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Objective: To compare the efficiency of multiple etiological techniques for detection of Schistosoma japonicum infections in wild mice, so as to provide technical supports to assessment of schistosomiasis transmission risk., Methods: Wild mice were captured with baited traps at night in Oncomelania hupensis snail-infested settings in schistosomiasis-endemic foci of Anhui Province from October to November, 2022. S. japonicum infections were detected in wild mice using microscopy of mouse liver tissues, microscopy of mouse mesenteric tissues, microscopy of mouse liver tissue homogenates, miracidial hatching test of mouse liver tissue homogenates, Kato-Katz technique and miracidial hatching test of mouse stool samples alone and in combinations. Identification of S. japonicum eggs or miracidia by any of these six assays was defined as an infection. The sensitivity of six assays alone or in combinations was compared for detection of S. japonicum infections in wild mice., Results: A total of 1 703 wild mice were captured, with 366 wild mice detected positive for S. japonicum (21.49%). There were significant differences in the prevalence of S. japonicum infections in wild mice by six assays ( Q = 529.33, P < 0.001) and in the sensitivity of six assays for detection of S. japonicum infections in wild mice (χ 2 = 527.78, P < 0.001). In addition, the combination of microscopy of mouse liver tissues and mesenteric tissues, combination of microscopy of mouse liver tissues and liver tissue homogenates and combination of microscopy of mouse liver tissues, microscopy of mesenteric tissues, microscopy of liver tissue homogenates and Kato-Katz technique showed 86.61%, 87.16% and 97.27% sensitivities for detection of S. japonicum infections in wild mice, respectively., Conclusions: Diverse etiological assays show various efficiencies for detection of S. japonicum infections in wild mice. Combination of microscopy of mouse liver tissues and microscopy of mesenteric tissues, and combination of microscopy of mouse liver tissues and microscopy of liver tissue homogenates are potential approaches for field detection of S. japonicum infections in wild mice.

Objective: To construct a schistosomiasis transmission risk assessment system in Wuhan City and preliminary evaluate its application effect, so as to promote the rational allocation of schistosomiasis control resources and accelerate the progress towards schistosomiasis elimination., Methods: The schistosomiasis risk assessment indicators were collected through referring schistosomiasis surveillance data of Wuhan City from 2014 to 2020, literature review and expert interviews. Indicators within each criterion and sub-criterion were screened using the Delphi method, and a hierarchical structure model was created based on analytic hierarchy process. Quantitative assignment of each indicator was conducted according to relative importance, and the weight and combination weight of each criterion were calculated in each analytic hierarchy framework to create a schistosomiasis transmission risk assessment system, which was used for the schistosomiasis transmission risk assessment in 12 national schistosomiasis surveillance sites in Wuhan City., Results: A three-level schistosomiasis transmission risk assessment system was preliminarily constructed, which included a target layer, 5 criterion layers and 21 sub-criterion layers. Of all indicators in the criterion layer, transmission route had the highest weight (0.433), followed by source of Schistosoma japonicum infection (0.294); and among all indicators in the sub-criterion layer, S. japonicum infection in Oncomelania hupensis and sentinel mice had the highest combination weight (0.125), followed by prevalence of S. japonicum infection in humans (0.091) and bovines (0.053), snail control by chemical treatment (0.049), positive rate of inquiry examinations (0.048), allocation of schistosomiasis control professionals (0.045), and areas of submerged snail-infested settings (0.041). Of the 12 national schistosomiasis surveillance sites in Wuhan City, there were 5 sites with weights of > 0.8, 4 sites with weights of 0.6 to 0.8, and 3 sites with weights of < 0.6 in 2020., Conclusions: A schistosomiasis transmission risk assessment system has been constructed based on analytic hierarchy process in Wuhan City, which may provide a evidence-based basis for health resource allocation and decision-making for schistosomiasis control.

Bovines are important reservoir hosts of schistosomiasis, placing humans and animals in rice fields areas at risk of infection. This study reported the prevailing infection of zoonotic parasites from bovine feces in the rice fields adjacent to Lake Mainit, Philippines. Formalin Ethyl Acetate Sedimentation was performed on 124 bovine fecal samples from rice fields and documented eggs and cysts from seven parasites: Schistosoma japonicum, Fasciola gigantica, Ascaris sp., Strongyloides sp., Balantidium coli, coccidian oocyst and a hookworm species. Among these parasites, F. gigantica harboured the highest infection with a 100% prevalence rate, followed by hookworms (51.61%), B. coli (30.64%) and S. japonicum (12.09%), respectively. The intensity of infection of S. japonicum eggs per gram (MPEG = 4.19) among bovines is categorized as ‘light.’ Bovine contamination index (BCI) calculations revealed that, on average, infected bovines in rice fields excrete 104 750 S. japonicum eggs daily. However, across all ricefield stations, bovines were heavily infected with fascioliasis with BCI at 162 700 F. gigantica eggs per day. The study reports that apart from the persistent cases of schistosomiasis in the area, bovines in these rice fields are also heavily infected with fascioliasis. The study confirms the critical role of bovines as a reservoir host for continued infection of schistosomiasis, fascioliasis and other diseases in the rice fields of Lake Mainit. Immediate intervention to manage the spread of these diseases in bovines is recommended.

