Drivers of autochthonous malaria cases over time: could the Central European present the African future?

BACKGROUND: Results of spatial and temporal comparison of malaria hotspots and coldspots could improve the health measures of malaria control and eradication strategies. The study aimed to reveal the spatially and temporally independent correlations between the potentially most effective background variables and the number of autochthonous malaria cases. METHODS: Relationships between malaria cases and background variables were studied in 2 km × 2 km sized quadrates (10 Central European and 10 African). In addition to the current habitat structure of the African sites, annual precipitation, and annual mean temperature, data of the above parameters detected in the nineteenth and twentieth centuries and currently in the Central European sites were included in the analyses (n = 40). Mann-Whitney tests, Principal Component Analysis, and Generalized Linear Models were used for the examinations. RESULTS: In addition to the apparent significant positive correlation of malaria cases with annual rainfall and mean temperature, several correlations were found for habitat parameters. The cover of marshlands in the 19th-century habitat structure of Central European quadrates was considerably the same as in the recent African ones. The extent of rural residential areas was significantly smaller in the 19th-century habitat structure of Central European quadrats than in present-day African ones. According to the revealed correlations, the surface cover of rural residential areas is the main driver of the number of autochthonous malaria cases that we can directly impact. CONCLUSIONS: The study confirmed with historical comparison that not only the annual rainfall and mean temperature, the cover of marshlands and other habitats with breeding sites, but also the elements of the rural human environment play a significant role in the high number of autochthonous malaria cases, probably through the concentration and enhancing sites for vector mosquitoes. The latter confirms that a rapid urbanization process could reduce malaria cases in the most infected areas of Africa. Until the latter happens, extensive biological control of Anopheles larvae and chemical control (both outdoor and indoor) of their imagoes, further mosquito nets, repellents, and carbon dioxide traps will need to be applied more widely in the most heavily infested areas.

Optimal prey for red fox cubs-An example of dual optimizing foraging strategy in foxes from a dynamic wetland habitat.

The red fox (Vulpes vulpes) is the most abundant mesopredator in the Central European region. Detailed knowledge about their feeding behavior is important both from ecological and wildlife management reasons. Food choices of foxes are poorly predictable in high-biodiversity marshlands. The main aim of our study was to sample parallel the main food-type abundances in the study area and analyze the diet of fox cubs and cohabiting adults across 3 years during the period of maternal dependence of the cubs. According to the optimal foraging theory, we predicted that the cubs' diet would show higher energy content, would be more varied, and the individual prey species fed to the young would be larger. We analyzed the composition of adult fox and cub fecal samples collected separately around dens in a marshland of western Hungary, May 2014, 2017 and 2020, when the abundance values of main food sources differed. Rodents and waterfowl dominated the diet, but their relative occurrence in the samples showed yearly variations. We found that vixens follow a dual optimizing foraging strategy regarding their provisioning of the cubs and their own diet. Adult foxes optimized their diet according to the actual yearly abundances of their main food sources. Additionally, they preferred prey items that can be consumed at the site of capture (large carrion and small individual prey items). Cubs on the other hand were provisioned with optimal high-energy food, even if those in question became less abundant in that year. Vixens mostly fed to their young either larger rodents and waterfowl, or multiple small rodents at a time-these type of prey are both optimal for transportation as a single load. Providing optimal prey at an early age in a changing environment may contribute to the ecological success of the red fox.

European Pond Turtle (Emys orbicularis) Nest Predation: A Study with Artificial Nests.

