infection was detected. In addition, 1 720 mouse traps were placed in 3 survey sites, and 66 Apodemus agrarius were captured, and no schistosome-infected ones were found. All of the environments were assessed as Grade III. Meanwhile, 5 key schistosomiasis control areas were determined, and no emergency happened after the implementation of comprehensive control interventions. CONCLUSIONS: The risk of schistosomiasis transmission remains low in Wuhan City after the flood, but the potential epidemic risk cannot be ignored.

[Surveillance and risk assessment system of schistosomiasis epidemic focus in Hankou marshland of Wuhan City].

OBJECTIVE: To construct a monitoring and risk assessment system of schistosomiasis epidemic focus in marshland, so as to grasp the risk of schistosomiasis transmission, and to provide the technical support for targeted prevention and control measures. METHODS: The crowd and the risk source of schistosomiasis in Hankou marshland in Wuhan City were monitored to grasp the risk factors of schistosomiasis. The risk level was evaluated by the three-dimensional risk matrix and three-dimensional visualization method. RESULTS: The total numbers of people on holidays and working days were 59 582 and 36 382 persontimes a day respectively in Hankou marshland. Fishing and swimming were the most common ways to contact the river water. The most majority of the people exposed to river water were male (73.9%), retirees (36.1%), local residents (69.7%) and people whose income was 1000 - 3000 yuan per month (52.1%), and the awareness of protection of them was low. In spring, the average density of living Oncomelania hupensis snails was 0.993/0.1 m2, the rat density was 7.72%, and the density of wild feces was 0.78/hm2. In autumn, the average density of living snails was 0.596 /0.1 m2, the rat density was 5.22%, and the density of wild feces was 0.32/hm2. The average density of living snails, the rat density and the density of wild feces were reduced by 39.9%, 32.4% and 59.0% respectively in autumn compared with those in spring. The risk assessment results of three-dimensional matrix showed that part 1 and part 2 were medium risk, part 3 was high risk and part 4 was maximum risk. The risk assessment results of the visualization method showed that the risk level increased from part 1 to part 4, which were basically consistent with the results of the risk matrix. CONCLUSIONS: There is a relatively large risk of schistosome infection in Hankou marshland in 2013. The surveillance and risk assessment system of epidemic focus is feasible and scientific.

Impact and cost-effectiveness of snail control to achieve disease control targets for schistosomiasis.

Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5-20%) and high-prevalence (25-50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, "hot spots" of transmission, and noncompliance to MDA.

Why reinvent the wheel? Lessons in schistosomiasis control from the past.

Schistosomiasis has been of concern to local health authorities for most of the last century, and in spite of a lack of effective chemotherapy, the disease was dealt with quite effectively in many endemic countries by snail control and environmental management [1]. Much of this work was reported in journals prior to the electronic era but, sadly, seems to have been subsequently ignored. For many years, there followed a global hiatus on schistosomiasis control, and much of the local expertise was lost, but many things have changed more recently, mainly with the advent of generic and affordable praziquantel. With the increased availability of this drug, there has been an increasing interest in readdressing schistosomes as well as other neglected tropical diseases (NTDs). The strategic approach for this had been based almost exclusively on chemotherapy. Recently, however, questions arose about this strategy with evidence that chemotherapy alone was not succeeding [2]. Additional strategies were needed, and the "Towards Elimination of Schistosomiasis" (TES) 2017 Conference in Cameroon stressed an integrated PHASE strategy. This was in line with the WHO-NTD and WHO-AFRO 2014-2020 Regional Strategy on NTDs and directed emphasis on transmission control. Subsequently, this emphasis was discussed in a comprehensive review [3] that stressed the importance of such additions to any elimination programme. In reality, this means focusing on the aquatic snail hosts where and when transmission occurs, defining other risk factors such as water contact and latrine design and identifying improved sanitation and health education as essential components for elimination. For schistosomiasis reduction during the mid-20th century, transmission control was used extensively, but these facts are not well reported. Recent reviews have attempted to cover previous research [4,5], but sadly, they have left major knowledge gaps, particularly from Africa. These omissions also occurred in a recent WHO pamphlet on molluscicides [6]. Sadly, search engines used to retrieve information appear to miss much done by 5 African research institutes active from 1950 to 1990. It seems appropriate to take a look back to a time when fieldwork was a focus of research and transmission control was emphasised.