This report presented the endemic status of schistosomiasis and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance program in the People's Republic of China in 2022. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to maintain the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2022. A total of 452 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2022, with 27 434 endemic villages covering 73 424 400 people at risk of infections. Among the 452 endemic counties (cities, districts), 75.89% (343/452), 23.45% (106/452) and 0.66% (3/452) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. In 2022, 4 317 356 individuals received serological tests for schistosomiasis, and 62 228 were sero-positive. A total of 208 646 individuals received stool examinations for schistosomiasis, with one positive and another two cases positive for urine microscopy, and these three 3 cases were imported schistosomiasis patients from Africa. There were 28 565 cases with advanced schistosomiasis documented in China by the end of 2022. Oncomelania hupensis snail survey was performed in 18 891 endemic villages in China in 2022 and O. hupensis snails were found in 6 917 villages (36.62% of all surveyed villages), with 8 villages identified with emerging snail habitats. Snail survey was performed at an area of 655 703.01 hm 2 and 183 888.60 hm 2 snail habitats were found, including 110.58 hm 2 emerging snail habitats and 844.35 hm 2 re-emerging snail habitats. There were 477 200 bovines raised in the schistosomiasis endemic areas of China in 2022, and 113 946 bovines received serological examinations for schistosomiasis, with 204 sero-positives detected. Among the 131 715 bovines received stool examinations, no positives were identified. In 2022, there were 19 726 schistosomiasis patients receiving praziquantel chemotherapy, and expanded chemotherapy was performed in 714 465 person-time for humans and 234 737 herd-time for bovines in China. In 2022, snail control with chemical treatment was performed at an area of 119 134.07 hm 2 , and the actual area of chemical treatment was 65 825.27 hm 2 , while environmental improvements were performed at an area of 1 163.96 hm 2 . Data from the national schistosomiasis surveillance program of China showed that the mean prevalence of Schistosoma japonicum infections was both zero in humans and bovines in 2022, and no S. japonicum infection was detected in O. hupensis snails. These data demonstrated that the endemic status of schistosomiasis continued to decline in China in 2022, with 3 confirmed schistosomiasis patients that had a foreign nationality and all imported from Africa, and the areas of snail habitats remained high. Further improvements in the construction of the schistosomaisis surveillance and forecast system, and reinforcement of O. hupensis survey and control are required to prevent the re-emerging schistosomiasis.

Background: Although the presence of intermediate snails is a necessary condition for local schistosomiasis transmission to occur, using them as surveillance targets in areas approaching elimination is challenging because the patchy and dynamic quality of snail host habitats makes collecting and testing snails labor-intensive. Meanwhile, geospatial analyses that rely on remotely sensed data are becoming popular tools for identifying environmental conditions that contribute to pathogen emergence and persistence., Methods: In this study, we assessed whether open-source environmental data can be used to predict the presence of human Schistosoma japonicum infections among households with a similar or improved degree of accuracy compared to prediction models developed using data from comprehensive snail surveys. To do this, we used infection data collected from rural communities in Southwestern China in 2016 to develop and compare the predictive performance of two Random Forest machine learning models: one built using snail survey data, and one using open-source environmental data., Results: The environmental data models outperformed the snail data models in predicting household S. japonicum infection with an estimated accuracy and Cohen's kappa value of 0.89 and 0.49, respectively, in the environmental model, compared to an accuracy and kappa of 0.86 and 0.37 for the snail model. The Normalized Difference in Water Index (an indicator of surface water presence) within half to one kilometer of the home and the distance from the home to the nearest road were among the top performing predictors in our final model. Homes were more likely to have infected residents if they were further from roads, or nearer to waterways., Conclusion: Our results suggest that in low-transmission environments, leveraging open-source environmental data can yield more accurate identification of pockets of human infection than using snail surveys. Furthermore, the variable importance measures from our models point to aspects of the local environment that may indicate increased risk of schistosomiasis. For example, households were more likely to have infected residents if they were further from roads or were surrounded by more surface water, highlighting areas to target in future surveillance and control efforts., (© 2023. The Author(s).)

Objective: Schistosomiasis is a neglected tropical parasitic disease caused by blood flukes of the genus Schistosoma. Schistosoma japonicum is zoonotic in China, the Philippines, and Indonesia, with bovines acting as major reservoirs of human infection. The primary objective of the trial was to examine the impact of a combination of human mass chemotherapy, snail control through mollusciciding, and SjCTPI bovine vaccination on the rate of human infection., Methods: A 5-year phase IIIa cluster randomized control trial was conducted among 18 schistosomiasis-endemic villages comprising 18,221 residents in Northern Samar, The Philippines., Results: Overall, bovine vaccination resulted in a statistically significant decrease in human infection (relative risk [RR] = 0.75; 95% confidence interval [CI] = 0.69 to 0.82) across all trial follow-ups. The best outcome of the trial was when bovine vaccination was combined with snail mollusciciding. This combination resulted in a 31% reduction (RR = 0.69; 95% CI = 0.61 to 0.78) in human infection., Conclusion: This is the first trial to demonstrate the effectiveness of a bovine vaccine for schistosomiasis in reducing human schistosome infection. The trial is registered with Australian New Zealand Clinical Trials Registry (ACTRN12619001048178)., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: To investigate the changing trends in the prevalence of schistosomiasis in Anhui Province from 2004 to 2020, so as to provide the evidence for formulating the schistosomiasis elimination strategy in the province., Methods: The epidemiological data of schistosomiasis in Anhui Province from 2004 to 2020 were collected, and the trends in the endemic status of schistosomiasis were analyzed using a Joinpoint regression model. The trends in the prevalence of Schistosoma japonicum infections in humans, bovines and Oncomelania hupensis were measured in Anhui Province from 2004 to 2020 using average annual percent change (AAPC), and the correlations among the changing trends in the prevalence of S. japonicum infections in humans, bovines and O. hupensis snail status were evaluated using Pearson correlation analysis., Results: The prevalence of S.japonicum human infections continued to decline in Anhui Province from 2004 to 2020, with an annual mean decline of 14.8% [AAPC = -14.8%, 95% confidential interval ( CI ): (-18.9%, -10.5%), P < 0.01]. The prevalence of S. japonicum infections continued to decline in bovines in Anhui Province from 2004 to 2015 [AAPC = -31.3%, 95% CI : (-35.1%, -27.2%), P < 0.01], and was 0 for 5 successive years from 2016 to 2020. During the period from 2004 to 2020, there was an annual mean decline of 0.7% in areas of snail habitats [AAPC = -0.7%, 95% CI : (-1.2%, 0.3%), P < 0.05] and an annual mean decline of 9.2% in the density of living snails [AAPC = -9.2%, 95% CI : (-18.3%, 1.0%), P = 0.08] in Anhui Province from 2004 to 2020, and an annual mean decline of 35.6% was found in the density of S. japonicum -infected snails [AAPC = -35.6%, 95% CI : (-49.2%, -18.3%), P < 0.01] from 2004 to 2012, with no infected snails detected in Anhui Province from 2013 to 2020. There were significant correlations in the prevalence of S. japonicum infections between humans and bovines ( r = 0.959, P < 0.01), between the prevalence of S. japonicum human infections and the density of S. japonicum -infected snails ( r = 0.823, P < 0.01) and between the prevalence of S. japonicum infections in bovines and the density of S. japonicum -infected snails ( r = 0.902, P < 0.01)., Conclusions: The prevalence of S. japonicum infections appeared a decline in humans, bovines and O. hupensis in Anhui Province from 2004 to 2020, and significant correlations were found among the changing trends in the prevalence of S. japonicum human infections, the prevalence of S. japonicum bovine infections and the density of S. japonicum -infected O. hupensis snails. Because of a minor decline in the area of snail habitats and widespread distribution of O. hupensis , however, there is still a risk of schistosomiasis transmission, and precision control for schistosomiasis remains to be reinforced in Anhui Province.