Nest predation significantly impacts the population decline of the long-living European pond turtle (Emys orbicularis). Kis-Balaton is one of the most important habitats of this species in Hungary, and in May 2017 more than 400 damaged nests were counted. To reveal predation pressure, we conducted a study with artificial nests on three sites in this area. On each site, we used 11 depredated real nests, and near each of them, we created new artificial nests; then in every nest we put one quail egg, one plasticine egg and several turtle egg shells. After that, we sprayed the smoothed surface of the covered holes with water-diluted turtle urine, imitating the turtle's behaviour. Already in the first three nights, 94% of all nests were depredated by the red fox (Vulpes vulpes) and in one case by the European badger (Meles meles), which was confirmed by the bite marks preserved on the plasticine eggs, by the footprints and excrements found near the nests, as well as by camera recordings. Only 6% of the nests survived during the three weeks of our study. Daily survival rates of quail eggs in artificial nests established in both real (damaged) and in new nests were similar, suggesting that estimates obtained with artificial nests reflect the degree of predation pressure on real nests. On the site where the nests were scattered, their daily survival rate (33%) was significantly lower than on the sites where their arrangement was partly scattered, partly linear (83%), or only linear (76%). On two additional sites, by using simulated turtle nests we showed that spraying the nests with diluted turtle urine and marking them with a flag did not affect their survival, although further methodological testing is needed. The information obtained with artificial nests enables the organization of the protection of the nests of the European pond turtle and selective predator control.

Distribution of microplastics in the catchment region of Pallikaranai marshland, a Ramsar site in Chennai, India.

Microplastics are persistent toxic pollutants, detected in different environmental compartments. Numerous studies on the characteristics and distribution of microplastics present in different environmental matrices are being carried out. However, limited studies have been performed in environmental systems like eco-sensitive freshwater marshlands. Therefore, to enrich the existing knowledge and understanding, this current study has analysed the distribution and characteristics of microplastics present in the catchment region of Pallikaranai marshland, Chennai, India. Both surface water and sediment samples were contaminated with microplastics in the range of 740-2826 items/m3and 700 to 5833 items/kg of dry sediment, respectively. Compared to other shapes, fibrous microplastics were predominant in most of the surface water (n = 11) and sediment (n = 8) samples. The abundant presence of smaller microplastics (<1 mm) in the surface water suggests elevated impacts on the aquatic species owing to their higher bioavailability. Elevated anthropogenic activities and frequent movement of people in urban and residential areas were noted to possibly influence the spatial distribution of microplastics. Furthermore, heavy metals' occurrence on microplastics was investigated using X-Ray Fluorescence Analyser (XRF) and Zn, Fe, Ti, and Ni are the commonly detected (>50% of the samples) elements. The estimated average pollution load index of 2.5 indicates the polluted state of Pallikaranai catchment region.

Maize growth response to different Bacillus strains isolated from a salt-marshland area under salinity stress.

Maize (Zea mays) growth performance has been hindered due to the high soil salinity. Salinity is one of the most severe abiotic stresses that has led to growth imbalance and profitability of harvests in arid and semi-arid regions. Plants have taken advantage of salt-tolerant bacteria as plant growth-promoters to enhance growth and reduce the adverse effects of salinity through the regulation of some biochemical, physiological, and molecular features. Preferences for non-chemical, eco-friendly, and economical approaches have caused the inquiry of the Bacillus genus as a joint group of plant growth-promoting rhizobacteria known to alleviate salt-stress impacts. In the present study, halotolerant Bacillus strains were isolated from salt-marshland soil and characterized for their physiological, molecular, and biochemical properties. Twenty-four bacterial isolates collected from high saline fields of salt marshland were analyzed by MALDI-TOF MS proteome analysis, which confirmed the taxonomic affiliation with Bacillus cereus, Bacillus subtilis, Bacillus atrophaeus, and Bacillus thorngiensis. Applying the isolates on maize plants as bio-inoculant bacteria obviously increased the growth parameters (P < 0.01). Pot experiments showed that isolates 74 and 90 were the most prominent strains to minimize the harmful effects of salinity. Its effects are heightening the potassium/sodium ratio and K-Na selectivity in shoots and roots measured by flame atomic absorption photometry (AAS). Accordingly, Bacillus cereus isolate 74 showed a maximum increase in dry weights of the shoot (133.89%), root (237.08%), length of the shoot (125%), and root (119.44%) compared to the control condition. Our findings suggest that bacteria isolated from marshland may be an economical and simple means to increase plant growth and resistance to high salinity soil conditions.