Should we be treating animal schistosomiasis in Africa? The need for a One Health economic evaluation of schistosomiasis control in people and their livestock.

A One Health economic perspective allows informed decisions to be made regarding control priorities and/or implementation strategies for infectious diseases. Schistosomiasis is a major and highly resilient disease of both humans and livestock. The zoonotic component of transmission in sub-Saharan Africa appears to be more significant than previously assumed, and may thereby affect the recently revised WHO vision to eliminate schistosomiasis as a public health problem by 2025. Moreover, animal schistosomiasis is likely to be a significant cost to affected communities due to its direct and indirect impact on livelihoods. We argue here for a comprehensive evaluation of the economic burden of livestock and zoonotic schistosomiasis in sub-Saharan Africa in order to determine if extending treatment to include animal hosts in a One Health approach is economically, as well as epidemiologically, desirable.

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.

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.

RUMOURS, RIOTS AND THE REJECTION OF MASS DRUG ADMINISTRATION FOR THE TREATMENT OF SCHISTOSOMIASIS IN MOROGORO, TANZANIA.

In 2008 in Morogoro region, Tanzania, mass drug administration (MDA) to school-aged children to treat two neglected tropical diseases (NTDs) - urinary schistosomiasis and soil-transmitted helminths - was suspended by the Ministry of Health and Social Welfare after riots broke out in schools where drugs were being administered. This article discusses why this biomedical intervention was so vehemently rejected, including an eyewitness account. As the protest spread to the village where I was conducting fieldwork, villagers accused me of bringing medicine into the village with which to 'poison' the children and it was necessary for me to leave immediately under the protection of the Tanzanian police. The article examines the considerable differences between biomedical and local understandings of one of these diseases, urinary schistosomiasis. Such a disjuncture was fuelled further by the apparent rapidity of rolling out MDA and subsequent failures in communication between programme staff and local people. Rumours of child fatalities as well as children's fainting episodes and illnesses following treatment brought about considerable conjecture both locally and nationally that the drugs had been either faulty, counterfeit, hitherto untested on humans or part of a covert sterilization campaign. The compelling arguments by advocates of MDA for the treatment of NTDs rest on the assumption that people suffering from these diseases will be willing to swallow the medicine. However, as this article documents, this is not always the case. For treatment of NTDs to be successful it is not enough for programmes to focus on economic and biomedical aspects of treatment, rolling out 'one size fits all' programmes in resource-poor settings. It is imperative to develop a biosocial approach: to consider the local social, biological, historical, economic and political contexts in which these programmes are taking place and in which the intended recipients of treatment live their lives. If this is not done, the world's poor will continue to be neglected.

[Surveillance and risk assessment system of schistosomiasis in Jiangsu Province â ¢ Risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City].

OBJECTIVE: To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City, so as to provide evidences for establishing a post-transmission surveillance system for schistosomiasis in marshland regions. METHODS: The water infectivity, floating boatmen and fishermen infection, reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City, including Guangling, Hanjiang, Jiangdu, Yizheng and Development Zone, and the transmission factors and risky characteristics were assessed after interruption of schistosomiasis transmission in marshland regions. RESULTS: A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed, after breeding, their overall survival rate was 99.33%; 1 490 were dissected, with no schistosome infection. Of the 5 576 floating boatmen and fishermen examined, no schistosome infection was observed, and among the 3 566 domestic animals (including 171 cattle, 1 895 sheep and 1 500 pigs), no infections were detected. During the period between January and March, 2016, there were 3 200 mouse traps placed on 8 marshlands, and 62 wild mice were captured from 6 marshlands, with a capture rate of 1.94%, and no schistosomeinfected wild mice were seen. In addition, there were 35 pieces of fresh wild feces captured from 7 marshlands, including 11 pieces of bovine feces (31.43%), 17 pieces of sheep feces (48.57%), 2 pieces of dog feces (5.71%) and 5 pieces of other feces (14.29%), and no infections were detected. CONCLUSIONS: There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However, the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.

[Monitoring of sentinel mice and risk assessment of schistosomiasis transmission in key regions of Yunnan Province in 2014].