Objective: To investigate the prevalence of Schistosoma japonicum infection in wild mice in Shitai County, Anhui Province, so as to provide insights into precise control of the source of S. japonicum infections., Methods: Wild mice were captured using the trapping method for three successive nights at snail-infested settings from Jitan Village of Jitan Township, and Shiquan Village and Xibai Village of Dingxiang Township, Shitai County, Anhui Province in June and October, 2018. All trapped wild mice were sacrificed and liver and mesenteric vein specimens were collected for detection of S. japonicum eggs using microscopy, while the fecal samples in mouse intestines were collected for identification of S. japonicum infections using Kato-Katz technique. In addition, the population density of trapped wild mice was estimated and the prevalence of S. japonicum infection was calculated in trapped wild mice., Results: A total of 376 wild mice were trapped from three villages in Shitai County. The population density of trapped wild mice was 9.1% (376/4 124), and the prevalence of S. japonicum infection was 24.2% (91/376) in trapped wild mice. The highest prevalence of S. japonicum infection was detected in Shiquan Village of Dingxiang Township (30.1%), and the lowest prevalence was seen in Xibai Village of Dingxiang Township; however, there was no significant difference in the prevalence of S. japonicum infection in trapped wild mice among three villages (χ 2 = 4.111, P > 0.05). In addition, there was no significant difference in the prevalence of S. japonicum infection in wild mice captured between on June (26.8%, 34/127) and October (22.9%, 57/249) (χ 2 = 0.690, P = 0.406). The trapped wild mice included 6 species, including Rattus norvegicus, Niviventer niviventer, R. losea, Apodemus agrarius, Mus musculus and N. coning, and the two highest prevalence of S. japonicum infection was detected in R. losea (34.9%, 22/63) and R. norvegicus (31.2%, 44/141)., Conclusions: The prevalence of S. japonicum infections is high in wild mice in Shitai County, and there is a natural focus of schistosomiasis transmission in Shitai County.

This report presented the endemic status of schistosomiasis and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance sites in the People's Republic of China at a national level in 2021. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2021. A total of 451 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2021, with 27 571 endemic villages covering 73 250 600 people at risk of infections. Among the 451 endemic counties (cities, districts), 75.17% (339/451), 22.17% (100/451) and 2.66% (12/451) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2021, 29 037 cases with advanced schistosomiasis were documented in China. In 2021, 4 405 056 individuals received serological tests and 72 937 were sero-positive. A total of 220 629 individuals received stool examinations and 3 were positive. In 2021, snail survey was performed in 19 291 endemic villages in China and Oncomelania snails were found in 7 026 villages, accounting for 36.42% of all surveyed villages, with 12 villages identified with emerging snail habitats. Snail survey was performed at an area of 686 574.46 hm 2 and 191 159.91 hm 2 snail habitats were found, including 1 063.08 hm 2 emerging snail habitats and 5 113.87 hm 2 reemerging snail habitats. In 2021, 525 878 bovines were raised in the schistosomiasis endemic areas of China, and 115 437 received serological examinations, with 231 positives detected. Among the 128 719 bovines received stool examinations, no positives were identified. In 2021, there were 19 927 schistosomiasis patients receiving praziquantel chemotherapy, and 729 113 person-time individuals and 256 913 herd-time bovines were given expanded chemotherapy. In 2021, snail control with chemicals was performed in 117 372.74 hm 2 snail habitats, and the actual area of chemical treatment was 65 640.50 hm 2 , while environmental improvements were performed in snail habitats covering an area of 1 244.25 hm 2 . Data from the national schistosomiasis surveillance sites of China showed that the mean prevalence of Schistosoma japonicum infections were both zero in humans and bovines in 2021, and no S. japonicum infection was detected in snails. The results demonstrate that the overall endemic status of schistosomiasis remained at a low level in China in 2021; however, the progress towards schistosomiasis elimination was slowed and the areas of snail habitats rebounded mildly. Strengthening researches on snail diffusion and control, and improving schistosomiasis surveillance and forecast are recommended to prevent reemerging schistosomiasis.

In China, bovines are believed to be the most common animal source of human schistosomiasis infections, though little is known about what factors promote bovine infections. The current body of literature features inconsistent, and sometimes contradictory results, and to date, few studies have looked beyond physical characteristics to identify the broader environmental conditions that predict bovine schistosomiasis. Because schistosomiasis is a sanitation-related, water-borne disease transmitted by many animals, we hypothesised that several environmental factors - such as the lack of improved sanitation systems, or participation in agricultural production that is water-intensive - could promote schistosomiasis infection in bovines. Using data collected as part of a repeat cross-sectional study conducted in rural villages in Sichuan, China from 2007 to 2016, we used a Random Forests, machine learning approach to identify the best physical and environmental predictors of bovine Schistosoma japonicum infection. Candidate predictors included: (i) physical/biological characteristics of bovines, (ii) human sources of environmental schistosomes, (iii) socio-economic indicators, (iv) animal reservoirs, and (v) agricultural practices. The density of bovines in a village and agricultural practices such as the area of rice and dry summer crops planted, and the use of night soil as an agricultural fertilizer, were among the top predictors of bovine S. japonicum infection in all collection years. Additionally, human infection prevalence, pig ownership and bovine age were found to be strong predictors of bovine infection in at least 1 year. Our findings highlight that presumptively treating bovines in villages with high bovine density or human infection prevalence may help to interrupt transmission. Furthermore, village-level predictors were stronger predictors of bovine infection than household-level predictors, suggesting future investigations may need to apply a broad ecological lens to identify potential underlying sources of persistent transmission., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen., Methods: The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years., Results: A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% ( χ 2 = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 ( χ 2 = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline ( Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05)., Conclusions: The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.