Efforts to eliminate schistosomiasis in Hubei province, China: 2005-2018.

BACKGROUND: The Hubei province is one of the most schistosomiasis-epidemic-prone provinces in China. A series of strategies were adopted by the government to curb the rebound schistosomiasis endemic status that has prevailed since the early 2000s. This study aimed to elucidate the trends of schistosomiasis transmission and to appraise the effectiveness of the integrated control strategy in lake and marshland areas. METHODS: Surveillance data of schistosomiasis in the Hubei province between 2005 and 2018 were analyzed, including conventional health control measures, integrated strategies, and measures that focused on the infection source. According to the local annual plan for schistosomiasis control in endemic counties, previous measures were human and snail control and surveillance. Residents aged 6-65 years were screened by an immunological detection method called indirect hemagglutination assay (IHA) after the transmission season each year. All residents who tested positive were then asked to provide a fecal sample for examination by the miracidium hatching technique (MHT) to detect the presence of schistosomes. Moreover, systematic snail surveys were conducted as a part of the combined environmental sampling method. The latter included integrated strategies and measures that focused on the infection source. Bovine stool samples were also collected and concurrently assessed using the MHT by the agriculture department, river-hardening slope protection was constructed by the water conservancy department, and forestation promotion was conducted by the forest department. The effectiveness of the integrated control strategy was assessed using two indicators of resident and livestock infection rates and three indicators of snail epidemics across all endemic areas. RESULTS: From 2005 to 2018, a total of 28. 46 million and 2. 05 million residents were assessed by immunological (IHA) and etiological (MHT) detection techniques, respectively. Snail surveys and molluscicide application were performed in 2. 26 hectares and 0. 37 hectares, respectively. Moreover, 2. 60 million bovines were assessed by etiological detection techniques (MHT). The river-hardening slope protection project was implemented in 503 places, and 46 thousand hectares in endemic areas underwent environmental modification. Forestation was implemented at an area of 0. 15 million hectares. Between 2005 and 2018, the epidemic indicators, including resident and livestock infection rates and the infested areas and infection rate of snails, all presented downward trends. The resident infection rate decreased from 3. 78% in 2005 to 0% in 2016, which persisted through 2018. The livestock infection rate decreased from 5. 63% in 2005 to 0% in 2013, which also persisted through 2018. From 2005 to 2018, the snail-inhabited area was slightly reduced, but the area of infected snails decreased to 0 in 2012; this persisted through 2018. All counties met the goal for schistosomiasis infection control, transmission control, and disruption of schistosomiasis activity in 2008, 2013, and 2018 separately. That means the goal has been achieved in each stage. CONCLUSIONS: The decline of the schistosomiasis epidemic rate demonstrates that the Chinese government was successful in meeting its public health goal in Hubei province. In the next decade, precision interventions must be implemented in endemic counties with a relatively low epidemic status to achieve the goals of the Outline of the Healthy China 2030 Plan. A similar strategy can be applied in other countries to eliminate schistosomiasis globally.

[Comparison of pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province].

