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Xiaonong Zhou - One of the best experts on this subject based on the ideXlab platform.
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epidemiological features and effectiveness of schistosomiasis control programme in lake and Marshland region in the people s republic of china
Advances in Parasitology, 2016Co-Authors: S Q Zhang, Xiaonong Zhou, M Wang, T P WangAbstract:Abstract Schistosomiasis is one of neglected tropical diseases in the world. The People's Republic of China has made great achievements in schistosomiasis control through integrated interventions. Although the morbidity and mortality have been reduced to the lowest level in all three endemic regions, namely lake and Marshland regions, hilly and mountainous regions and plains with waterway networks regions, the endemic status in lake and Marshland region is still that of implementing the interventions in the higher endemicity areas towards elimination of schistosomiasis transmission. This review explores and analyses the endemic characteristics, control measures and its effectiveness in the course of schistosomiasis control programme, in order to provide more theoretical information and experiences for development of appropriate strategies leading to schistosomiasis elimination in the next stage in the country.
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schistosomiasis control effect of measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on Marshlands in Marshland and lake regions
Chinese journal of schistosomiasis control, 2014Co-Authors: Pengcheng Yang, Zhao Chen, Yiyi Li, Jing Xu, Shizhu Li, Xiaonong ZhouAbstract:OBJECTIVE: To evaluate the schistosomiasis control effect of the measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on Marshlands in Marshland and lake regions. METHODS: The retrospective review and field survey were implemented in the Jiangling and Gongan counties of Hubei Province where were implemented with the measure of replacing cattle with machine for cultivation, and Yuanjiang and Huarong counties of Hunan Province where were implemented with the measure of forbidding the depasturage of livestock on Marshlands. The schistosome infection status of human, cattle, and Oncomelania hupensis snails, and schistosome-infested field excreta were surveyed from 2007 to 2013. The effects of the interventions were compared before and after their implementations. RESULTS: The 6 villages of Hubei Province were implemented with the measure of replacing cattle with machine for cultivation, and 7 villages of Hunan Province were implemented with the measure of forbidding the depasturage of livestock on Marshlands. From 2007 to 2013, the schistosome infection rates of residents declined from 3.95% to 0.70% (χ2 = 128.376, P 0.05). The infection rate of cattle decreased from 3.66% in 2007 to 0.65% in 2013, and the descend range was 82.24% (χ2 = 13.692, P < 0.05). The field excreta was surveyed in the snail breeding place in 2013. The investigated area was 157.435 hm2, and 625 samples of field feces of cattle were collected with the density of field excreta of 3.97/hm2, and the positive rate was 1.12% (7/625). The schistosome infection rate of snails and the density of infected snails decreased successively from 2007, and no infected snails were detected from 2011 to 2013. CONCLUSIONS: The schistosomiasis endemic situation are decreased significantly after the interventions of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on Marshlands. Therefore, schistosomiasis control effect of these measures is notable in the Marshland and lake regions.
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current endemic situation and control strategy of schistosomiasis in lake and Marshland regions in china
Chinese journal of schistosomiasis control, 2011Co-Authors: Hongchen Chen, Xiaojun Zeng, Tianping Wang, Yousheng Liang, Xibao Huang, Yuesheng Li, Xiaonong ZhouAbstract:: This paper reviewed the current endemic features and situation of schistosomiasis in lake and Marshland regions in China, and discussed the comprehensive control strategy for schistosomiasis with emphasis on infectious sources control, including its theoretical basis, the reality conditions of implementation and technical composition, and also introduced the effectiveness of the pilot trails and their large-scale application as well as several issues in the implementation. The aim of the review is to accelerate the process of schistosomiasis control in lake and Marshland regions and promote the achievement of mid- and long-term goals in national schistosomiasis control program.
