ABSTRACT
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.
ABSTRACT
Objective To investigate the effects and cost of four formulations of niclosamide ethanolamine salt in Oncomela-nia hupensis snail control in the field in marshland and lake regions,so as to provide the evidence for drawing up the plan of mol-luscicide using in schistosomiasis endemic areas. Methods One drainage channel and one channel without water in the same area with snails in Jiangling County,Jingzhou City were selected as the research fields. The drainage channel was divided into 9 sections,except one section as a blank control group where the natural death rate of snails was observed only,and the remaining 8 sections were taken as the observation groups,where different dosages of 4％niclosamide ethanolamine salt powder,5％ni-closamide ethanolamine salt granules,25％ niclosamide ethanolamine salt suspending agent,26％ metaldehyde and ni-closamide ethanolamine salt suspending agent,and 50％niclosamide ethanolamine salt wettable powder were used re-spectively. The channel without water were divided into 4 sections,except one section as a blank control group,the oth-er 3 segments were taken as the observation groups,where 4％niclosamide ethanolamine salt powder,5％niclosamide ethanolamine salt granules,and 50％ niclosamide ethanolamine salt wettable powder were used respectively. Before and after spraying molluscicide for 7 days and 15 days,the system sampling method was used to observe the effects of snail control. Meanwhile,the unit cost method was used to calculate the costs of the different mulluscicide formulations abovementioned in unit area(1 m2). Results In the field at the drainage channel,the snail mortality rates of the groups spraying 4％niclosamide ethanolamine salt powder(50 g/m2),5％niclosamide ethanolamine salt granules(40 g/m2),25％ niclosamide ethanolamine suspending agent,26％ metaldehyde and niclosamide ethanolamine salt sus-pending agent,and 50％niclosamide ethanolamine salt wettable powder(2 g/m2 and 4 g/m2)for 7 days were 79.52％-97.87％,while the rates after spraying for 15 days were 71.00％-96.30％,and compared with those before spraying, the differences were statistically significant(all P<0.01). For the groups spraying with 2 g/m2 or 4 g/m2 suspending agent as well as wettable powder for 7 days,the snail mortality rates were significantly different(both P<0.05). In the field at the channel without water,the snail mortality rates of the 3 observation groups after spraying molluscicide for 7 days were 97.14％-100％,while for 15 days were 94.32％-100％,and compared with the rates before spraying,all the differences were statistically significant(all P<0.01). The unit costs per 1 m2 of the molluscicide abovementioned were ranged from 0.280 Yuan to 0.416 Yuan. Conclusions In marshland area inside embankment,the molluscicide formulations of the powder and granule are suitable for the environments without water or with instability water level , while the molluscicide formulations of the suspended agents and wettable powder are suitable for the water environment. Though the unit cost of powder is the lowest,the molluscicide in this formulation flies away seriously.
ABSTRACT
Objective To evaluate the effects of 3 molluscicides namely 5%niclosamide ethanolamine granules,4%“Luo-wei”(Tea-seed distilled saponins,TDS)and 50%wettable powder of niclosamide ethanolamine salt(WPN)by spraying and pou-drage methods in marshland and lake regions in dry season. Methods An environment with a high snail density was chosen as the experimental field,then the spraying and poudrage experiments were carried out in the field to assess the molluscicidal effects of 5%niclosamide ethanolamine granules,TDS and WPN delivered by spraying and poudrage methods with a concentration of 30, 6 and 2 g/m2,respectively,and the molluscicidal effects of the 3 drugs by the two methods were evaluated and compared in differ-ent time. Results After the delivery for 15 d,the adjusted snail death rates of the 5%niclosamide ethanolamine granules,TDS and WPN in the spraying experiment were 79.00%,82.29%and 84.83%,respectively,and those in the poudrage experiments were 97.42%,95.27% and 96.62%,respectively. Conclusion The molluscicidal effect of poudrage method is better than the spraying method,and the former is worthy of further extension and application in the marshland in dry season.
ABSTRACT
Objective To evaluate the schistosomiasis control effect of the measures of replacing cattle with machine for cul?tivation and forbidding depasturage of livestock on marshlands in marshland and lake regions. Methods The retrospective re?view 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 hu?man,cattle,and Oncomelania hupensis snails,and schistosome?infested field excreta were surveyed from 2007 to 2013. The ef?fects 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 imple? mented 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,P0.05). 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 sig?nificantly 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.