Background: Due to sustained control activities, the prevalence of Schistosoma japonicum infection in humans, livestock and snails has decreased significantly in P. R. China, and the target has shifted from control to elimination according to the Outline of Healthy China 2030 Plan. Applying highly sensitive methods to explore the presence of S. japonicum infection in its intermediate host will benefit to assess the endemicity or verify the transmission interruption of schistosomiasis accurately. The aim of this study was to access the presence of S. japonicum infection by a loop-mediated isothermal amplification (LAMP) method through a 5-year longitudinal study in five lake provinces along the Yangtze River., Methods: Based on previous epidemiological data, about 260 villages with potential transmission risk of schistosomiasis were selected from endemic counties in five lake provinces along the Yangtze River annually from 2015 to 2019. Snail surveys were conducted in selected villages by systematic sampling method and/or environmental sampling method each year. All live snails collected from field were detected by microscopic dissection method, and then about one third of them were detected by LAMP method to assess the presence of S. japonicum infection with a single blind manner. The infection rate and nucleic acid positive rate of schistosomes in snails, as well as the indicators reflecting the snails' distribution were calculated and analyzed. Fisher's exact test was used to examine any change of positive rate of schistosomes in snails over time., Results: The 5-year survey covered 94,241 ha of environment with 33,897 ha of snail habitats detected accumulatively. Totally 145.3 ha new snail habitats and 524.4 ha re-emergent snail habitats were found during 2015-2019. The percentage of frames with snails decreased from 5.93% [45,152/761,492, 95% confidence intervals (CI): 5.88-5.98%] in 2015 to 5.25% (30,947/589,583, 95% CI: 5.19-5.31%) in 2019, while the mean density of living snails fluctuated but presented a downward trend generally from 0.20 snails/frame (155,622/761,492, 95% CI: 0.17-0.37) in 2015 to 0.13 snails/frame (76,144/589,583, 95% CI: 0.11-0.39) in 2019. A total of 555,393 live snails were collected, none of them was positive by dissection method. Totally 17 pooling snail samples were determined as positives by LAMP method among 8716 pooling samples with 174,822 of living snails, distributed in 12 villages of Hubei, Hunan, Jiangxi and Anhui provinces. The annual average positive rate was 0.41% (95% CI: 0.13-0.69%) in 2015, 0% in 2016, 0.36% (95% CI: 0.09-0.63%) in 2017, 0.05% (95% CI: 0-0.16%) in 2018, 0.05% (95% CI: 0-0.15%) in 2019, respectively, presenting a downward trend from 2015 to 2019 with statistical significance (χ 2  = 11.64, P < 0.05)., Conclusions: The results suggest that S. japonicum infection still persisted in nature along the Yangtze River and traditional techniques might underestimate the prevalence of schistosomiasis in its intermediate hosts. Exploring and integrating molecular techniques into national surveillance programme could improve the sensitivity of surveillance system and provide guidance on taking actions against schistosomiasis., (© 2022. The Author(s).)

Background: We compared individuals' self-reported water contact from a questionnaire to direct observation of water contact. Questionnaires that accurately capture water contact are necessary to risk-stratify individuals and communities at high risk for schistosomiasis., Methods: Individuals (N=677) ages 7-30 y were included from three Schistosoma japonicum-endemic villages in Leyte, The Philippines. Each individual was observed for 12 d over the course of the 18-month study and the questionnaire was administered six times. A questionnaire index was derived that captured the number of self-reported contacts with water bodies for any purpose. An exposure index was created based on the sum of contacts that was weighted by the percentage of body surface area (BSA) exposed and exposure duration., Results: Of 16 water contact activities, only bathing and washing clothes exhibited a significant, positive correlation between self-reported contacts and the observed exposure index related to those contacts., Conclusions: We found that only the reported frequencies of bathing and washing clothes were significantly related to an individual's overall observed exposure index, while use of all reported contacts was not related to the observed exposure. This study further supports the need for questionnaires to be augmented by some measure of how much BSA is exposed and/or time is spent in the water on average for a specific activity., (© The Author(s) 2021. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)

Objective: To analyze the trends of human schistosomiasis prevalence in Hubei Province from 2004 to 2018, so as to provide the evidence for formulating the schistosomiasis elimination strategy in the province., Methods: All data pertaining to human schistosomiasis prevalence in Hubei Province were collected from 2004 to 2018, and the trends for changes in seroprevalence, egg-positive rate and prevalence of human Schistosoma japonicum infection were analyzed using a Joinpoint regression model., Results: Both of the numbers of residents seropositive and egg-positive for S. japonicum infections appeared a tendency towards a decline in Hubei Province from 2004 to 2018, and the prevalence of human S. japonicum infections reduced from 6.85% in 2004 to 0 in 2018. Joinpoint regression analysis showed that the prevalence of human S. japonicum infections appeared an overall tendency towards a reduction in Hubei Province from 2004 to 2018 [average annual percent change (AAPC) = -24.1%, P < 0.01], and the trends for the reduction were both significant during the period from 2004 to 2006 [annual percent change (APC) = -35.1%, P < 0.01] and from 2006 to 2018 (APC = -22.1%, P < 0.01). The prevalence of human S. japonicum infections appeared a tendency towards a decline in islet (AAPC = -25.1%, P < 0.01), inner embankment (AAPC = -26.4%, P < 0.01) and hilly subtypes of schistosomiasis-endemic areas (AAPC = -32.5%, P < 0.01) of Hubei Province from 2004 to 2018, and the prevalence all appeared a tendency towards a decline during the infection control stage (from 2004 to 2008), the transmission control stage (from 2009 to 2013) and the transmission interruption stage (from 2014 to 2018) (AAPC = -28.0%, -24.4% and -63.8%, all P values < 0.01). The seroprevalence of human S. japonicum infections appeared an overall tendency towards a decline in Hubei Province from 2004 to 2018 (AAPC = -14.5%, P < 0.01), and the trends for the reduction were both significant during the period from 2004 to 2012 (APC = -8.4%, P < 0.01) and from 2012 to 2018 (APC = -22.1%, P < 0.01). In addition, the egg-positive rate of human S. japonicum infections appeared an overall tendency towards a decline in Hubei Province from 2004 to 2018 (AAPC = -30.6%, P < 0.05), and the trend for the reduction was significant during the period from 2007 to 2014 (APC = -15.5%, P < 0.01)., Conclusions: The prevalence of human schistosomiasis appeared a tendency towards a decline in Hubei Province from 2004 to 2018, and the islet and inner embankment subtypes of endemic areas are a high priority for schistosomiasis control during the stage moving towards elimination in Hubei Province.