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remote sensing and spatial statistical analysis to predict the distribution of oncomelania hupensis in the Marshlands of china
Acta Tropica, 2005Co-Authors: Zhi-ying Zhang, Xiaonong Zhou, De-zhong Xu, Yun ZhouAbstract:Remote sensing and spatial statistical analysis were employed to predict the distribution of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum, in the Marshlands of Jiangning county in China. Surrogate indices related to environmental factors in the Marshlands were derived from a Landsat 7 ETM+ image, and the relationship between environmental covariates and the density of O. hupensis was analyzed by stepwise regression models and ordinary kriging. Although stepwise regression demonstrated that O. hupensis densities of live snails in the Marshlands related significantly to the modified soil-adjusted vegetation index, wetness and land surface temperature, the correlation coefficient was low (0.282). Therefore, spatial patterns of the regression residual were investigated by the semi-variogram method, and the spatial variation of O. hupensis density attributed to the spatial autocorrelation was estimated by ordinary kriging. The regression model of the snail density and ordinary kriging of its spatial variation were then combined with the aim of improving the prediction of O. hupensis. Following this approach, the prediction indeed improved considerably (0.852). Our results show that it is possible to predict the distribution of O. hupensis in these Marshlands by using remotely sensed environmental indices, and that spatial statistical analyses are capable of improving prediction accuracy. These findings are of relevance for mapping and prediction of schistosomiasis japonica in China, and hence the national control programme.
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Prediction of the spatial distribution of Oncomelania snails in Marshland of Jiangning County using the Ordinary Kriging
Chinese Journal of Parasitology and Parasitic Diseases, 2004Co-Authors: Zhi-ying Zhang, Xiaonong Zhou, De-zhong Xu, Hua Peng, Yun Zhou, Bo Zhang, Zi-li GongAbstract:OBJECTIVE: To explore the methods to predict the distribution of Oncomelania hupensis in the Marshland of Jiangning County. METHODS: Semi-variogram was used to analyze the spatial autocorrelation of snails' distribution in the Marshland of Jiangning using the Arcview8.1. A prediction map for the snails' distribution was established using the Ordinary Kriging and evaluated using the cross-validation. RESULTS: Analysis showed that the distribution of alive snails in the Marshland of Jiangning in the year 2000 was auto-correlated in spatial. The semi-variogram model which was spherical demonstrated that the variation of alive snails in spatial were related with distance apart when the distance was less than 0.0301. The prediction map of the snail distribution in the Marshland of Jiangning was established based on the semi-variogram using the Ordinary Kriging. The cross-validation showed that the prediction map could estimate the distribution of snails in the Marshland of Jiangning correctly. And the determinant coefficient for the prediction model was 0.973. CONCLUSION: It is feasible to predict the snail distribution in the Marshland of Jiangning County by using Ordinary Kringing and data from the surveillance spot.
Dabing Lu - One of the best experts on this subject based on the ideXlab platform.
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compatibility of schistosoma japonicum from the hilly region and oncomelania hupensis hupensis from the Marshland region within anhui china
Parasitology Research, 2014Co-Authors: Chenzhong Wang, Dabing Lu, Ying Li, Chaorong Bian, Jing SuAbstract:Schistosome japonicum remains one main public concern in China. This is exemplified in the hilly region in Anhui Province, where rodents have served as reservoirs for the parasite and no effective intervention could target such wild animals. The closer relationship between the hilly region and the near Marshland induces the worry of spread of the hill parasite to the Marshland region. Therefore, the level of snail-parasite compatibility between the hill parasite and snail populations from the Yangtze River valley was investigated. The results of this study demonstrated that both the hill (Shitai, Anhui) and the Marshland (Wuxi, Jiangsu) strains of parasite were more infective to the Marshland strains of snail (Zongyang and Hexian, Anhui) than to the hill strain of snail (Shitai, Anhui). When snails were individually exposed to one single miracidium, the longest prepatent period for cercarial development was observed in the combination of Shitai schistosome/Shitai snail. A nocturnal cercarial emergence pattern was observed for the hill parasite, either harbored in the hill or the Marshland strain of snails. The results suggested a high compatibility between the Marshland strains of snail and both the hill and the Marshland strains of parasite. This would have practical implications. Moreover, the fact of the lower compatible relationship between the hill parasite and its local intermediate hosts warranted more studies.
