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OBJECTIVE@#To improve the understanding of the virome and bacterial microbiome in the wildlife rescue station of Poyang Lake, China.@*METHODS@#Ten smear samples were collected in March 2019. Metagenomic sequencing was performed to delineate bacterial and viral diversity. Taxonomic analysis was performed using the Kraken2 and Bracken methods. A maximum-likelihood tree was constructed based on the RNA-dependent RNA polymerase (RdRp) region of picornavirus.@*RESULTS@#We identified 363 bacterial and 6 viral families. A significant difference in microbial and viral abundance was found between samples S01-S09 and S10. In S01-S09, members of Flavobacteriia and Gammaproteobacteria were the most prevalent, while in S10, the most prevalent bacteria class was Actinomycetia. Among S01-S09, members of Myoviridae and Herelleviridae were the most prevalent, while the dominant virus family of S10 was Picornaviridae. The full genome of the pigeon mesivirus-like virus (NC-BM-233) was recovered from S10 and contained an open reading frame of 8,124 nt. It showed the best hit to the pigeon mesivirus 2 polyprotein, with 84.10% amino acid identity. Phylogenetic analysis showed that RdRp clustered into Megrivirus B.@*CONCLUSION@#This study provides an initial assessment of the bacteria and viruses in the cage-smeared samples, broadens our knowledge of viral and bacterial diversity, and is a way to discover potential pathogens in wild birds.
Subject(s)
Animals , Animals, Wild/genetics , Lakes , Phylogeny , Picornaviridae/genetics , Viruses/genetics , China , Metagenomics , Genome, ViralABSTRACT
Objective To investigate the prevalence of Schistosoma japonicum infections in Elaphurus davidianus released to Poyang Lake areas and evaluate the impact of the project of “E. davidianus released to wild environments for natural reproduction and growth” “(E. davidianus return home project”) on the transmission of schistosomiasis in Poyang Lake areas. Methods During the period from April 2018 to December 2019, the population distribution, inhabiting activity and natural reproduction of E. davidianus released to Poyang Lake areas were investigated by means of GPS and artificial observations. The S. japonicum infection was identified in animal feces in E. davidianus inhabitats using a hatching test, and snail distribution was surveyed in E. davidianus inhabiting grass islands using a systematic sampling method. Results A total of 51 E. davidianus were released to the Poyang Lake areas in 2018, which subsequently produced 5 E. davidianus habitats in Yinlong Lake, Longkou, Nanchi Lake, Lianzi Lake and Zhu Lake. E. davidianus was found to predominantly inhibit in grass islands, farmlands and forest lands in hilly regions around the Poyang Lake areas. The natural reproduction rate of E. davidianus was 25% in the habitats in 2019, and the mean density of snails was 0.009 to 0.039 snails/0.1 m2 in E. davidianus inhabitats; however, no S. japonicum infection was identified in snails. In addition, the mean densities of wild E. davidianus and bovine feces were 4.6 samples/hm2 and 2.1 samples/hm2, Conclusions The E. davidianus released to Poyang Lake areas may get infections with S. japonicum, and cause schistosomiasis transmission through fecal contamination in grass islands. The impact on and the prevalence of S. japonicum infection was 4.35% and 13.16% (P = 0.236), respectively; however, the intensities of S. japonicum infections were “+++” and “+”, respectively. Conclusions The E. davidianus released to Poyang Lake areas may get infections with S. japonicum, and cause schistosomiasis transmission through fecal contamination in grass islands. The impact on local schistosomiasis transmission and the response strategy requires to be investigated following the release of E. davidianus to lake regions, to ensure the achievement of the goal of schistosomiasis elimination and the successful implementation of the “E. davidianus return home project” in Poyang Lake areas.