OBJECTIVE: To compare the differences in pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province, so as to provide the scientific evidence for formulating the precise schistosomiasis control strategy in different endemic foci. METHODS: C57BL/6 mice were infected with cercariae of S. japonicum isolates from Shitai County (hilly regions) and Susong County (marshland and lake regions) of Anhui Province in 2021, and all mice were sacrificed 44 days post-infection and dissected. The worm burdens, number of S. japonicum eggs deposited in the liver, and the area of egg granulomas in the liver were measured to compare the difference in the pathogenicity between the two isolates. In addition, female and male adult S. japonicum worms were collected and subjected to transcriptome sequencing, and the gene expression profiles were compared between Shitai and Susong isolates of S. japonicum. The differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. RESULTS: The total worm burdens [(14.50 ± 3.96) worms/mouse vs. (16.10 ± 3.78) worms/mouse; t = 0.877, P = 0.392], number of female and male paired worms [(4.50 ± 0.67) worms/mouse vs. (5.10 ± 1.45) worms/mouse; t = 1.129, P = 0.280], number of unpaired male worms [(5.50 ± 4.01) worms/mouse vs. (5.60 ± 1.69) worms/mouse; t = 0.069, P = 0.946], number of eggs deposited in per gram liver [(12 116.70 ± 6 508.83) eggs vs. (16 696.70 ± 4 571.56) eggs; t = 1.821, P = 0.085], and area of a single egg granuloma in the liver [(74 359.40 ± 11 766.34) µm2 vs. (74 836.90 ± 13 086.12) µm2; t = 0.081, P = 0.936] were comparable between Shitai and Susong isolates of S. japonicum. Transcriptome sequencing identified 584 DEGs between adult female worms and 1 598 DEGs between adult male worms of Shitai and Susong isolates of S. japonicum. GO enrichment analysis showed that the DEGs between female adults were predominantly enriched in biological processes of stimulus response, cytotoxicity, multiple cell biological processes, metabolic processes, cellular processes and signaling pathways, cellular components of cell, organelles and cell membranes and molecular functions of binding and catalytic ability, and KEGG enrichment analysis showed that these DEGs were significantly enriched in pathways of vascular endothelial growth factor signaling, glutathione metabolism, arginine and proline metabolism. In addition, the DEGs between male adults were predominantly enriched in biological processes of signaling transduction, multiple cell biological processes, regulation of biological processes, metabolic processes, development processes and stimulus responses, cellular components of extracellular matrix and cell junction and molecular functions of binding and catalytic ability, and these DEGs were significantly enriched in pathways of Wnt signaling, Ras signaling, natural killer cells-mediated cytotoxicity, extracellular matrix-receptor interactions and arginine biosynthesis. CONCLUSIONS: There is no significant difference in the pathogenicity between S. japonicum isolates from hilly and marshland and lake regions of Anhui Province; however, the gene expression profiles vary significantly between S. japonicum isolates.

Comparison of pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province / 中国血吸虫病防治杂志

Objective To compare the differences in pathogenicity and gene expression profiles between adult Schistosoma japonicum isolated from hilly and marshland and lake regions of Anhui Province, so as to provide the scientific evidence for formulating the precise schistosomiasis control strategy in different endemic foci. Methods C57BL/6 mice were infected with cercariae of S. japonicum isolates from Shitai County (hilly regions) and Susong County (marshland and lake regions) of Anhui Province in 2021, and all mice were sacrificed 44 days post-infection and dissected. The worm burdens, number of S. japonicum eggs deposited in the liver, and the area of egg granulomas in the liver were measured to compare the difference in the pathogenicity between the two isolates. In addition, female and male adult S. japonicum worms were collected and subjected to transcriptome sequencing, and the gene expression profiles were compared between Shitai and Susong isolates of S. japonicum. The differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Results The total worm burdens [(14.50 ± 3.96) worms/mouse vs. (16.10 ± 3.78) worms/mouse; t = 0.877, P = 0.392], number of female and male paired worms [(4.50 ± 0.67) worms/mouse vs. (5.10 ± 1.45) worms/mouse; t = 1.129, P = 0.280], number of unpaired male worms [(5.50 ± 4.01) worms/mouse vs. (5.60 ± 1.69) worms/mouse; t = 0.069, P = 0.946], number of eggs deposited in per gram liver [(12 116.70 ± 6 508.83) eggs vs. (16 696.70 ± 4 571.56) eggs; t = 1.821, P = 0.085], and area of a single egg granuloma in the liver [(74 359.40 ± 11 766.34) µm2 vs. (74 836.90 ± 13 086.12) µm2; t = 0.081, P = 0.936] were comparable between Shitai and Susong isolates of S. japonicum. Transcriptome sequencing identified 584 DEGs between adult female worms and 1 598 DEGs between adult male worms of Shitai and Susong isolates of S. japonicum. GO enrichment analysis showed that the DEGs between female adults were predominantly enriched in biological processes of stimulus response, cytotoxicity, multiple cell biological processes, metabolic processes, cellular processes and signaling pathways, cellular components of cell, organelles and cell membranes and molecular functions of binding and catalytic ability, and KEGG enrichment analysis showed that these DEGs were significantly enriched in pathways of vascular endothelial growth factor signaling, glutathione metabolism, arginine and proline metabolism. In addition, the DEGs between male adults were predominantly enriched in biological processes of signaling transduction, multiple cell biological processes, regulation of biological processes, metabolic processes, development processes and stimulus responses, cellular components of extracellular matrix and cell junction and molecular functions of binding and catalytic ability, and these DEGs were significantly enriched in pathways of Wnt signaling, Ras signaling, natural killer cells-mediated cytotoxicity, extracellular matrix-receptor interactions and arginine biosynthesis. Conclusions There is no significant difference in the pathogenicity between S. japonicum isolates from hilly and marshland and lake regions of Anhui Province; however, the gene expression profiles vary significantly between S. japonicum isolates.

