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The endemic situation of schistosomiasis and Oncomelania snail status in Yanjiang Village, Hanjiang District decreased significantly from 2005 to 2010. However, the surveillance in key population such as fishmen and boatmen still needs to be strengthened.

A survey of Oncomelania snail distribution was carried out with the systematic sampling method in combination with the environmental sampling method. A questionnaire survey was performed to find out the sites where stool examination-positive patients were infected. The results showed that there were 1 721 infected snail spots in Jingzhou City. Most of infected snail spots (94.1%) were only 500 m far away from the nearest residential areas from 2004 to 2010. About 97% of patients considered that the sites where they were infected with schistosome were only 400 meters far away from their residential areas. In conclusion, the survey with a questionnaire method in patients with positive stool examinations can quickly identify the environments with infected snails.

The analysis of endemic situation of schistosomiasis in Zongyang County from 2006 to 2010 showed that the infection rates of schistosomiasis remained at a lower level with a declined trend. There were only distributed acute schistosomiasis patients each year. However, the densities of Oncomelania snails and infected snails still maintained at a high level. Therefore, we should continually strengthen the prevention efforts, especially infectious source control.

Objective: To develop a spatio-temporal model of schistosomiasis japonica based on Bayesian model, and to analyze the spatio-temporal pattern of schistosomiasis, as well as to evaluate the impact of environment changes on schistosomiasis endemic., Methods: Different Bayesian models were established by employing the data of the periodical surveillance on schistosomiasis during 1996-2005 period by taking into account of the uncertainty in sensitivity and specificity of diagnostic test, then the best fitness model was selected to analyze the spatio-temporal pattern of schistosomiasis and evaluate the impact of environment changes on schistosomiasis., Results: The model with space-time interaction was a better fitting model. No significant temporal correlation was found in human infection rate of Schistosoma japonicum, and the difference of spatial structure between human infection rates of each year was significant. The prediction map of S. japonicum infection showed the changes of infection in the south areas of the Yuan River were not significant, while the prevalence increased significantly in the north areas of the river, which indicated that the impact of the implementation of project on partial abandon areas for water storing on prevalence of S. japonicum was stronger than that of the project on completed abandon areas for water storing., Conclusions: It is feasible to develop the spatio-temporal model of schistosomiasis japonica based on Bayesian model, and this inetegrated Bayesian model approach may become a powerful and statistically robust tool for estimating and evaluating the control strategy.

Schistosoma japonicum is endemic in the Philippines, China and Indonesia, and infects more than 40 mammalian host species, all of which can act as reservoirs of infection. In China, water buffaloes have been shown to be major reservoirs of human infection. However, in the Philippines, carabao have not been considered important reservoir hosts for S. japonicum due to the low prevalence and infection intensities reported, the only exception being a qPCR-based study indicating 51% of carabao were S. japonicum-positive. However, the low prevalence found for the same animals when using conventional copro-parasitological techniques means that there is still confusion about the role of carabao in the transmission of schistosomiasis japonicum. To address this inconsistency, and to shed light on the potential role of carabao in the transmission of S. japonicum in the Philippines, we undertook a pilot survey, collecting fecal samples from animals in Western Samar Province and we used a combination of molecular and copro-parasitological techniques to determine the prevalence and intensity of S. japonicum. We found a high prevalence of S. japonicum in the carabao using a validated real-time PCR (qPCR) and a copro-parasitological tool, the formalin-ethyl acetate sedimentation (FEA-SD) technique. A much lower prevalence of S. japonicum was recorded for the same fecal samples using conventional PCR, the Kato-Katz technique and miracidial hatching. These results suggest that, due to their low diagnostic sensitivity, traditional copro-parasitological techniques underestimate infection in carabao. The use of FEA-SD and qPCR provides a more accurate diagnosis. Based on these findings, the role of bovines in the transmission of S. japonicum appears to be more important in the Philippines than previously recognized, and this may have significant implications for the future control of schistosomiasis there, particularly as, in contrast with previous surveys, we found an unprecedented high prevalence of S. japonicum in humans.

Objective: To assess the diagnostic efficacy of the currently most widely used indirect hemagglutination assay (IHA) and enzyme-linked immunosorbent assay (ELISA) for detection of Schistosoma japonicum human infections., Methods: A comprehensive search was undertaken from China National Knowledge Infrastructure, Wanfang Database, VIP Database, PubMed, Cochrane Library, Science Citation Index Expanded, Proquest, and the inclusion and exclusion criteria were strictly settled. The funnel plot was used to assess the publication bias, Cochran's Q test was employed to measure the homogeneity between studies, a summary receiver operating characteristic (SROC) curve was used to compare the diagnostic accuracy between the IHA and ELISA qualitatively by means of the Weighted Least Square method, the Ordinary Least Square method and the Robust regression method, and the diagnostic odds ratio (DOR) was drawn to compare the accuracy quantitatively., Results: Out of 785 publications, 19 papers were eventually selected for analysis. Literature quality assessment indicated that minor publication bias existed in studies pertaining IHA test, but no bias was found in literatures regarding ELISA test. The heterogeneity test showed a heterogeneity between studies was present (χ(2)=466.07 and 34.67, both P values<0.0001). The areas under the SROC curves of IHA were all higher than that of ELISA test using the three methods (Weighted Least Square method: 0.766 vs. 0.695, Ordinary Least Square method: 0.826 vs. 0.741, Robust regression: 0.815 vs. 0.715). The TPR* values for IHA and ELISA were 0.710, 0.759, 0.749, and 0.650, 0.686 and 0.666, respectively, and OR values were 5.997, 9.937, 8.893, and 3.432, 4.784 and 3.959, respectively. The DOR of IHA was 9.41 (95% CI: 4.88-18.18), and 4.78 (95% CI: 3.21-7.13) for ELISA., Conclusions: All above results revealed that the diagnostic performance of IHA is better than that of ELISA. However, taking into account their unsatisfactory diagnostic value in areas with low infection intensity, a search for a better diagnostic test that can be applied in field situations in China should be given high priority., (Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