Objective: To analyze the dynamic changes of schistosomiasis in Poyang County of Jiangxi Province from 2004 to 2020, so as to provide insight into the development of the schistosomiasis elimination strategy., Methods: Schistosomiasis control data were captured from Poyang County from 2004 to 2020, and the epidemiological data of schistosomiasis were collected from national schistosomiasis surveillance sites in Poyang County from 2005 to 2020. The endemic status of schistosomiasis was analyzed in Poyang County from 2004 to 2020, and a Joinpoint regression analysis was performed to investigate the trends of schistosomiasis in Poyang County from 2004 to 2020., Results: The sero-prevalence and egg-prevalence of human Schistosoma japonicum infections reduced from 24.39% (24 976/102 397) and 4.53% (259/5 721) in 2004 to 5.37% (2 421/45 100) [annual percent change (APC) = average annual percent change (AAPC) = -8.64%] and 0 (0/3 963) in 2020 (APC = AAPC = -32.07%) in Poyang County, and the trends were both significant (both P < 0.01). The sero-prevalence of S. japonicum infections reduced from 1.21% (294/24 332) in bovines in 2013 to 0.58% (35/5 999) in 2020 in Poyang County, with one turning point (AAPC = -8.20%, P > 0.05). There were no townships or villages with emerging snail habitats in Poyang County from 2004 to 2020, and there were three turning points of trend in the proportion of snail areas detected in total snail areas (AAPC = -2.30%, P > 0.01). The sero-prevalence and adjusted prevalence of S. japonicum infections reduced from 60.82% (742/1 220) and 10.16% (124/1 220) in local residents in 2005 to 5.73% (70/1 221) and 0 in 2020 in national schistosomiasis surveillance sites of Poyang County, and the trends for sero-prevalence (APC = AAPC = 17.47%, P < 0.01) and adjusted prevalence of S. japonicum infections (APC = AAPC = -44.92%, P < 0.01) were both statistically significant. S. japonicum infections were identified in 10 (2005) and 2 local livestock (2007), with prevalence of 10.00% (10/100) and 13.33% (2/15), respectively, and S. japonicum infections were detected in snails in 2008 and 2009; however, no positive samples of mixed O. hupensis were detected by loop-mediated isothermal amplification., Conclusions: The endemic situation of schistosomiasis control had remarkably reduced in Poyang County from 2004 to 2020; however, there are still challenges for consolidating schistosomiasis control achievements and even elimination of schistosomiasis.

Schistosomiasis has been subjected to extensive control efforts in the People's Republic of China (China) which aims to eliminate the disease by 2030. We describe baseline results of a longitudinal cohort study undertaken in the Dongting and Poyang lakes areas of central China designed to determine the prevalence of Schistosoma japonicum in humans, animals (goats and bovines) and Oncomelania snails utilizing molecular diagnostics procedures. Data from the Chinese National Schistosomiasis Control Programme (CNSCP) were compared with the molecular results obtained.Sixteen villages from Hunan and Jiangxi provinces were surveyed; animals were only found in Hunan. The prevalence of schistosomiasis in humans was 1.8% in Jiangxi and 8.0% in Hunan determined by real-time polymerase chain reaction (PCR), while 18.3% of animals were positive by digital droplet PCR. The CNSCP data indicated that all villages harboured S. japonicum-infected individuals, detected serologically by indirect haemagglutination assay (IHA), but very few, if any, of these were subsequently positive by Kato-Katz (KK).Based on the outcome of the IHA and KK results, the CNSCP incorporates targeted human praziquantel chemotherapy but this approach can miss some infections as evidenced by the results reported here. Sensitive molecular diagnostics can play a key role in the elimination of schistosomiasis in China and inform control measures allowing for a more systematic approach to treatment.

Objective: To compare the effectiveness of loop-mediated isothermal amplification (LAMP) assay and microscopic examinations for detection of Schistosoma japonicum infections in Oncomelania hupensis in transmission-interrupted regions, so as to provide insights into the optimization of snail surveillance tools in these regions., Methods: Four hilly schistosomiasis-endemic villages where transmission interruption was achieved were selected in Heqing County of Yunnan Province as the study villages, including Xinzhuang and Gule villages in hilly regions and Lianyi and Yitou villages in dam regions. Snail survey was performed by means of systematic sampling combined with environmental sampling in July 2018. All captured snails were identified for S. japonicum infections using microscopy. In addition, 10 to 20 snails were randomly sampled from each snail habitat following microscopy, numbered according to environments and subjected to LAMP assay. The positive rate of settings with S. japonicum -infected snails was compared among villages., Results: A total of 7 949 living snails were captured from 83 snail habitats in 4 villages, and no S. japonicum infection was detected in snails. There were 226 mixed samples containing 1 786 snails subjected to LAMP assay, and positive LAMP assay was found in 3 mixed samples from 3 snail habitats in 2 dam villages. The positive rates of settings with S. japonicum -infected snails were comparable between Lianyi Village (one setting) and Yitou Village (2 set tings) (5.89% vs. 14.29%, P = 0.344). However, the overall positive rate of settings with S. japonicum -infected snails was significantly higher in dam villages (9.67%, 3/31) than in hilly villages (0) ( P = 0.048)., Conclusions: LAMP assay is more sensitive to detect S. japonicum infections in O. hupensis than conventional microcopy method, which may serve as a supplementary method for detection of S. japonicum infections in O. hupensis in high-risk snail habitats in hilly transmission-interrupted regions.

Objective: To evaluate the effectiveness of the integrated schistosomiasis control measures in Changzhou City from 2015 to 2020, so as to provide insights into the formulation of the strategy used to consolidate the schistosomiasis elimination achievements., Methods: The annual schistosomiasis control working report and integrated schistosomiasis control data were collected in Changzhou City from 2015 to 2020, and the prevalence of Schistosoma japonicum infections in humans and livestock and snail status were analyzed to evaluate the effectiveness of the integrated schistosomiasis control measures., Results: During the period from 2015 to 2020, a total of 112 061 person-time individuals received serological tests for S. japonicum infections in Changzhou City, and the sero-prevalence was 0.15% to 1.09% during the 6-year period, with a significant difference seen among years (χ 2 = 288.11, P < 0.05). From 2015 to 2020, a total of 13 435 person-time individuals received stool examinations, with no egg-positives identified; among 5 840 herd-time livestock receiving schistosomiasis examinations, no positives were detected, while a 100% coverage of fencing livestock was seen each year. During the 6-year period, a total of 38.40 hm 2 snail habitats were found, including 8.97 hm 2 emerging snail habitats, and among the 2 344 snails dissected, no S. japonicum infection was found. Chemical treatment covered an area of 385.71 hm 2 , and environmental improvements covered an area of 200.39 hm 2 . The mean density of living snails was less than 0.1 snails/0.1 m 2 in snail habitats found in Changzhou City each year from 2015 to 2020, and the coverage of harmless toilets was 100% in 2020. During the 6-year period, a total of 3.740 6 million person-time individuals were given schistosomiasis health education in Changzhou City., Conclusions: Changzhou City is now at the post-elimination surveillance stage; however, there are still factors affecting schistosomiasis transmission. The schistosomiasis surveillance system remains to be improved to consolidate the schistosomiasis elimination achievements in Changzhou City.