Spatiotemporal distribution of oncomelania hupensis snail habitats in the Middle and Lower Reaches of the Yangtze River / 公共卫生与预防医学

Schistosomiasis is one of the major communicable diseases, which seriously impacts human health, Oncomelania hupensis snail is unique intermediate host of Schistosoma japonicum as well as posts significant influence on schistosomiasis transmission. The long-term serial data of oncomelania snail area in the Middle and Lower Reaches of the Yangtze River in the Schistosomiasis situation in People's Republic of China ,were collected from 1999 to 2018. The spatial and temporal variation characteristics of oncomelania hupensis area in five provinces were analyzed by Manner-Kendall test. In the spatial change, the area composition ratio of lake-and-marshland regions in Hunan increased, while that in Hubei and Jiangxi showed a slight decline. The lake-and-marshland snails in Anhui showed a significant downward trend, while Jiangsu showed no stable trend. In the spatial change, the area of lake-and-marshland snails in Jiangsu, Anhui, and Hubei showed a downward trend, among which the downward trend in Hubei was not obvious, while the upward trend in Jiangxi and Hunan had an upward trend but the trend was not obvious. the year of the sudden change in the area of the lake and marshes in in Jiangsu and Hubei were 2010 and 2017 ; There was no significant mutation in Anhui Province; the mutation point of the lake-and-marshland snails in Hunan was between 2001 and 2002; the mutation year of the lake-and-marshland snails in Jiangxi was 2002.This paper studies the temporal and spatial changes of the snail breeding area in the middle and lower Yangtze River, and the results can provide a basis for the elimination of snails in different types of distribution areas.

[Impact of water body environments on the microbial community of Oncomelania hupensis snails in marshlands around the eastern Dongting Lake].

OBJECTIVE: To evaluate the effects of water body environments on the microbial community of Oncomelania hupensis snails in marshlands of the eastern Dongting Lake where natural extinction of O. hupensis snails are found, so as to explore the correlation between the natural extinction of O. hupensis snails and the microbial community in snails. METHODS: Snails were caged water bodies in the Qianliang Lake marshland (Qianliang Lake regions) where natural extinction of snails was found and in the Junshan Park marshland (Junshan Park regions) in the eastern Dongting Lake for 30 days, and then all snails were collected and identified for survival or death. DNA sequencing of the fungi and bacteria was performed in snails before and after immersion in waters, and the biodiversity and abundance were analyzed. RESULTS: The survival rates of O. hupensis snails were 28.0% (70/250) and 64.8% (162/250) in Qianliang Lake regions and Junshan Park regions 30 days after immersion in waters, respectively (χ2 = 81.365, P < 0.01). The number of the fungal community and the biodiversity of the bacterial community were both greater in snails caged in Qianliang Lake regions post-immersion than pre-immersion, and there was a significant difference in the structure of the fungal and bacterial communities. The microbial community with a significant difference included Flavobacteriaceae,which was harmful to O. hupensis snails. CONCLUSIONS: The water body environment affects the composition of the microbial community in O. hupensis snails in marshlands with natural snail distinction around the eastern Dongting Lake; however, further studies are required to investigate whether the natural distinction of snails is caused by water body environments-induced changes of the microbial spectrum in O. hupensis snails.