Background: Schistosomiasis japonica is prevalent in Asian countries and it remains a major public health problem in China. The major endemic foci are the marsh and lake regions of southern China, particularly the Dongting Lake region bordering Hunan and Hubei provinces, and the Poyang Lake region in Jiangxi province. Domestic ruminants, especially bovines, have long been considered to play a major role in the transmission of Schistosoma japonicum to humans., Methods and Findings: A miracidial hatching technique was used to investigate the prevalence of S. japonicum infections in domestic ruminants and field feces collected from two towns located to the south and east of Dongting Lake, Hunan province, between 2005 and 2010. The overall prevalence of infection was not significantly reduced from 4.93% in 2005 to 3.64% in 2008, after which it was maintained at this level. Bovines comprised 23.5-58.2% of the total infected ruminants, while goats comprised 41.8-76.5%. Infection rates in cattle and goats were significantly higher than those found in buffalo in most study years. The prevalence in buffalo younger than three years was significantly higher than that in those aged over three years. All the positive field samples of feces were derived from bovines in Nandashan. In Matang Town, 61.22% of the positive field feces were from bovines, while the rest were from goats. The positive rates for field feces were approximately the same in April and November/October., Conclusions: The present study found that bovines and goats are major sources of S. japonicum infection in the Dongting lake region and there was age-related resistance in buffalo. Both bovines and goats should be treated equally when controlling S. japonicum infections in the Dongting lake region. It is essential to conduct an additional mass treatment in late March or early April, in addition to the original treatment scheme.

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

The surveillance of schistosomiasis in a national schistosomiasis surveillance site, Caohui Village, Yangxin County, 2005 - 2010 showed that the infection rates of residents and livestock decreased from 4.56% and 28.33% to 1.19% and 1.67%, respectively. However, the endemic situation was still of instability. Therefore, we should strengthen the comprehensive control measures including the control of infectious sources in the light of local conditions to control the schistosomiasis endemic situation.

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

Objective: To study the risk factors of schistosomiasis related to household economic condition and individual behavior in marshland and lake regions, so as to provide evidences for schistosomiasis control., Methods: Six villages were sampled with the stratified cluster sampling method, 2 339 villagers from 1 247 households were surveyed by a questionnaire and meanwhile their sera were assayed for schistosomiasis by IHA. The Logistic regression was used to analyze the relationship between the results of serological examinations and risk factors., Results: The Logistic regression model fitted well (R2 = 0.598 4) and it indicated that there existed a regressive relationship between the antibody positive rate and the endemic situation of village, family economic status, age, education level and infection history of schistosomiasis., Conclusion: Suitable measures should be made in according to the local economic situation, endemic type and population to control the transmission of schistosomiasis effectively.

Objective: To understand the dynamic changes of the potential prevalent factors of schistosomiasis in Chaohu Lake area so as to provide forecast information on the outbreak of schistosomiasis in the area., Methods: From 2008 to 2010, fixed and mobile surveillance sites in potential endemic areas of Juchao District in Chaohu City, which was located in the southeast side of Chaohu Lake, were selected, and the schistosomiasis infection situation of local people, mobile population and livestock were investigated by immunological assays and/or stool examinations. The distribution of Oncomelania snails was surveyed in risk areas and suspicious areas, the spreading patterns of Oncomelania snails were observed in rivers that directly connected with the Yangtze River, and the Oncomelania snails were raised in the cages on the beaches of Chaohu Lake and a control area, and their survival and reproduction capacity was observed., Results: In 2008, a total of 301 local people were screened by IHA, and there were no positives. From 2008 to 2010, a total of 321, 362 and 306 mobile population were examined by IHA, respectively, and the positive rate of antibody were 3.74%, 4.97% and 2.94%, respectively. The antibody positives were tested by stool examinations, and the positive rates were 66.67%, 50% and 55.56%, respectively. A total of 91 local livestock and 92 livestock from endemic areas were examined respectively by the miracidium hatching method, and there were no positives. A total of 97.8 hm2 risk areas and 193.62 hm2 suspicious areas in the potential endemic area were surveyed respectively, but no Oncomelania snails were found. The investigation results on snail spreading patterns indicated that snails could spread into Chaohu Lake by adsorbing on floating debris. The field study revealed that Oncomelania snails could survive and reproduce in the Lake., Conclusions: The imported infectious sources of schistosomiasis have been found in Chaohu Lake area, and the higher possibility of imported Oncomelania snails spreading into the Lake and surviving and reproducing in the lake is predicted. Therefore, effective measures should be taken to decrease the risks of schistosomiasis transmission in the potential endemic area.

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

After "5.12" earthquake, 5 128 reconstruction people from schistosomiasis endemic areas were surveyed for schistosome infection from 2009 to 2001. There were 261 seropositive persons with the positive rate of 5.09%, but there were no persons with positive stool examination. The seropositive rate was higher in reconstruction persons from schistosomiasis endemic areas than that in local residents, therefore, we still should strengthen the active schistosomiasis surveillance of reconstruction people from schistosomiasis endemic areas in order to prevent input of infection source so as to consolidate the achievements of schistosomiasis control.