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Objective To establish a scientific, operational monitoring and early warning index system for schistosomiasis, so as to provide scientific evidence for promoting the scientification and standardization of early warning system in Poyang Lake Eco-economic Region. Methods Two rounds of Delphi experts’ interviews were applied to construct Index system. The weight value of each indicator was determined by the Analytic Hierarchy process and improvable proportionate allocation method. Reliability, validity of index system and the rationality of index weight distribution can be evaluated in site investigation. Results The Index system included 3 first-order indicators, 9 second-order indicators, and 35 third-order indicators. The 3 first-order indicators were endemic status, environmental and social factors, control measures, with the weight value of 0.531 0, 0.101 5 and 0.367 5, respectively. For the 9 second-order indicators, the highest weight value was for Infection status of human and livestock (0.179 5)and the lowest for social factors(0.050 6). During site investigation, the Cronbach’s alpha and spit half reliability of the total index system and three first-order indicators were all over 0.90, the Kendall W coefficient for the data collected in site investigation and Delphi consultation was 0.742 (P=0.018). Conclusions The Monitoring and Early Warning Index System for Schistosomiasis is suitable for the infection status of Poyang Lake Eco-economic region. The reliability and validity of index system are satisfactory, and the indicator weight distribution is rational.
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Ticks are the vectors of various pathogens, threatening human health and animal production across the globe. Here, for the first time we detected Ricketssia spp., Borrelia spp. and protozoan in ticks from Poyang Lake region in Jiangxi Province of eastern China. In 3 habitat categories and on 12 host species, 311 ticks from 11 species were collected. Haemaphysalis longicornis was the predominant species, accounting for 55.63%, followed by Rhipicephalus microplus, Haemaphysalis flava and Ixodes granulatus. Of the collected ticks, 7.07% were positive for tick-borne pathogens, and H. longicornis and H. flava were found to be co-infected with Ricketssia spp. and protozoan. H. flava was the most detected positive for tick-borne pathogens, whereas H. longicornis had the lowest infection rate, and the difference in infection rates between tick species was significant (χ²=61.24, P < 0.001). Furthermore, adult ticks demonstrated remarkably greater infection rate than immature ticks (χ²=10.12, P=0.018), meanwhile ticks on Erinaceidae showed significantly higher positivity than ticks collected on other host species (χ²=108.44, P < 0.001). Genetic fragment sequencing and analyses showed at least 4 pathogen species presence in ticks, namely Borrelia yangtzensis, Rickettsia slovaca or Rickettsia raoultii related genospecies, Babesia vogeli and Hepatozoon canis or Hepatozoon felis related genospecies. The finding indicates that the abundant ticks can carry diverse pathogens in Poyang Lake region, and pathogen infection is highly related to species, vertebrate hosts and life stages of ticks.
Subject(s)
Adult , Animals , Cats , Humans , Babesia , Borrelia , China , Ecosystem , Epidemiology , Felis , Hedgehogs , Ixodes , Lakes , Rhipicephalus , Rickettsia , Risk Factors , Ticks , VertebratesABSTRACT
Objective To grasp the distribution status of Oncomelania hupensis snails in Poyang Lake area,so as to provide the evidence for formulating and adjusting the schistosomiasis prevention and control strategy in lake areas. Methods The vec-tor grid was created and sampled randomly by 200 m × 200 m in the spatial database of grassland,and the distribution of snails was investigated in the selected grid by using the method of mechanical sampling by 50 m × 50 m. At the same time,the eleva-tion of investigation points was extracted based on the topographic map of Poyang Lake. Results Totally 949 and 210 investiga-tion points were collected from the south and north of Poyang Lake areas,accounting for 3.04%and 3.21%of all the investiga-tion points in the respective region. The number of investigation points,the appearance rate of snail frame,and the average den-sity of alive snails were 15231,8.15%,and 0.463/0.1 m2,respectively. The elevation of snail distribution area of the south and north Poyang Lake areas were 11-16 m and 9-16 m respectively. The elevation of concentrated snail belts of the south Poyang Lake area were 12-13 m and 15-16 m,and the elevation of concentrated snail belts of the north Poyang Lake area was 12-14 m. Conclusions The distribution of snails is in the range of 9-16 m. The suitable habitats of snail breeding are moving from the south Poyang Lake area to the north Poyang Lake area,and from high elevation to low elevation. In the future,the schistosomia-sis prevention and control measures could be formulated based on the geographical characteristics of current snail distribution in order to consolidate the achievements of schistosomiasis control.