Objective: To analyze the surveillance data of schistosomiasis in Xiaogan City, Hubei Province from 2016 to 2020, so as to provide the scientific evidence for understanding the epidemiological changes of schistosomiasis and evaluating the schistosomiasis control strategy., Methods: A total of 16 surveillance sites were selected in the schistosomiasis endemic foci of Xiaogan City from 2016 to 2020, where Schistosoma japonicum infections in humans, livestock and Oncomelania snails and the schistosomiasis transmission risk were monitored. The schistosomiasis surveillance results were descriptively analyzed., Results: During the period from 2016 to 2020, there was no schistosomiasis emergency epidemic in Xiaogan City. A total of 660 sero-positive individuals were identified in Xiaogan City during the 5-year period, and the seroprevalence of S. japonicum infections reduced from 2.08% in 2016 to 0.97% in 2020. Higher seroprevalence of S. japonicum infections was detected in men than in women, and in individuals at ages of over 60 years than in those at other age groups; however, no egg-positives were detected in humans or livestock. The mean density of living snails was 0.05 to 0.06 snails/0.1 m 2 during the 5-year period, and the occurrence of frames with snails increased from 2.99% in 2016 to 3.92% in 2020; however, no S. japonicum infection was found in snails., Conclusions: The endemic situation of schistosomiasis remarkably decreases in Xiaogan City during the period from 2016 through 2020. Further improvements of the sensitive and effective schistosomiasis surveillance system are required with an emphasis on the monitoring of the schistosomiasis transmission risk and management of floating populations.

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2020, and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2020. A total of 450 counties (cites, districts) were found to be endemic for schistosomiasis in China, with 28 376 endemic villages covering 71 370 400 people at risk of infections. Among the 450 endemic counties (cities, districts), 74.89% (337/450), 21.87% (98/450) and 3.33% (15/450) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2020, 29 517 cases with advanced schistosomiasis were documented in China. In 2020, 11 117 655 individuals received inquiry examinations and 1 798 580 were positive; 5 263 082 individuals received serological tests and 83 179 were sero-positive. A total of 273 712 individuals received stool examinations and 3 were positive, including one case of acute schistosomiasis. In 2020, snail survey was performed in 19 733 endemic villages in China and Oncomelania snails were found in 7 309 villages, accounting for 37.04% of all surveyed villages, with 15 villages identified with emerging snail habitats. Snail survey covered an area of 736 984.13 hm 2 and 206 125.22 hm 2 snail habitats were found, including 1 174.67 hm 2 emerging snail habitats and 1.96 hm 2 habitats with infected snails. In 2020, 544 424 bovines were raised in the schistosomiasis-endemic areas of China, and 147 887 received serological examinations, with 326 positives detected, while 130 673 bovines received stool examinations, with no positives identified. In 2020, there were 19 214 patients with schistosomiasis receiving praziquantel chemotherapy, and 964 103 person-time individuals and 266 280 herd-time bovines were given expanded chemotherapy. In 2020, molluscicide treatment was performed in 136 141.92 hm 2 snail habitats, and the actual area of chemical treatment was 71 980.22 hm 2 , while environmental improvements were performed in snail habitats covering an area of 1 464.03 hm 2 . Data from the national schistosomiasis surveillance sites of China showed that the mean prevalence of Schistosoma japonicum infections were both zero in humans and bovines in 2020, and no S. japonicum infection was detected in snails. The results demonstrate that the overall endemic status of schistosomiasis remains at a low level in China and the goal of the National Thirteenth Five-Year Plan for Schistosomiasis Control was achieved as scheduled; however, the endemic situation of schistosomiasis rebounded in local areas. Precision schistosomiasis control and intensified monitoring of the endemic situation and transmission risk of schistosomiasis are required to be performed to facilitate the progress towards elimination of schistosomiasis steadily.

Background: Schistosomiasis japonica remains an important public health concern due to its potential to cause severe outcomes and long-term sequelae. An integrated control strategy implemented in the Peoples' Republic of China has been shown to be effective to control or interrupt the transmission of schistosomiasis. The objective of this study is to estimate the disease burden of schistosomiasis and assess the cost-effectiveness of the integrated control strategy focused on different major interventions at three stages for schistosomiasis control in a lake setting, to provide reference for policy making or planning., Methods: Annual cost data of schistosomiasis control during 2009-2019 were obtained from the control program implementers in Jiangling County, Hubei Province, China. Economic costs are provided in constant 2009 Chinese Yuan (CNY). Epidemiological data of schistosomiasis were collected from the Jiangling county station for schistosomiasis control. Disease burden of schistosomiasis was assessed by calculating years of life lost (YLLs) owing to premature death, years lived with disability (YLDs) and disability-adjusted life years (DALYs). DALYs were calculated as the sum of YLLs and YLDs. We then conducted a rudimentary cost-effectiveness analysis by determining the ratio by dividing the difference between the average cost of integrated control strategy at transmission control (2013-2016) or transmission interruption (2017-2019) and the average cost at stage of infection control (2009-2012) with the difference between the DALYs of schistosomiasis at different control stages. Descriptive statistics on the costs and DALYs were used in the analysis., Results: The total economic costs for schistosomiasis control in Jiangling County from 2009 to 2019 were approximately CNY 606.88 million. The average annual economic costs for schistosomiasis prevention and control at stages of infection control (2009-2012), transmission control (2013-2016), and transmission interruption (2017-2019) were approximately CNY 41.98 million, CNY 90.19 million and CNY 26.06 million respectively. The overall disease burden caused by schistosomiasis presented a downward trend. Meanwhile, the disease burden of advanced cases showed an upward trend with the DALY increased from 943.72 to 1031.59 person-years. Most disease burden occurred in the age group over 45 years old (especially the elderly over 60 years old). Taking the infection control stage as the control, the incremental cost-effectiveness ratio of integrated control strategy was CNY 8505.5 per case averted, CNY 60 131.6 per DALY decreased at transmission control stage and CNY -2217.6 per case averted, CNY -18 116.0 per DALY decreased at transmission interruption stage., Conclusions: The disease burden of schistosomiasis decreased significantly with the implementation of the integrated prevention and control strategy. Surveillance and management on elder population should be strengthened to decrease diseases burden. There remains a need for well-conducted studies that examine the long-term cost-effectiveness of the integrated control strategy for schistosomiasis. GRAPHIC ABSTARCT.