The surveillance of schistosomiasis in Sanzhou Village, a national schistosomiasis surveillance site, in Gaoqiao Town of Dantu District, Zhenjiang City from 2005 to 2009 showed that the schistosomiasis morbidity remained in a low level in the surveillance site; however, the Oncomelania snails and infected snail areas remained high. It is suggested that, in addition to snail control, comprehensive control measures should be strengthened, and the causes of infected snails in marshland should be investigated, so as to clarify the roles of various hosts in transmission of schistosomiasis.

Objective: To understand the rates of underestimation of Schistosoma japonicum infection by Kato-Katz technique with different stool samples and different smears in field site., Methods: With 27 Kato-Katz thick smears (3 stool samples with 9 thick smears each) for 3 consecutive years as a "gold standard", the rates of underestimation of schistosome infection by Kato-Katz technique with different stool samples and different smears were evaluated in a schistosomiasis endemic village., Results: The examined rates of schistosome infection increased and the rates of underestimation decreased gradually with the increase of the number of Kato-Katz thick smears examined. The rates of underestimation of 3 smears were 40.98%-50.80% and the rates of underestimation of 6 smears were 25.48%-32.39%. The rates of schistosome infection based on the reading of 27 Kato-Katz thick smears were 10.96% in 2008, 8.54% in 2009 and 3.73% in 2010 respectively, but the rates of underestimation of various Kato-Katz thick smears were similar. There were no significant differences among the readings of 3, 6, and 9 smears of 1 stool sample, 3, 6 and 9 smears of 3 stool samples, 6 smears of 2 stool samples, 6 smears of 1 stool sample, and 6 smears of 3 stool samples., Conclusions: In a community with low-intensity of schistosome infection, the rate of underestimation is big by Kato-Katz technique with the reading of 3 smears of 1 stool sample. It suggested that it is better to increase smears rather than the number of stool samples examined.

This annual report overviewed the national endemic status of schistosomiasis japonica in People's Republic of China in 2010. By the end of 2010, a total of 325 824 cases of schistosomiasis japonica were estimated with a decrease rate of 10.92% compared to those in 2009. A total of 43 acute cases were reported, decreased by 44.16% compared to those in 2009. A total of 25 115 advanced cases were treated in 2010, increased by 3.43% compared to that in 2009. About 373 596.18 hm2 of areas infested with Oncomelania snail were found in 2010, and about 1 081.80 hm2 newly detected areas were reported. A total of 1 476 606 cattle were raised in schistosomiasis transmission regions in 2010. The infection rate of cattle infected with Schistosoma japonicum was 1.04% in 2010, with a little increase comparing to that in 2009 (1.03%).

Background: Schistosomiasis is a severe public health problem in China. It has been predicted that the ecological changes caused by the "Three Gorges Dam", the world's largest hydropower project, could potentially aggravate the spread of schistosomiasis in the area. This study focused on investigating (a) local residents' knowledge on the potential risks of schistosomiasis and (b) the capability of local health personnel in preventing schistosomiasis., Materials and Methods: A quantitative survey combined with qualitative interviews was conducted in three counties of the reservoir area during November and December 2008. A total of 1386 inhabitants and 180 local health personals participated in questionnaire survey; 18 inhabitants, 21 health professionals, and 8 local government officials were interviewed., Results: Of the surveyed inhabitants, 66.3% had no access to safe drinking water; 47.9% had water-contact regularly through farming or swimming; 58.7% did not have hygienic toilets; and only 13.7% used methane for energy. Besides, only 3.8% of the inhabitants had knowledge scores higher than 6 points within the range 0-10. Educational level, occupation and income were significant predictors of knowledge score (P<0.05). Only about 5% of the inhabitants had some knowledge on schistosomiasis. Among health professionals surveyed, 6.7% had college or higher education; 26.7% had prior schistosomiasis control experience; 75.6% did not receive any relevant training in the past year; and only 52.2% had basic knowledge of schistosomiasis. The logistic regression analysis identified occupation and time at work as significant factors to their knowledge level (P<0.05). Moreover, the surveillance work was often severely hindered by a shortage of funding, and challenged by monitoring of migrant population. There were very limited training opportunities for the health workers, and almost no health education for inhabitants, if any, neither efficient nor effective., Conclusion: Although there were multiple risks for potential Schistosoma japonicum infections in the study area, the knowledge level on schistosomiasis and surveillance was relatively low both in local residents and health personnel. Thus, more health education and professional training are urgently required to local residents and health personnel, respectively. By considering limited activities in surveillance and health education been implemented, a strategy plan on intervention to ensure a stronger inter-sectoral cooperation is recommended in order to reduce schistosomiasis transmission risks in this area., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Appropriate diagnostics to monitor disease trends and assess the effectiveness and impact of interventions are essential for guiding treatment strategies at different thresholds of schistosomiasis transmission and for certifying elimination. Field validation of these assays is urgently needed before they can be adopted to support policy decisions of the national programme for control and elimination of schistosomiasis in P.R. China. We compared the efficacy and utility of different immunoassays in guiding control strategies and monitoring the endemic status of S. japonicum infections towards elimination., Methodology/principal Findings: A cross-sectional survey was conducted in seven villages with different transmission intensities settings to assess the performance and utility of three immunoassays, e.g., an indirect hemagglutination assay (IHA&#95;JX), an enzyme linked immunosorbent assay (ELISA&#95;SZ), and a dot immunogold filtration assay (DIGFA&#95;SH). 6,248 individuals aged 6-65 years old who gave consent and supplied their stool and blood samples were included for data analysis. Results showed that ELISA&#95;SZ performed significantly higher sensitivity (95.45%, 95%CI: 92.94-97.97%) than IHA&#95;JX (87.59%, 95%CI: 83.51-91.49%) and DIGFA&#95;SH (79.55%, 95%CI: 74.68-84.41%), especially in subgroups with very low infection intensity. The specificity of ELISA&#95;SZ, IHA&#95;JX, DIGFA&#95;SH in 6-9 year olds with occasional exposure was nearly 90%. DIGFA&#95;SH performed the highest screening efficacy for patients among three assays with overall positive predicative value of 13.07% (95%CI: 11.42-14.72%). We found a positive correlation of antibody positive rate of IHA&#95;JX with results of stool examination in age strata (r = 0.70, P<0.001). Seropositivity of IHA&#95;JX in children aged 6-9 years old showed an excellent correlation with prevalence of schistosome infection in the seven communities (r = 0.77, P<0.05)., Conclusions/significance: Studies suggest that ELISA&#95;SZ could be used to guide selective chemotherapy in moderate or low endemic regions. IHA&#95;JX could be used to as a surveillance tool and for certifying elimination of schistosomiasis through monitoring children as a sentinel population.