OBJECTIVE: To establish and perfect the surveillance and forecast system of schistosomiasis, and timely discover the suspicious high risk environments for preventing the human and livestock from schistosomiasis. METHODS: Eight villages of three counties were selected as survey points. Then, the surveillance and forecast of sentinel mice were carried out in the key water regions. The recovered sentinel mice were dissected in laboratory. The sentinel mouse serum antibodies against schistosome were detected by ELISA, the suspicious water contacts of residents and livestock were investigated and the results were analyzed, and the epidemic risk was assessed. RESULTS: Totally 300 sentinel mice were placed, the recovery rate was 94.67%, and the mortality rate was 8.80%. There were no mice with positive serum antibodies against schistosome, and the results of the dissection of all the sentinel mice were negative. The humans who contacted with the suspicious water were mainly villagers, students, children and fishermen by washing hands and feet, washing vegetables, harvesting, fishing and swimming. The Oncomelania hupensis snail areas, human infection rates, and cattle infection rates were obviously declined in recent 3 years. However, the epidemic risks still existed. CONCLUSION: Although schistosomiasis transmission was effectively controlled in the three counties, the comprehensive control measures still should be strengthened.

Mapping of Schistosomiasis and Soil-Transmitted Helminths in Namibia: The First Large-Scale Protocol to Formally Include Rapid Diagnostic Tests.

BACKGROUND: Namibia is now ready to begin mass drug administration of praziquantel and albendazole against schistosomiasis and soil-transmitted helminths, respectively. Although historical data identifies areas of transmission of these neglected tropical diseases (NTDs), there is a need to update epidemiological data. For this reason, Namibia adopted a new protocol for mapping of schistosomiasis and geohelminths, formally integrating rapid diagnostic tests (RDTs) for infections and morbidity. In this article, we explain the protocol in detail, and introduce the concept of 'mapping resolution', as well as present results and treatment recommendations for northern Namibia. METHODS/FINDINGS/INTERPRETATION: This new protocol allowed a large sample to be surveyed (N = 17,896 children from 299 schools) at relatively low cost (7 USD per person mapped) and very quickly (28 working days). All children were analysed by RDTs, but only a sub-sample was also diagnosed by light microscopy. Overall prevalence of schistosomiasis in the surveyed areas was 9.0%, highly associated with poorer access to potable water (OR = 1.5, P<0.001) and defective (OR = 1.2, P<0.001) or absent sanitation infrastructure (OR = 2.0, P<0.001). Overall prevalence of geohelminths, more particularly hookworm infection, was 12.2%, highly associated with presence of faecal occult blood (OR = 1.9, P<0.001). Prevalence maps were produced and hot spots identified to better guide the national programme in drug administration, as well as targeted improvements in water, sanitation and hygiene. The RDTs employed (circulating cathodic antigen and microhaematuria for Schistosoma mansoni and S. haematobium, respectively) performed well, with sensitivities above 80% and specificities above 95%. CONCLUSION/SIGNIFICANCE: This protocol is cost-effective and sensitive to budget limitations and the potential economic and logistical strains placed on the national Ministries of Health. Here we present a high resolution map of disease prevalence levels, and treatment regimens are recommended.

[Risk assessment of schistosomiasis transmission on rescue workers involved in "Oriental Star shipwreck event"].

OBJECTIVE: To assess the impact of the "Oriental Star shipwreck event" on the risk of schistosomiasis transmission in Jianli County, Hubei Province, so as to provide the evidence for formulating appropriate measures of schistosomiasis prevention and control. METHODS: Based on the field observation and investigation, the data of the on-the-spot rescue and the historical endemic situation of schistosomiasis in Jianli County were collected and analyzed. Meanwhile, the focus group discussion and risk matrix were conducted to assess the risk of schistosome infection of the rescuers. RESULTS: Over 10 000 rescuers participated in the search operation, including the armed police forces, local people, reservists and so on. The armed police forces were the major components, which accounted for 39%. Jianli country was schistosomiasis endemic area with a high infection level in history, but the endemic situation had been mitigated significantly after years of positive prevention and treatment; the schistosome infection rate of population was 0.44% in 2014 and the Oncomelania hupensis snail area was only 6.6 hm2 around the rescue areas in the upstream and downstream. In addition, the snail density was not high, and no infected snails had been found for 11 years. The risk of schistosome infection was in the medium level. CONCLUSIONS: Though there exists the schistosome infection risk in the water area where the accident happened, the probability of occurrence is not high. In order to prevent the outbreak and endemic of schistosomiasis, the protection measures and health education to the rescuers as well as snail control and monitoring, and early-warning should be strengthened.