Objective: To investigate the changes in the endemic situation of schistosomiasis in national surveillance sites of Sichuan Province, so as to provide the scientific evidence for formulating the schistosomiasis elimination strategy., Methods: From 2015 to 2019, 63 national schistosomiasis surveillance sites were assigned in Sichuan Province, in which Schistosoma japonicum infections were monitored in humans, livestock, wild feces and snails. The monitoring data were descriptively analyzed., Results: A total of 94 119 person-time local residents were serologically screened for S. japonicum infections in 63 national surveillance sites of Sichuan Province from 2015 to 2019, with sero-prevalence rates ranging from 1.28% to 3.11%, and the sero-positives were predominantly detected in local residents at ages of over 50 years and in farmers. A total of 94 119 person-time mobile populations were serologically screened for S. japonicum infections in the national surveillance sites during the 5-year period, with sero-prevalence of 1.10% to 1.59%. There were no egg-positives identified in either local residents or mobile populations. Among the 6 126 herd-time livestock detected, no egg-positives were identified, and no S. japonicum infection was detected in the 205 wild feces. Snail survey was performed covering an area of 8 484.08 hm 2 , and 724.80 hm 2 snail habitats were identified, including 2.43 hm 2 emerging snail habitats and 63.00 hm 2 re-emerging snail habitats. The mean occurrence of frames with snails was 6.87% to 19.63%, and the mean density of living snails was 0.18 to 0.62 snails/0.1 m 2 in the national surveillance sites of Sichuan Province from 2015 to 2019; however, no S. japonicum infection was detected in snails., Conclusions: The endemic situation of schistosomiasis has reduced to the lowest level in Sichuan Province; however, there is a rise in snail habitats, and there is still a risk of schistosomiasis resurgence. Further improvements of the surveillance system for schistosomiasis are required to achieve the goal of schistosomiasis elimination in Sichuan Province as soon as possible.

According to monitoring data of Anhui, Jiangxi, Hubei, Jiangsu Provinces, in this paper the transmission of schistosomiasis is studied based on Barbour's mathematical model. The values of the basic reproduction number and key parameters are obtained with two methods. The first method is to calculate directly by using parameter values in references. The second one is to estimate parameter values by the methods of noise measurement and data smoothing and then to obtain new values of basic reproduction number. Comparing these two methods, we found the second method is good to fit the data. This parameter values can be used as reference values in other provinces. Finally, some numerical simulations are carried out to discuss the development trend of prevalence of humans and snails in each province. It is found that schistosomiasis in four provinces is expected to be eliminated with the improvement or maintenance of the standards of prevention and control. Furthermore, the time needed is different in the different four provinces.

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.

Background: While the dispersal of hosts and vectors-through active or passive movement-is known to facilitate the spread and re-emergence of certain infectious diseases, little is known about the movement ecology of Oncomelania spp., intermediate snail host of the parasite Schistosoma japonicum, and its consequences for the spread of schistosomiasis in East and Southeast Asia. In China, despite intense control programs aimed at preventing schistosomiasis transmission, there is evidence in recent years of re-emergence and persistence of infection in some areas, as well as an increase in the spatial extent of the snail host. A quantitative understanding of the dispersal characteristics of the intermediate host can provide new insights into the spatial dynamics of transmission, and can assist public health officials in limiting the geographic spread of infection., Methodology/principal Findings: Oncomelania hupensis robertsoni snails (n = 833) were sampled from 29 sites in Sichuan, China, genotyped, and analyzed using Bayesian assignment to estimate the rate of recent snail migration across sites. Landscape connectivity between each site pair was estimated using the geographic distance distributions derived from nine environmental models: Euclidean, topography, incline, wetness, land use, watershed, stream use, streams and channels, and stream velocity. Among sites, 14.4% to 32.8% of sampled snails were identified as recent migrants, with 20 sites comprising >20% migrants. Migration rates were generally low between sites, but at 8 sites, over 10% of the overall host population originated from one proximal site. Greater landscape connectivity was significantly associated with increased odds of migration, with the minimum path distance (as opposed to median or first quartile) emerging as the strongest predictor across all environmental models. Models accounting for land use explained the largest proportion of the variance in migration rates between sites. A greater number of irrigation channels leading into a site was associated with an increase in the site's propensity to both attract and retain snails., Conclusions/significance: Our findings have important implications for controlling the geographic spread of schistosomiasis in China, through improved understanding of the dispersal capacity of the parasite's intermediate host., Competing Interests: The authors have declared that no competing interests exist.

Schistosomiasis is a snail-borne disease caused by worms of the genus Schistosoma. Worldwide, human schistosomiasis remains a serious public health problem, threatening ∼800 million people in 78 countries with a loss of 70 million disability-adjusted life years. Schistosoma japonicum is the only human blood fluke that occurs in China. As one of the countries suffering greatly from schistosomiasis, over the past 65 years, China has made great strides in controlling schistosomiasis, blocking the transmission of S. japonicum in five provinces, remarkably reducing transmission intensities in the other seven endemic provinces, and China is currently preparing to move toward the elimination of this disease before 2025. However, while on the road to schistosomiasis elimination, emerging challenges merit attention, including severe advanced cases, increased movements of population and livestock, large-area distribution of intermediate host snails, limitations of new drug developments and no vaccine available, as well as imported schistosomiasis and its potential risk.