Background: Due to the success of the national schistosomiasis control programme in China, transmission has been sufficiently reduced in many areas to severely limit identification of areas at risk by conventional snail surveys only. In this study, we imported Google Earth technology and a Global Positioning System (GPS) into the monitoring system for schistosomiasis surveillance of the banks of the Yangtze River in Jiangsu Province, China., Methods: A total of 45 sites were selected and the risk was assessed monthly by water exposure of sentinel mice at these sites from May to September in 2009 and 2010. The results were assembled and broadcast via the Google Earth platform., Results: The intensity of schistosomiasis transmission showed peaks of risk in June and September of 2009, while there was only one small peak in June in 2010 as the number of detected positive transmission sites dropped dramatically that year thanks to improved mollusciciding. River ports were found to be areas of particular risk, but ferry terminals and other centres of river-related activities were also problematic., Conclusions: The results confirm that the surveillance system can be rapidly updated and easily maintained, which proves the Google Earth approach to be a user-friendly, inexpensive warning system for schistosomiasis risk.

Worldwide schistosomiasis continues to be a serious public health problem. Over the past five decades, China has made remarkable progress in reducing Schistosoma japonicum infections in humans to a relatively low level. Endemic regions are currently circumscribed in certain core areas where re-infection and repeated chemotherapy are frequent. At present, selective chemotherapy with praziquantel is one of the main strategies in China's National Schistosomiasis Control Program, and thus diagnosis of infected individuals is a key step for such control. In this paper we review the current status of our knowledge about diagnostic tools for schistosomiasis japonica. A simple, affordable, sensitive, and specific assay for field diagnosis of schistosomiasis japonica is not yet available, and this poses great barriers towards full control of schistosomiasis. Hence, a search for a diagnostic approach, which delivers these characteristics, is essential and should be given high priority.

Schistosomiasis is a major infectious disease and a public health concern in many areas in China and other countries. Sensitive method for detection of the parasite is critical for early diagnosis and for monitoring of effective treatment of the disease. In this study, we developed a highly sensitive TaqMan real-time PCR assay for the detection of Schistosoma japonicum DNA in mouse feces and serum samples. This assay was based on the DNA sequence of the S. japonicum 18S rRNA gene and was able to detect 10 fg of S. japonicum genomic DNA, which is 100 times more sensitive than conventional PCR. We were able to detect the S. japonicum DNA one week post-infection in mouse sera and 4 weeks post-infection in feces, which was one week earlier than egg detection by microscopy in feces. This assay was also highly specific for Asian Schistosomes which are causative species of human Schistosomiasis. In single sex male cercariae infected mice, parasite DNA was only detected in the first 4 weeks post-infection, suggesting that the DNA was derived from decaying worms' corpse in the first 4 weeks whereas the DNA was mainly from decaying parasite eggs afterwards. Therefore we conclude that the established TaqMan real-time PCR assay is a sensitive, specific and convenient method that could be used for the early diagnostic evaluation of S. japonicum infection in humans and for monitoring outbreaks in endemic areas with low prevalence., (Copyright © 2011 Elsevier B.V. All rights reserved.)

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

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

Objective: To evaluate the simulation effect of Schistosoma japonicum Cellular Automata (SjCA) model by using the multi-dimensional evaluation system., Methods: Several selected indicators, including the Youden index, sensitivity, specificity, accuracy rate and prevalence distance were applied to assess the validity of the SjCA model. The effectiveness of each indicator for model evaluation was compared., Results: Different indicators in the multi-dimensional evaluation system generated assorted combination of optimized parameters for the SjCA model. The best model according to prevalence distance (99.97%) did not guarantee the ultimate fit when using accuracy rate (79.70%) as the evaluation indicator., Conclusions: The multi-dimensional evaluation system is helpful for accurately assessing the simulation results of the discrete stochastic models such as SjCA, and is promising to be universalized to evaluate other similar epidemic dynamics models.