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identifying host species driving transmission of schistosomiasis japonica a multihost parasite system in china
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Dabing Lu, James W Rudge, Tianping Wang, Guoren Fang, Joanne P Webster, Mariagloria BasanezAbstract:Understanding disease transmission dynamics in multihost parasite systems is a research priority for control and potential elimination of many infectious diseases. In China, despite decades of multifaceted control efforts against schistosomiasis, the indirectly transmitted helminth Schistosoma japonicum remains endemic, partly because of the presence of zoonotic reservoirs. We used mathematical modeling and conceptual frameworks of multihost transmission ecology to assess the relative importance of various definitive host species for S. japonicum transmission in contrasting hilly and Marshland areas of China. We examine whether directing control interventions against zoonotic reservoirs could further reduce incidence of infection in humans or even eliminate transmission. Results suggest that, under current control programs, infections in humans result from spillover of transmission among zoonotic reservoirs. Estimates of the basic reproduction number within each species suggest that bovines (water buffalo and cattle) maintained transmission in the Marshland area and that the recent removal of bovines from this area could achieve local elimination of transmission. However, the sole use of antifecundity S. japonicum vaccines for bovines, at least at current efficacies, may not achieve elimination in areas of comparable endemicity where removal of bovines is not a feasible option. The results also suggest that rodents drive transmission in the hilly area. Therefore, although targeting bovines could further reduce and potentially interrupt transmission in Marshland regions of China, elimination of S. japonicum could prove more challenging in areas where rodents might maintain transmission. In conclusion, we show how mathematical modeling can give important insights into multihost transmission of indirectly transmitted pathogens.
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transmission of schistosoma japonicum in Marshland and hilly regions of china parasite population genetic and sibship structure
PLOS Neglected Tropical Diseases, 2010Co-Authors: Dabing Lu, James W Rudge, Tianping Wang, Christl A Donnelly, Guoren Fang, Joanne P WebsterAbstract:The transmission dynamics of Schistosoma japonicum remain poorly understood, as over forty species of mammals are suspected of serving as reservoir hosts. However, knowledge of the population genetic structure and of the full-sibship structuring of parasites at two larval stages will be useful in defining and tracking the transmission pattern between intermediate and definitive hosts. S. japonicum larvae were therefore collected in three Marshland and three hilly villages in Anhui Province of China across three time points: April and September-October 2006, and April 2007, and then genotyped with six microsatellite markers. Results from the population genetic and sibling relationship analyses of the parasites across two larval stages demonstrated that, within the Marshland, parasites from cattle showed higher genetic diversity than from other species; whereas within the hilly region, parasites from dogs and humans displayed higher genetic diversity than those from rodents. Both the extent of gene flow and the estimated proportion of full-sib relationships of parasites between two larval stages indicated that the cercariae identified within intermediate hosts in the Marshlands mostly came from cattle, whereas in the hilly areas, they were varied between villages, coming primarily from rodents, dogs or humans. Such results suggest a different transmission process within the hilly region from within the Marshlands. Moreover, this is the first time that the sibling relationship analysis was applied to the transmission dynamics for S. japonicum.
Hilmar Von Eynatten - One of the best experts on this subject based on the ideXlab platform.
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measuring sediment deposition and accretion on anthropogenic Marshland part i methodical evaluation and development
Estuarine Coastal and Shelf Science, 2014Co-Authors: Malte Schindler, Volker Karius, Matthias Deicke, Hilmar Von EynattenAbstract:Abstract The North Frisian Halligen (Northern Germany) are inhabited and highly anthropogenic modified coastal Marshlands. Today a lack of knowledge about sedimentological parameters prevent for a predicated discussion on their adaptation capacity to recent and future sea-level changes. A combined field and laboratory method to calculate Marshland accretion rates based on short-term (2010–2013) measurements of sediment depositions was developed. All studies were carried out at the Marshlands of the Halligen Hooge, Langeness and Nordstrandischmoor. One litre LDPE bottles and small synthetic turf mats were used as simple but coast, time and quantity efficient sediment trap devices. Up to a deposition rate, of ≈ 2.0 kg/m2, both devices gained comparable results. Above this threshold the retention efficiency of the turf mats is decreasing compared to the LDPD bottles. The combined use of bottles and mats, especially when deposition rates are not exceeding the threshold, allows to (1) checking internal consistency of the data, (2) detecting outliers with respect to cattle- or man-made damage, and (3) estimating possible effects of post-storm sediment remobilization. To transfer sediment depositions into rates of vertical accretion, the bulk dry density as well as the organic matter concentration of the correspondent marsh soil was considered using data from shallow percussion cores. These parameters are different among all Halligen. Higher inundation frequencies cause lower soil organic matter concentrations, resulting in higher bulk dry densities (BDD) of the soil (Hooge 0.64 g/cm3, Langeness 0.67 g/cm3, Nordstrandischmoor 0.83 g/cm3). Autochthonous organic material (by source of the Marshland vegetation) contributes by 9.0 ± 1.4 % (Hooge) to 21.4 ± 6.6 % (Nordstrandischmoor) to Marshland accretion, for a correspondent time scale of 1915–2011. Average accretion rates (2010–2013) were calculated with 1.2 ± 0.8 mm/a for Langeness, 1.5 ± 0.9 mm/a for Hooge and 2.6 ± 0.9 mm/a for Nordstrandischmoor.