With the goal set to eliminate schistosomiasis nationwide by 2020, The People's Republic of China has initiated the surveillance-response stage to identify remaining sources of infection and potential pockets from where the disease could reemerge. Shifting the focus from classical monitoring and evaluation to rapid detection and immediate response, this approach requires modelling to bridge the surveillance and response components. We review here studies relevant to schistosomiasis modelling in a Chinese surveillance-response system with the expectation to achieve a practically useful understanding of the current situation and potential future study directions. We also present useful experience that could tentatively be applied in other endemic regions in the world. Modelling is discussed at length as it plays an essential role, both with regard to the intermediate snail host and in the definitive, mammal hosts. Research gaps with respect to snail infection, animal hosts and sectoral research cooperation are identified and examined against the prevailing background of ecosystem and socioeconomic changes with a focus on coexisting challenges and opportunities in a situation with increasing financial constraints., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To understand the current status of advanced schistosomiasis patients, deliver medical treatment, and improve the case management in Zhejiang Province., Methods: The cases previously diagnosed or suspected as advanced schistosomiasis in the province were the subjects of the investigation. Questionnairing (demographical information, disease history, etc.), clinical examination (ascites syndrome, abdominal palpation), laboratory examination (blood biochemistry, anti-Schistosoma japonicum antibody, eggs), and ultrasonography of the abdomen were used confirming the diagnosis. Treatment was given to the patients., Results: There were 1 060 advanced schistosomiasis patients in 32 counties of 7 prefectures in the province. Majority of them distributed in water network regions, and lived with poor economic conditions. The average age of the patients was (66.3 +/- 9.3), with 89.3% ranged from 50 to 80 years old. Clinically 71.3% of the cases were with splenomegaly, 27.6% with ascites, 0.9% cases of multiple granuloma in the colon and 0.2% cases with dwarfism. 1 023 patients (96.5%) had received medical treatments. 69.4% of the cases had serious complications with advanced schistosomiasis and 52.5% had concurrently disorders in other systems. 71.1% of the patients had subjective symptoms and 65.2% had hepatosplenomegaly with hepatic fibrosis and dysfunction. The serum positive rate of anti-S. japonicum antibody was 15.7%. Stool hatching test and microscopy revealed no eggs in fecal samples, but 24 out of 38 cases were found metamorphic eggs by rectal biopsy. Three years' medical treatment improved the clinical conditions in 74.3% of the cases., Conclusion: Situation of the advanced schistosomiasis patients is quite critical. Treatment and care are urgently needed especially for those aged 50 to 80 years old. [

The first two phases of a national prevalence survey of schistosomiasis in The Philippines were completed in Mindanao in 2005 and the Visayas in the first quarter of 2007. The design was a stratified two-step systematic cluster sampling, with two Kato-Katz thick smears examined from each participant. In Mindanao, a total of 22 provinces spread in six regions were covered by the survey with five barangays (equivalent to a village) per province for a total of 110 barangays. The response rate was 70.9% with a total of 21,390 individuals examined. The province of Maguindanao, a known endemic area for schistosomiasis japonica, failed to take part in the survey. In the Visayas, 10 out of 11 provinces, spread out in three regions, participated in the survey. There were 6321 respondents for an overall participation rate of 32.2%. Mindanao showed a wider coverage of the disease than the Visayas (60% versus 45%). By region, Caraga or Region 13 ranked first in Mindanao and Region 8 in the Visayas. By province, Agusan del Sur is first on the list, followed by Northern Samar and then Eastern Samar. Overall, the prevalence rate among males is higher than that of females suggesting the occupational hazard of farming and fishing among the males. The higher exposure among farmers and fishermen is also borne out by the age distribution of the disease. Prevalence remains consistently high among the adults compared with the younger age groups. The survey also covered other helminth infections that can be detected in a stool survey, notably soil-transmitted helminthes and food-borne trematodes.

After reviewing the schistosomiasis control program in China with focusing on the socio-economic impact on schistosomiasis endemicity, we introduce the promotion process of morbidity control strategy undertaken before and during the World Bank Loan Project (WBLP) on Schistosomiasis Control. We analyzed the data derived from case study of morbidity control for schistosomiasis, and evaluated the efficacy of chemotherapy. It is suggested that appropriate drug treatment declines worm burden and the intensity of infection as well as prevalence, but chemotherapy alone can hardly reduce the transmission because zoonotic Schistosoma japonicum infection has a great impact on the transmission of the disease. Therefore, the strategies in different (high, medium, and low) transmission areas during the maintenance stage were put forward in consideration of challenges in national control program in the future.

The literature of the past 4-5 yr on serodiagnosis and seroepidemiology of schistosomiasis is reviewed. A variety of assays with different antigens are being used for serodiagnosis. Several purified antigens appear to be sensitive and specific, but have little if any capability of indicating duration of infection, parasite burden, or effect of chemotherapy. The results of long-term posttherapy field studies indicate that serology has a role in monitoring control programs. Standardized serologic assays and the need for International Standard Reference Sera are emphasized. A standardized enzyme-linked immunosorbent assay based on the Falcon Assay Screening Test system (FAST-ELISA), and involving a standard reference serum pool, is suitable for both serodiagnosis and field studies. Measurement of circulating antigens as a parameter of active infection is considered to have increased potential, compared with antibody measurement, in management of clinical disease and in control programs. Recombinant DNA technology may be useful for producing standard antigens for use in assays measuring antibody or circulating antigen. Time-resolved immunofluorescence involving europium-labeled conjugates may provide the increased assay sensitivity needed for measurement of circulating antigen.

Schistosomiasis ranks among the major public health problems in the tropics and subtropics. The disease is caused by the parasite Schistosoma, a flatworm with a life cyclus including man as the definitive host and a freshwater snail as the intermediate host. During the last ten years one hundred cases of this disease have been reported in Norway. We report two cases of schistosomiasis, one patient infected with Schistosoma japonicum, the first reported case in Norway, the other with Schistosoma mansoni and Schistosoma haematobium. We discuss the disease, including the clinical picture and treatment.

A study tour in China provided information on the current status of schistosomiasis. Although many counties have been cleared of Oncomelania snails, problem areas still exist in the lakes region of the central Yangtze Valley, in hilly or mountainous terrain, and where water level cannot be controlled. In the central Yangtze area the main reservoir of infection is now considered to be cattle. It was estimated that the prevalence of schistosomiasis in 1983 was about 2.4 million cases, mostly light. Considerable effort is being made to develop immunodiagnostic methods to identify the relatively few and often subclinical cases that occur in sparsely endemic areas. Nationwide eradication does not seem feasible at present, necessitating continued surveillance to maintain and consolidate progress and prevent reintroduction of the parasite or its host snails in areas freed from the disease.