Objective: To measure and evaluate the health inequalities due to chronic schistosomiasis japonica., Methods: Based on years lived with disability (YLD) caused by chronic schistosomiasis, a concentration index and Gini index, along with a concentration curve and Lorenz curve, the health inequalities between sexes, age groups or endemicities were identified and quantified., Results: The age concentration index was 0.395 of females and 0.380 of males, with no significant difference between them. More than 60% of YLD was contributed by those aged > or = 45 years old who accounted for about a third of total population in both sexes. Gini index was 0.666 of Dangtu County and 0.451 of Hanshou County, and 60% of YLD was contributed by the highly endemic villages., Conclusions: The concentration index and Gini index could quantify the magnitude of health inequalities well. The priority of morbidity control should be given to those aged > or = 45 years old and living in highly endemic villages.

Schistosomiasis is a kind of common disease around the riverside or lakeside areas, especially popular in rural areas, and causes huge economic loss. Based on existing schistosomiasis dynamic models and data, a new method of working out coefficients, and an improved model were provided in our study. The improved model can be applied to the study of the characteristics of transmission of schistosomiasis, and the effect of new control methods for schistosomiasis was evaluated.

Objective: To develop an aetiology detection method with higher sensitivity and accuracy for schistosomiasis japonica., Methods: The fresh fecal samples were collected from residents of a schistosomiasis japonica endemic village in Laozi County of Hubei Province. Two samples per person were collected in two consecutive days. Each sample was examined three times with Kato-Katz technique, then the negative cases were re-examined by the stool hatching test after the egg concentration with nylon-tissue bags. The detective rates and the relation with egg per gram (EPG) of different methods were analyzed and compared. The epidemiology data were collected as well., Results: A total of 562 residents were examined by Kato-Katz technique, and 67 of them were positive. The samples of 495 negative persons were re-examined by using the hatching test after the egg concentration with nylon-tissue bags. Six persons were positive. The total number of positive cases was 73. The rates of Kato-Katz technique with three slides of one sample and six slides of two samples were 65.8% and 91.8%, respectively. The detective rate was increased with the increase of examining slides. The geometrical averages of EPG from one slide to six slides were 61.12, 31.92, 23.71, 20.88, 19.35 and 8.83, respectively. The accuracy of EPG increased with the increase of numbers of slides., Conclusion: Kato-Katz technique with six slides of two samples is applicable in diagnosis of schistosomiasis japonica in order to achieve higher detective rate and more accurate EPG.

Over the past years there has been an increasing trend in the application of mathematical models in the studies and control of infectious disease. With development of computing technologies and increasing access to them, it becomes appealing for public health professionals to use mathematical models in their work. In this paper based on our previous experience working on environmental determinants and control of schistosomiasis in the hilly and mountainous regions of Sichuan Province, we introduce principles and basic procedures in building a mathematical model for schistosomiasis transmission; we then illustrate the use of a mathematical model to integrate data from diverse sources and to aid in designing control strategies, assessing progress, and evaluating surveillance programs.

Objective: To discuss the evaluation index of the disease burden of chronic schistosomiasis and its calculation methods., Methods: The epidemiological data came from the thematic research carried out in two schistosome-endemic counties in lake areas between 2004 and 2005. The specific prevalence rates by age group, gender and endemic type were calculated. According to the age-specific disability weight obtained in the thematic research, the years lived with disability (YLDs) and the rates of YLD of stratified samples by age and gender, and the total YLDs of the two counties were calculated., Results: The total YLDs were 1 056.26 and 3 967.43 person-years in Dangtu and Hanshou counties, respectively. The contributing rate of Grade I type village to the total YLDs of two counties was 37.95% (40.08% in Dangtu and 37.39% in Hanshou). For different stratums by age and gender, the older ones and male tended to have larger YLDs. Compared to the non-endemic areas, chronic schistosomiasis brought an average extra of 4.398 and 1.505 years per 1 000 person to population in Dangtu and Hanshou counties, respectively., Conclusion: The evaluation to YLDs of chronic schistosomiasis is helpful for prioritizing intervention areas and population, as well as providing a new index for the evaluation of effectiveness of control measures.

The accurate characterization of Schistosoma japonicum has important implications for analyzing genetic variation and would provide basic data for disease control. Previous studies using proteins, coding sequences, and especially antigen-coding genes showed lower genetic variation among S. japonicum isolates from mainland China. Therefore, the present study focused on variations in intron sequences of housekeeping and antigen-coding genes, which may be more informative for genetic analysis. We compared sequence variation between introns of two housekeeping genes and two antigen-coding genes. All 4 genes were polymorphic among all the S. japonicum isolates in mainland China, with 103, 158, 47, and 19 polymorphic (segregating) sites per kilobase in intron sequences of Actin, FBPA, 22.6kDa antigen and GST-26, respectively. Introns of housekeeping genes were slightly more polymorphic than coding and non-coding regions of antigen-coding genes examined in the present study within or among lake/marshland and mountainous types. Phylogenetic analysis based on sequences of single gene or combined sequences of multiple genes showed no specific clustering comprising parasites from single geographical or endemic regions. These results demonstrated that introns of housekeeping and antigen-coding genes were polymorphic, but the intron sequences examined in the present study were not suitable markers for examining genetic relationship among different isolates from endemic regions in mainland China., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

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

The effect of habitat fragmentation on schistosome-transmitting snails was assessed in an intervention village and a control village in Sichuan Province, China. Snail habitats were fragmented by environmental management. After 2 years, the proportions of quadrats with snails in the fragmented habitats decreased from 9.35% to 2.41% in one patch (c3) and from 12.20% to 6.57% in another patch (c12), whilst the proportions in habitats without fragmentation did not alter significantly. Mean snail density decreased from 0.246 to 0.063 snails/0.11 m2 in patch c3 and from 0.356 to 0.177 snails/0.11 m2 in patch c12, whilst the mean snail density of other patches did not alter significantly. Most snails from the same patch and/or its remaining patches after fragmentation clustered together in the phylogenetic tree, except for c1, c3 and its remaining patches (c5, c6 and c11). Snail habitats in the study zone exhibited visible fragmentation. Habitat fragmentation could decrease the snail population size and limit migration and dispersal of snails between patches., (Copyright © 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.)