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measuring sediment deposition and accretion on anthropogenic Marshland part ii the adaptation capacity of the north frisian halligen to sea level rise
Estuarine Coastal and Shelf Science, 2014Co-Authors: Malte Schindler, Volker Karius, Matthias Deicke, Arne Arns, Hilmar Von EynattenAbstract:Abstract Low coastlands, Marshlands and islands all over the world are challenged by rising water levels due to climatic changes. The adaptation capacity of such lowlands is based on frequent inundations and according sedimentation processes. Exemplarily, a system of small islands west of Northern Germany was investigated over three years. At three out of ten so-called Halligen located in the Wadden Sea, the adaptation capacity of the anthropogenic Marshland was determined. The Halligen Hooge, Langeness and Nordstrandischmoor have surface elevations only a few decimetres above mean high water and have to cope with an inundation frequency of nowadays up to 22 times per year. By use of methods introduced in Schindler et al. (2014, this volume) in combination with a 137 Cs and 210 Pb dating campaign on 12 sediment cores, vertical accretion rates were measured and detailed sediment accretion patterns presented. A good agreement was found between the used methods to calculate long term and short term Marshland accretion rates. Sediment deposition and vertical Marshland accretion is mainly controlled by the high tide events (single storm surges). Coastal protection structures, established in the early 20th century, decrease the inundation frequency and hinder the efficiency of the sediment transport by the tidal channel system on the Halligen. Vertical Marshland accretion based on 210 Pb dating for the time span 1915–2011 (1.0 ± 0.3 mm/a, Hooge, 1.2 ± 0.3 mm/a, Langeness and 2.6 ± 0.9 mm/a, Nordstrandischmoor) is in disequilibrium with the fast increasing mean high water level (MHW, 5.0 ± 0.3 mm/a). Projections until 2100 revealed that the extreme values (highest high waters, HHW) tend to rise much faster than the MHW or relative mean sea level (RMSL). Therefore an increasing hazard potential for the Halligen has to be expected if vertical Marshland accretion does not accelerate in the future.
James W Rudge - One of the best experts on this subject based on the ideXlab platform.
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identifying host species driving transmission of schistosomiasis japonica a multihost parasite system in china
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Dabing Lu, James W Rudge, Tianping Wang, Guoren Fang, Joanne P Webster, Mariagloria BasanezAbstract:Understanding disease transmission dynamics in multihost parasite systems is a research priority for control and potential elimination of many infectious diseases. In China, despite decades of multifaceted control efforts against schistosomiasis, the indirectly transmitted helminth Schistosoma japonicum remains endemic, partly because of the presence of zoonotic reservoirs. We used mathematical modeling and conceptual frameworks of multihost transmission ecology to assess the relative importance of various definitive host species for S. japonicum transmission in contrasting hilly and Marshland areas of China. We examine whether directing control interventions against zoonotic reservoirs could further reduce incidence of infection in humans or even eliminate transmission. Results suggest that, under current control programs, infections in humans result from spillover of transmission among zoonotic reservoirs. Estimates of the basic reproduction number within each species suggest that bovines (water buffalo and cattle) maintained transmission in the Marshland area and that the recent removal of bovines from this area could achieve local elimination of transmission. However, the sole use of antifecundity S. japonicum vaccines for bovines, at least at current efficacies, may not achieve elimination in areas of comparable endemicity where removal of bovines is not a feasible option. The results also suggest that rodents drive transmission in the hilly area. Therefore, although targeting bovines could further reduce and potentially interrupt transmission in Marshland regions of China, elimination of S. japonicum could prove more challenging in areas where rodents might maintain transmission. In conclusion, we show how mathematical modeling can give important insights into multihost transmission of indirectly transmitted pathogens.