ABSTRACT
Objective To analyze the time and space aggregation of acute schistosome infections in marshland and lake areas in five provinces(Jiangsu,Anhui,Jiangxi,Hubei and Hunan province)from 2005 to 2012,so as to provide the evidence for es-tablishing control strategies and taking effective control measures. Methods The data of patients with acute schistosome infection in marshland and lake areas in five provinces from 2005 to 2012 were collected and analyzed with the concentration ratio and circu-lar distribution methods for the epidemic season features and time aggregation of the infection,and with the spatial autocorrelation analysis for the space aggregation of the infected cases. Results According to the concentration ratio,the occurrence of acute schistosome infection had strong seasonality,and the concentration ratio was 0.758;according to the circular distribution method, the peak day of acute schistosome infections was 10th,August. The spatial analysis suggested that the infected cases highly gath-ered around Poyang Lake,Dongting Lake and Yangtze River Basin in 23 counties of the five provinces,and the result of spatial au-tocorrelation analysis showed that the spatial autocorrelation index I was 0.16(P=0.01). Conclusion The occurrence of acute schistosome infections in lake regions of the 5 provinces shows strong seasonality and space aggregation,therefore we can bring the control mark forward,and take targeted prevention and control measures in high aggregation areas of acute schistosomiasis.
ABSTRACT
Objective To evaluate the cost-effectiveness of the comprehensive control measures carrying out in schistosomia-sis endemic inner embankment of marshland and lake regions from 2006 to 2010,so as to provide the reference for further rational allocation of limited health resources and ultimately speeding up the procedure of schistosomiasis elimination. Methods With ref-erence to the requirements of the national schistosomiasis transmission control and phase goals for schistosomiasis control in Hubei Province,Jiangling County,one schistosomiasis control pilot of Hubei Province combined with the National Health and Family Planning Commission and Ministry of Agriculture,was selected for the study. A definition of the infection rates of human and do- mestic animals was used for endemic villages stratified by different layers(i.e.,the village with the infection rates of human and domestic animals ≥3% belonged to the first layer,≥ 1% belonged to the second layer;<1% belonged to the third layer). By us- ing the stratification method and cost-effectiveness analysis,the endemic villages stratified with the different layers were investi- gated and all the data of schistosomiasis endemic situation,cost and effectiveness of schistosomiasis control were collected and comprehensively analyzed from 2006 to 2010. Results In the effectiveness of schistosomiasis control,by the end of 2010, there were no first layer villages,there were 114 second layer villages,and there were 18 third layer villages in Jiangling Coun- ty. In the former first layer villages,the schistosomiasis patients decreased year by year ultimately to 0;but in the second and third layer villages,the schistosomiasis patients increased. In the fecal treatment and management,the coverage rates of harm- less sanitary latrines were 27.45% in 2009 and 48.74% in 2010 respectively in the second layer villages,whereas there were no harmless sanitary latrines in the first and third layer villages. In the 5 years,the input of comprehensive control measures was 10 266 3900 Yuan,much higher than the human and buffalo examinations and treatments,Oncomelania hupensis snail investi- gation and elimination(4 183 000 Yuan)and other labor inputs(2 239 500Yuan). In the ratio of cost-effectiveness,the annual ratio of unit cost(1% reduction of human and buffalo infection and 1 hm2 reduction of snail areas)increased yearly. In addition, the semi-logarithmic stability trend analysis of health inputs and cost showed that there was a stable balance between inputs and cost in the different layers(logarithmic values of any two layers of pair-wise comparison were <1,and in the third layer villages, the annual average logarithmic values of 5 years were <1). Whereas,in the first and second layer villages,the annual average cost was fluctuated(the costs was higher than the inputs). Conclusion The schistosomiasis situation is reduced year by year in Jiangling County from 2006 to 2010. Whereas,the main infection source(buffaloes)still exists and the present control mea- sures including fecal management should be further strengthened. In the resource allocation,in the field of health,the annual distribution of key inputs and unit-cost control also has a further space of adjustment.