Impact of water body environments on the microbial community of Oncomelania hupensis snails in marshlands around the eastern Dongting Lake / 中国血吸虫病防治杂志

Objective To evaluate the effects of water body environments on the microbial community of Oncomelania hupensis snails in marshlands of the eastern Dongting Lake where natural extinction of O. hupensis snails are found, so as to explore the correlation between the natural extinction of O. hupensis snails and the microbial community in snails. Methods Snails were caged water bodies in the Qianliang Lake marshland (Qianliang Lake regions) where natural extinction of snails was found and in the Junshan Park marshland (Junshan Park regions) in the eastern Dongting Lake for 30 days, and then all snails were collected and identified for survival or death. DNA sequencing of the fungi and bacteria was performed in snails before and after immersion in waters, and the biodiversity and abundance were analyzed. Results The survival rates of O. hupensis snails were 28.0% (70/250) and 64.8% (162/250) in Qianliang Lake regions and Junshan Park regions 30 days after immersion in waters, respectively (χ2 = 81.365, P < 0.01). The number of the fungal community and the biodiversity of the bacterial community were both greater in snails caged in Qianliang Lake regions post-immersion than pre-immersion, and there was a significant difference in the structure of the fungal and bacterial communities. The microbial community with a significant difference included Flavobacteriaceae,which was harmful to O. hupensis snails. Conclusion The water body environment affects the composition of the microbial community in O. hupensis snails in marshlands with natural snail distinction around the eastern Dongting Lake; however, further studies are required to investigate whether the natural distinction of snails is caused by water body environments-induced changes of the microbial spectrum in O. hupensis snails.

[Effectiveness of snail control by immersion of molluscicides through tide diversion in marshlands: a field evaluation].

OBJECTIVE: To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. METHODS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. RESULTS: The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. CONCLUSIONS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.

Marshland restoration benefits Collembola recruitment: a long-term chronosequence study in Sanjiang mire marshland, China.

To examine the biodiversity restoration of marshlands after human-induced disturbances, a long-term chronosequence study of Collembola communities was completed that included cultivated treatment (marshes with 15 years of soybean cultivation; CU15), two restored treatments (with 6 and 12 years of agricultural abandonment; RE06 and RE12, respectively), and an intact marshland (IM) as a reference in the Sanjiang Plain, Northeastern China. Changes in the soil properties and Collembola communities under different treatments were analyzed. Soil parameters (i.e., soil organic carbon, available N, P and K, soil moisture) significantly increased from the cultivated treatment to the 6-year agricultural abandoned, and then 12-year agricultural abandoned treatment, indicating that the degraded soil began to recover after agricultural abandonment. The density, species richness and diversity of Collembola in RE12 were significantly higher than in RE06 and CU15, and even surpass the IM, indicating marshland restoration (after 12 years of agricultural abandonment) benefited recruitment and reconstruction of Collembola community. We found soil surface-dwelling Collembola recovered faster than eu-edaphic species, that is probably due to some common traits (i.e., parthenogenesis and fast dispersal) between epi- and hemi-edaphic species. The changes in the vegetation and soil properties during long-term soybean cultivation and agricultural abandonment were the key factors affecting the composition, density, and species richness of soil Collembola.

Effectiveness of snail control by immersion of molluscicides through tide diversion in marshlands: a field evaluation / 中国血吸虫病防治杂志

Objective To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. Methods Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. Results The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. Conclusion Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.

Effectiveness of snail control by immersion of molluscicides through tide diversion in marshlands: a field evaluation / 中国血吸虫病防治杂志

Objective To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. Methods Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. Results The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. Conclusion Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.

[Molluscicidal effects of different formulations of niclosamide ethanolamine salt in marshlands].