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transmission of schistosoma japonicum in Marshland and hilly regions of china parasite population genetic and sibship structure
PLOS Neglected Tropical Diseases, 2010Co-Authors: Dabing Lu, James W Rudge, Tianping Wang, Christl A Donnelly, Guoren Fang, Joanne P WebsterAbstract:The transmission dynamics of Schistosoma japonicum remain poorly understood, as over forty species of mammals are suspected of serving as reservoir hosts. However, knowledge of the population genetic structure and of the full-sibship structuring of parasites at two larval stages will be useful in defining and tracking the transmission pattern between intermediate and definitive hosts. S. japonicum larvae were therefore collected in three Marshland and three hilly villages in Anhui Province of China across three time points: April and September-October 2006, and April 2007, and then genotyped with six microsatellite markers. Results from the population genetic and sibling relationship analyses of the parasites across two larval stages demonstrated that, within the Marshland, parasites from cattle showed higher genetic diversity than from other species; whereas within the hilly region, parasites from dogs and humans displayed higher genetic diversity than those from rodents. Both the extent of gene flow and the estimated proportion of full-sib relationships of parasites between two larval stages indicated that the cercariae identified within intermediate hosts in the Marshlands mostly came from cattle, whereas in the hilly areas, they were varied between villages, coming primarily from rodents, dogs or humans. Such results suggest a different transmission process within the hilly region from within the Marshlands. Moreover, this is the first time that the sibling relationship analysis was applied to the transmission dynamics for S. japonicum.
Yanyan Chen - One of the best experts on this subject based on the ideXlab platform.
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new integrated strategy emphasizing infection source control to curb schistosomiasis japonica in a Marshland area of hubei province china findings from an eight year longitudinal survey
PLOS ONE, 2014Co-Authors: Yanyan Chen, Xibao Huang, Zhengming Su, Rong Zhong, Xiaoping MiaoAbstract:Background Schistosomiasis remains a major public health problem in China. The major endemic foci are the lake and Marshland regions of southern China, particularly the regions along the middle and lower reach of the Yangtze River in four provinces (Hubei, Hunan, Jiangxi, and Anhui). The purpose of our study is to assess the effect of a new integrated strategy emphasizing infection source control to curb schistosomiasis in Marshland regions. Methods In a longitudinal study, we implemented an integrated control strategy emphasizing infection source control in 16 villages from 2005 through 2012 in Marshland regions of Hubei province. The interventions included removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water, building lavatories and latrines, praziquantel chemotherapy, controlling snails, and environmental modification. Results Following the integrated control strategy designed to reduce the role of bovines and humans as sources of Schistosoma japonicum infection, the prevalence of human S. japonicum infection declined from 1.7% in 2005 to 0.4% in 2012 (P<0.001). Reductions were also observed in both sexes, across all age groups, and among high risk occupations. Moreover, the prevalence of bovine S. japonicum infection decreased from 11.7% in 2005 to 0.6% in 2012 (P<0.001). In addition, all the 16 villages achieved the national criteria of infection control in 2008. Conclusion Our findings indicate that the integrated strategy was likely effective in controlling the transmission of S. japonicum in Marshland regions in China.
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assessing the effect of an integrated control strategy for schistosomiasis japonica emphasizing bovines in a Marshland area of hubei province china a cluster randomized trial
PLOS Neglected Tropical Diseases, 2013Co-Authors: Yanyan Chen, Yuesheng Li, Xicheng Hong, Xingjian Xu, Xi Chen, Chuanhua Yu, Yi Yuan, Rendong Li, Ping YiAbstract:Introduction More than 80% of schistosomiasis patients in China live in the lake and Marshland regions. The purpose of our study is to assess the effect of a comprehensive strategy to control transmission of Schistosoma japonicum in Marshland regions. Methodology/Principal Findings In a cluster randomized controlled trial, we implemented an integrated control strategy in twelve villages from 2009 through 2011 in Gong'an County, Hubei Province. The routine interventions included praziquantel chemotherapy and controlling snails, and were implemented in all villages. New interventions, mainly consisting of building fences to limit the grazing area for bovines, building safe pastures for grazing, improving the residents' health conditions and facilities, were only implemented in six intervention villages. Results showed that the rate of S. japonicum infection in humans, bovines, snails, cow dung and mice in the intervention group decreased from 3.41% in 2008 to 0.81% in 2011, 3.3% to none, 11 of 6,219 to none, 3.9% to none and 31.7% to 1.7%, respectively (P 0.05 for all comparisons). Moreover, a generalized linear model showed that there was a higher infection risk in humans in the control group than in the intervention group (OR = 1.250, P = 0.001) and an overall significant downward trend in infection risk during the study period. Conclusions/Significance The integrated control strategy, designed to reduce the role of bovines and humans as sources of S. japonicum infection, was highly effective in controlling the transmission of S. japonicum in Marshland regions in China. Trial Registration Chinese Clinical Trial Registry ChiCTR-PRC-12002405.