Background: Schistosoma japonicum is a major public health concern in the Peoples' Republic of China (PRC), with over one million people infected and another 50 million living in areas at risk of infection. Based on ecological, environmental, population genetic and molecular factors, schistosomiasis transmission in PRC can be categorised into four discrete ecosystems or transmission modes. It is predicted that the Three Gorges Dam (TGD) will impact upon the transmission of schistosomiasis in the PRC, with varying degree across the four transmission modes. We undertook longitudinal surveillance from 2002 to 2006 in sentinel villages both above and below the TGD across five provinces (Hunan, Jiangxi, Hubei, Anhui and Sichuan) to determine whether there was any impact of the TGD on schistosomiasis transmission during its construction. Here we present the results from a schistosomiasis-endemic village located above the dam in Sichuan Province., Results: Baseline results showed a human S. japonicum prevalence of 42.0% (95% CI: 36.6-47.5). At follow-up, results showed that the incidence of S. japonicum infection in the selected human cohort in Shian decreased by three quarters from 46% in 2003 to 11.3% in 2006. A significant (P < 0.01) downward trend was also evident in the yearly adjusted (for water contact) odds ratios. Over the four years of follow-up, the incidence of S. japonicum infection in bovines declined from 11.8% in the first year to zero in the final year of follow-up., Conclusions: The substantial decrease in human (75%) and bovine (100%) incidence observed in Shian village can probably be attributed to the annual human and bovine PZQ treatment of positives; as seen in drug (PZQ) intervention studies in other parts of PRC. If an increase in schistosome transmission had occurred as a result of the TGD, it would be of negligible size compared to the treatment induced decline seen here. It appears therefore that the construction of the TGD had virtually no impact on schistosomiasis transmission in Shian village over the period of study. Furthermore, contrary to previous reports from Sichuan downplaying the role of animals in human schistosome transmission, bovines may indeed play a role.

Objective: To investigate the effect of suspension concentrate of niclosamide (SCN) on killing cercariae of Schistosoma japonicum on water surface, optimization and impact on fish, so as to establish an emergency-treatment intervention for rapidly killing cercariae and eliminating water infectivity., Methods: SCN was formulated into different concentrations of solutions, and then the solutions were sprayed on the surface of water containing S. japonicum cercariae. The water infectivity was determined by using mice at 0, 10, 30 min after spraying SCN. SCN was formulated into a solution of 100 mg/L and then sprayed on the surface of the water by using the spraying values of 0.01, 0.02, 0.03 g/m2 and 0.04 g/m2. At 30 min and 60 min after spraying, the water infectivity was determined by using mice. Zebra fish were transferred into the static water, then 100 mg/L SCN (s), using spraying values of 0.01, 0.02, 0.03 g/m2 and 0.04 g/m2, were sprayed on water surface. At 0, 10, 30, 60 min after spraying, the samples were collected at water depths of 0, 10, 20, 30, 40 cm, and niclosamide was determined by using high-performance liquid chromatography. The death of zebra fish was continually observed within 96 h after spraying SCN., Results: At 0, 10, 30 min after spraying 1 000, 100, 10, 1, 0.1 mg/L SCN on water surface, the infectivity of water significantly decreased. At 30 min after spraying 1 000 mg/L and 100 mg/L SCN, no schistosome infectivity was detected in the water. At 30 min after spraying 100 mg/L SCN, with spraying values of 0.01, 0.02, 0.03, 0.04 g/m2, the water infectivity significantly reduced, and no infectivity was found 60 min after spraying SCN. After the surface of static water was sprayed with 100 mg/L SCN, the peak concentration was found at 0 min, and the solution diffused to site with a water depth of 10 cm after 10 min, and 30 min later, SCN diffused to the whole water body, and distributed evenly. After spraying 100 mg/L SCN on the surface of water with a volume of (3.14 x 20(2) x 50) cm3, by using the spraying value of 0.02 g/m2, 96 h later, no death of zebra fish was found., Conclusions: From 30 to 60 min after spraying 100 mg/L SCN, with the value of 0.02 g/m2, on the surface of S. japonicum-infested water, the water infectivity can be eliminated, and there is no evident toxicity to fish. This cercaria-killing method, as an emergency-treatment intervention for infested water, can be applied in those surveillance and forecast sites.

Three schistosomiasis patients pathologically diagnosed were detected in Luxi City, Yunnan Province, a non-endemic area of schistosomiasis. All the cases were hospitalized for serious intestinal diseases, and Schistosoma japonicum eggs were detected under their colonic mucosa. The 3 patients all denied they had contacted with infested water outside their resident place, and it was suggested that they might be infected in the local area.

Praziquantel is widely used for the treatment of human schistosomiasis. However, in recent years, there has been increasing concern about the resistance of Schistosoma species to praziquantel. The study described here was designed to evaluate the current susceptibility to praziquantel in S. japonicum in China. During the non-transmission period of schistosomiasis, a random sample of 4760 subjects from the main endemic foci of China were examined using parasitological stool examination. In total, 584 subjects were identified as being infected with S. japonicum, with a prevalence rate of 12.27%. Among them, 565 stool-egg-positive subjects were treated with praziquantel in a single oral dose of 40 mg/kg. Six weeks post-treatment, among the 505 villagers re-examined, 480 (95.05%) had no detectable S. japonicum eggs. Twenty-one subjects still excreting eggs after the first treatment were treated with praziquantel for the second time. All stool samples, including those from those participants with second treatment were re-examined 6 weeks after the second treatment, and no stool-egg-positives were found. The results indicate that the current efficacy of praziquantel against S. japonicum is still high and has not changed after more than 2 decades of repeated, expanded chemotherapy in the main endemic areas of China. It is suggested that no evidence of tolerance or resistance to praziquantel in S. japonicum was detected in China.