OBJECTIVE: To evaluate the molluscicidal effects of different formulations of niclosamide ethanolamine salt in marshlands. METHODS: The molluscicidal effects of spraying with 25% suspension concentrate of niclosamide ethanolamine salt (25% SCN) and 50% wettable powder formulation of niclosamide ethanolamine salt (50% WPN), and dusting with 4% niclosamide ethanolamine salt dustable powder (4% DP) for controlling Oncomelania hupensis snails were investigated and compared in the fields, and the cost-effectiveness was analyzed. RESULTS: The corrected mortalities and the reduced rates of density of snails were 54.37%, 91.70%, 92.76%, 79.50%, and 59.55%, 95.93%, 97.63%, 94.15%, respectively, on 3, 7, 15, 30 d after spaying with 25% SCN, those on 3, 7, 15, 30 d after dusting with 4% DP were 59.10%, 91.83%, 95.56%, 93.34% and 65.03%, 94.93%, 97.61%, 97.28%, respectively; and those on 3, 7, 15, 30 d after spraying with 50% WPN were 76.29%, 91.68%, 93.12%, 81.59% and 81.24%, 97.02%, 97.84%, 95.27%, respectively. The cost of spraying with 25% SCN was 0.21 Yuan/m2, that of dusting with 4% DP was 0.39 Yuan/m2, and that of spraying with 50% WPN was 0.23 Yuan/m2 for snail control in the marshland. The cost of reduced one percentage of the corrected mortalities and the density of snails in controlling snails by 25% SCN, 4% DP and 50% WPN on 15 d were 22.68, 40.63, 25.17 Yuan and 21.54, 39.78, 23.95 Yuan, respectively. CONCLUSIONS: The three different formulations of niclosamide are reliable and effective for snail control in marshlands. There are some differences among the different molluscicides in start time, pharmacodynamic characteristics, spraying methods in the field, cost of snail control, and influencing factors. Therefore, we need reasonably select the suitable molluscicides according to the environmental characteristics and working condition.

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

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

[Field molluscicidal effect of water-free formulations of niclosamide ethanolamine salt against Oncomelania hupensis snails in a marshland].

OBJECTIVE: To evaluate the molluscicidal effects of various water-free formulations of niclosamide ethanolamine salt against Oncomelania hupensis in the field of marshlands along the Yangtze River. METHODS: The river beach with O. hupensis snails were selected as the test field in the marshland along the Yangtze River in Pukou District, Nanjing City. A molluscicidal experiment was carried out by the mechanical dusting method with the dustable powder (DP), powder-granule (PG), granule (GR) of niclosamide ethanolamine salt respectively. The snail mortality, corrected mortality, and the reduced rate of snails' density were parallel compared among DP, PG and GR. RESULTS: On the 3rd day after the dusting, the snail mortality rates were 66.67%, 67.24%, and 66.87% in the DP, PG, and GR groups respectively, on the 7th day after the dusting, the snail mortality rates were 75.36%, 79.73%, and 73.97% in the DP, PG, and GR groups respectively, and there was no significant difference among the groups (χ2 = 0.006, 0.895, both P > 0.05). On the 15th day after the dusting, the snail mortality rates were 86.92%, 72.86%, and 71.43% in the DP, PG, and GR groups respectively, and there was a significant difference among the groups (χ2 = 9.709, P < 0.01). The snail mortality in the DP group was significantly higher than that in the PG, and GR groups. The curves of the snail corrected mortality and reduced rate of snails'density presented steadily rising trends in the DP group, but presented falling trends in the PG and GR groups on the 15th day after the dusting. CONCLUSIONS: The molluscicidal effect of DP is stable and effective in the marshland along the Yangtze River, but the drift of the powder is still not effectively controlled. It is necessary that the different dosage forms are perfected.

[Changes of serum anti-schistosome antibody levels in schistosomiasis japonica patients after treatment].