The sustained transmission and spread of environmentally mediated infectious diseases is governed in part by the dispersal of parasites, disease vectors and intermediate hosts between sites of transmission. Functional geospatial models can be used to quantify and predict the degree to which environmental features facilitate or limit connectivity between target populations, yet typical models are limited in their geographical and analytical approach, providing simplistic, global measures of connectivity and lacking methods to assess the epidemiological implications of fine-scale heterogeneous landscapes. Here, functional spatial models are applied to problems of surveillance and control of the parasitic blood fluke Schistosoma japonicum and its intermediate snail host Oncomelania haupensis in western China. We advance functional connectivity methods by providing an analytical framework to (i) identify nodes of transmission where the degree of connectedness to other villages, and thus the potential for disease spread, is higher than is estimated using Euclidean distance alone and (ii) (re)organize transmission sites into disease surveillance units based on second-order relationships among nodes using non-Euclidean distance measures, termed effective geographical distance (EGD). Functional environmental models are parametrized using ecological information on the target organisms, and pair-wise distributions of inter-node EGD are estimated. A Monte Carlo rank product analysis is presented to identify nearby nodes under alternative distance models. Nodes are then iteratively embedded into EGD space and clustered using a k-means algorithm to group villages into ecologically meaningful surveillance groups. A consensus clustering approach is taken to derive the most stable cluster structure. The results indicate that novel relationships between nodes are revealed when non-Euclidean, ecologically determined distance measures are used to quantify connectivity in heterogeneous landscapes. These connections are not evident when analysing nodes in Euclidean space, and thus surveillance and control activities planned using Euclidean distance measures may be suboptimal. The methods developed here provide a quantitative framework for assessing the effectiveness of ecologically grounded surveillance systems and of control and prevention strategies for environmentally mediated diseases.

One small previous study found that praziquantel reduced hookworm infection. In this study, 607 subjects were enrolled in a longitudinal study. At enrollment and every 3 months for 18 months, three stool samples were collected, and the intensity of infection with Schistosoma japonicum and soil-transmitted helminths (STHs) was quantified. All subjects were treated with 60 mg/kg praziquantel at baseline. Three months post-treatment, the percent of subjects who were hookworm-infected decreased to 46.5% from 61% at baseline. The putative cure rate was 23.7%. The 95% confidence interval around the change in hookworm egg counts from baseline to 6 and 12 months post-treatment was negative and did not include zero. The percent reduction in hookworm egg counts from baseline to 3 months post-treatment was 40.8%. Praziquantel treatment did not decrease the infection intensity of STHs. Control programs using praziquantel may have the added benefit of reducing hookworm infection and anemia in areas of coendemnicity.

The present study studied the genetic variation among Schistosoma japonicum isolates from different endemic regions in mainland China and examined the phylogenetic relationships of zoonotic trematodes using the combined mitochondrial 16S and 12S ribosomal DNA sequences. The fragments of 16S and 12S rDNA were amplified from 22 S. japonicum isolates, and sequenced, and the relevant sequences of other nine trematode species belonging to six genera in four families were downloaded from GenBank, and their phylogenetic relationships were re-constructed by unweighted pair-group method with arithmetic averages analyses using the combined 16S and 12S rDNA sequences, with Trichinella spiralis as outgroup. The results showed that the partial sequences of mitochondrial 16S and 12S rDNA of S. japonicum were 757 and 797 bp, respectively, and they were quite conserved among the S. japonicum isolates. Phylogenetic analysis revealed that the combined 16S and 12S rDNA sequences were not able to distinguish S. japonicum isolates in mountainous areas from those in lake/marshland areas in mainland China. However, the combined sequences could distinguish different species of zoonotic trematodes. Therefore, the combined mitochondrial 16S and 12S rDNA sequences provide an effective molecular marker for the inter-species phylogenetic analysis and differential identification of zoonotic trematodes.

Hubei Province, along with four other provinces in the central and eastern China where schistosomiasis is endemic (Anhui, Hunan, Jiangsu, and Jiangxi), is located in the lake and marshland regions along the Yangtze River. High population density, large numbers of farm cattle, and huge areas of snail habitat are the main characteristics that maintain the persistence of the disease and the transmission of the parasite Schistosoma japonicum in these regions. Based on the schistosomiasis infection data from Hubei province, we propose a mathematical model for the human-cattle-snail transmission of schistosomiasis. The model is a system consisting of six ordinary differential equations that describe susceptible and infected human, cattle and snail subpopulations. After analyzing the existence of the disease-free equilibrium of the model, we determine the basic reproduction number and use the model to simulate the schistosomiasis infection data from Hubei Province. By carrying out sensitivity analyses of the basic reproduction number on various parameters, we find that the transmission of S. japonicum between cattle and snails plays a more important role than that between humans and snails in the endemicity of schistosomiasis in these regions. This strongly suggests that, to control and eventually eradicate schistosomiasis in the lake and marshland regions in China, a more comprehensive approach needs to include environmental factors in order to break the cattle-snail transmission cycle., (2010 Elsevier B.V. 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 epidemiology of schistosomiasis japonicum over small areas remains poorly understood, and this is particularly true in China. We aimed to identify high-risk areas for schistosomiasis and associated risk factors in the Poyang Lake region, China. A cross-sectional study was conducted and 60 of 920 persons (6.5%) were found to be infected with Schistosoma japonicum. Locations of households and snail habitats were determined using a hand-held global positioning system. We mapped the data in a geographical information system and used spatial scan statistics to explore clustering of infection, logistic regression and Bayesian geostatistical models to identify risk factors for each individual's infection status and multinomial logistic regression to identify risk factors for living in a cluster area. The risk of schistosomiasis was spatially clustered and higher in fishermen and males, not in persons who lived in close proximity to snail habitats and infected water sources. This study has demonstrated significant spatial variation in the prevalence of schistosomiasis at a small spatial scale. The results suggest that demographic factors (gender, occupation) rather than the distance to infected water are driving human transmission at small-scale spatial levels. Such information can be used to plan locally targeted interventions based on anthelminthic drug administration, snail control and sanitation improvement.

Background: As the transmission of many other parasitic diseases, the transmission of schistosomiasis is a complex process governed by natural, socio-economic factors and human life style. Based on the life cycle of Schistosoma japonicum, some models have been developed. However, the human-environment interaction, especially through agricultural activities, has not been explicitly modeled in previous efforts., Objective: To understand the effect of agricultural land use and other social economic factors on schistosomiasis transmission by explicitly including agricultural land use, human water contact behaviors, feces processing, and control strategies in a multi-level agent based model., Methods: We proposed a spatially explicit agent-based schistosomiasis transmission model and describe its design and implementation. We chose one endemic village near Xichang, China to construct a virtual environment with the "patch". We modeled the behaviors (water contact, feces contamination and disease control) of various agents (villages, households and individuals) in the environment and predicted the potential infection risk of human and snails in space and time with consideration of socio-economic and human behavioral factors., Results: We obtained simulation results based on different scenarios of schistosomiasis control involving two dominant types of land use and four types of control measures. We also compared the effect of different timing on chemotherapy treatment., Conclusions: The scheme for multi-level agent simulation including human-environment interaction behaviors in schistosomiasis transmission is a useful framework for assessment of different control strategies., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The potential impact of the Three Gorges Dam (TGD) on schistosomiasis transmission in China has invoked considerable global concern. The TGD will result in changes in the water level and silt deposition downstream, favoring the reproduction of Oncomelania snails. Combined with blockages of the Yangtze River's tributaries, these changes will increase the schistosomiasis transmission season within the marshlands along the middle and lower reaches of the Yangtze River. The changing schistosome transmission dynamics necessitate a comprehensive strategy to control schistosomiasis. This review discusses aspects of the epidemiology and transmission of Schistosoma japonicum in China and considers the pathology, clinical outcomes, diagnosis, treatment, immunobiology, and genetics of schistosomiasis japonica together with an overview of current progress in vaccine development, all of which will have an impact on future control efforts. The use of synchronous praziquantel (PZQ) chemotherapy for humans and domestic animals is only temporarily effective, as schistosome reinfection occurs rapidly. Drug delivery requires a substantial infrastructure to regularly cover all parts of an area of endemicity. This makes chemotherapy expensive and, as compliance is often low, a less than satisfactory control option. There is increasing disquiet about the possibility that PZQ-resistant schistosomes will develop. Consequently, as mathematical modeling predicts, vaccine strategies represent an essential component in the future control of schistosomiasis in China. With the inclusion of focal mollusciciding, improvements in sanitation, and health education into the control scenario, China's target of reducing the level of schistosome infection to less than 1% by 2015 may be achievable.

Difficulty in controlling human Schistosoma japonicum infection is partly attributed to the presence of non-human definitive hosts. Water buffaloes are a major reservoir for transmission of S. japonicum to humans in China. However, in the Philippines, reports based on microscopic examination of buffalo stool identified a low prevalence of S. japonicum, and mathematical models using these data concluded that water buffaloes are not a major reservoir for transmission of S. japonicum to humans. We collected stool from 81 buffaloes in Macanip, Leyte, the Philippines, and assayed for S. japonicum infection by the Danish Bilharziasis Laboratory technique, the Kato-Katz technique, miracidia hatching, and a highly validated real-time polymerase chain reaction. The prevalence defined by each assay was 3.7%, 3.7%, 0%, and 51.5% respectively. Our results demonstrate that microscopic-based techniques dramatically underestimate the prevalence of S. japonicum infection in water buffaloes in the Philippines and warrant reexamination of the role of bovines in transmission of S. japonicum to humans in the Philippines.

Schistosoma japonicum remains highly endemic in many counties in China and has recently re-emerged, to a large extent, in previously controlled areas. To test the hypothesis that small rodents and less agriculturally important domestic animals such as dogs and cats may play an important role in the transmission and potential re-emergence of this disease, an annual investigation of S. japonicum among humans, domestic animals and rodents, combined with detailed surveys of the snail intermediate host, was performed across 3 marshland villages and 3 hilly villages in Anhui province of China over 2 consecutive years. The highest infection prevalence and intensity observed across all mammals was in rodents in the hilly region; while in the marshland, bovines were suspected as the main reservoirs. However, relatively high infection prevalence levels were also found in dogs and cats in both regions. Such results may have implications for the current human- and bovine-oriented control policy for this medically and veterinarily important disease, particularly within the hilly regions of mainland China.

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