OBJECTIVE: To investigate the changes of serum anti-schistosome antibody titers in schistosomiasis japonica patients after treatment, in order to provide the evidence for formulating the schistosomiasis surveillance program in marshland and lake regions. METHODS: Upon prospective cohort study, the stool examination positive schistosomiasis patients and blood examination positive suspected patients (the titer was more than 1:80, including 1:80) were selected as the research objects in Jiangling County in 2014, and they received the 2-day praziquantel therapy. Half year, one year and two years after the treatment, their blood samples and fecal samples were collected for IHA anti-schistosome antibody detections and schistosome egg and miracidium detections. RESULTS: In 2014, the stool examination positives were 251, and the majority of them were over 41 years old, accounting for 93.23% (234/251) ; 581 cases of high antibody titers were detected by the IHA method, and the majority of them were over 41 years old, accounting for 89.16% (518/581) . Half year, one year and two years after the treatment, among the stool examination positives, the negative conversion rates of stool positives were 99.60% (250/251), 100% (239/239) and 100% (234/234) respectively and the negative conversion rates of antibody positives were 21.91% (55/251), 64.11% (156/239) and 76.89% (193/234) respectively. In the high antibody titer positives, the negative conversion rates were 38.04% (221/581), 64.11% (359/560), and 77.86% (429/551) respectively, Half year, one year and two years after the treatment. There were statistically significant differences among the antibody negative conversion rates by χ2 test (χ2 = 77.538, 183.412, 25.469 respectively, all P < 0.001) . The geometric mean values of antibody titers of different durations between 2 groups were analyzed by 2-independent-samples T test, and the geometric mean values of antibody titers between the 2 groups were different before the treatment (t = 23.576, P < 0.01), but the geometric mean values of antibody titers between the 2 groups were not different 6 months, 1 year and 2 years after the treatment (t = -0.046, 1.165, -0.132, P = 0.964, 0.245, 0.895 respectively). CONCLUSIONS: The levels of serum anti-schistosome antibody degrade slowly in schistosomiasis japonica patients after the treatment, and the results of IHA tests cannot distinguish the current schistosome infection from previous schistosome infection. Therefore, it is necessary to develop the specific diagnostic technology for schistosome infection in order to meet the need of monitoring.

Molluscicidal effects of different formulations of niclosamide ethanolamine salt in marshlands / 中国血吸虫病防治杂志

Objective To evaluate the molluscicidal effects of different formulations of niclosamide ethanolamine salt in marshlands. Methods The molluscicidal effects of spraying with 25% suspension concentrate of niclosamide ethanolamine salt (25% SCN) and 50% wettable powder formulation of niclosamide ethanolamine salt (50% WPN), and dusting with 4% niclosamide ethanolamine salt dustable powder (4% DP) for controlling Oncomelania hupensis snails were investigated and compared in the fields, and the cost-effectiveness was analyzed. Results The corrected mortalities and the reduced rates of density of snails were 54.37%, 91.70%, 92.76%, 79.50%, and 59.55%, 95.93%, 97.63%, 94.15%, respectively, on 3, 7, 15, 30 d after spaying with 25% SCN, those on 3, 7, 15, 30 d after dusting with 4% DP were 59.10%, 91.83%, 95.56%, 93.34% and 65.03%, 94.93%, 97.61%, 97.28%, respectively; and those on 3, 7, 15, 30 d after spraying with 50% WPN were 76.29%, 91.68%, 93.12%, 81.59% and 81.24%, 97.02%, 97.84%, 95.27%, respectively. The cost of spraying with 25% SCN was 0.21 Yuan/m2, that of dusting with 4% DP was 0.39 Yuan/m2, and that of spraying with 50% WPN was 0.23 Yuan/m2 for snail control in the marshland. The cost of reduced one percentage of the corrected mortalities and the density of snails in controlling snails by 25% SCN, 4% DP and 50% WPN on 15 d were 22.68, 40.63, 25.17 Yuan and 21.54, 39.78, 23.95 Yuan, respectively. Conclusions The three different formulations of niclosamide are reliable and effective for snail control in marshlands. There are some differences among the different molluscicides in start time, pharmacodynamic characteristics, spraying methods in the field, cost of snail control, and influencing factors. Therefore, we need reasonably select the suitable molluscicides according to the environmental characteristics and working condition.