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Objective To understand the present situation of the chronic schistosomiasis patients'knowledge,attitude and practice on schistosomiasis control in Nanchang City. Methods The knowledge,attitude and values on schistosomiasis control of 523 chronic schistosomiasis patients in Nanchang County,Jinxian County and Xinjian District in the Poyang Lake District were investigated with questionnaires. And the accuracy rates of the knowledge,attitude and practice among the patient groups of different counties,genders,age groups,occupations and educational levels were analyzed. Results The accuracy rates of the knowledge,attitude and practice of patients on schistosomiasis control were 95.76%,82.80%,and 81.73% in Nanchang County;91.37%,93.32%,and 76.48%in Jinxian County;88.25%,67.56%,and 49.40%in Xinjian District. In the accuracy rates of knowledge,attitude and practice,the differences among the three counties (districts) were statistically significant (χ2=57.511-301.378,all P<0.05). Conclusions The accuracy rates of chronic schistosomiasis patients'attitude and prac-tice on schistosomiasis control in Nanchang City remain low. Therefore,the intensity of attitude and practice intervention should be strengthened in the Poyang Lake District in order to enhance the self-protection awareness of the patients.
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Objective To evaluate the role of new strategy in the transmission control of schistosomiasis in Poyang Lake re-gion. Methods The information and epidemic data of schistosomiasis control were collected and analyzed in Poyang Lake re-gion from 2005 to 2016. Results After eleven years of carrying out the new strategy,thirteen counties achieved the objective of transmission control in Poyang Lake region. In 2016,the number of schistosomiasis cases and human infection rate were 10301 and 0.03％,decreased by 89.64％and 99.45％compared with those in 2005,respectively. The number of cattle and schistosome-infected cattle were 68152 and 5,decreased by 50.84％and 99.83％compared with those in 2005,respectively. The average density of Oncomelania hupensis snails was decreased by 61.52％. No schistosome-infected snails were found since 2014. Con-clusion The new strategy accurately locates the key points and targets of schistosomiasis transmission chain ,which has con-trolled the human and animal's fecal eggs from polluting grassland,and cut off the transmission chain,reduced both the infec-tion rates of human and animal and the re-infection risk,and promoted to achieve the target of schistosomiasis transmission con-trol in Poyang Lake region.
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Objective To explore the technique of maximum entropy model for extracting Oncomelania hupensis snail habi?tats in Poyang Lake zone. Methods The information of snail habitats and related environment factors collected in Poyang Lake zone were integrated to set up the maximum entropy based species model and generate snail habitats distribution map. Two Land?sat 7 ETM+remote sensing images of both wet and drought seasons in Poyang Lake zone were obtained,where the two indices of modified normalized difference water index(MNDWI)and normalized difference vegetation index(NDVI)were applied to ex?tract snail habitats. The ROC curve,sensitivities and specificities were applied to assess their results. Furthermore,the impor?tance of the variables for snail habitats was analyzed by using Jackknife approach. Results The evaluation results showed that the area under receiver operating characteristic curve(AUC)of testing data by the remote sensing?based method was only 0.56, and the sensitivity and specificity were 0.23 and 0.89 respectively. Nevertheless,those indices above?mentioned of maximum en?tropy model were 0.876,0.89 and 0.74 respectively. The main concentration of snail habitats in Poyang Lake zone covered the northeast part of Yongxiu County,northwest of Yugan County,southwest of Poyang County and middle of Xinjian County,and the elevation was the most important environment variable affecting the distribution of snails,and the next was land surface tem?perature(LST). Conclusions The maximum entropy model is more reliable and accurate than the remote sensing?based meth?od for the sake of extracting snail habitats,which has certain guiding significance for the relevant departments to carry out mea?sures to prevent and control high?risk snail habitats.
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Objective To explore the impact of environment factors and social economic factors(environment interference factors for short)and control measures on the endemic status of schistosomiasis in Poyang Lake Eco?economic Region. Meth?ods The grey relational analysis model was applied to analyze the relationships between the key indexes of schistosomiasis epi?demic status and the environment interference factors and control measures in Jiujiang City of Poyang Lake Eco?economic Re?gion. Results Six environment factors,which included the annual average water level of Poyang Lake,average annual tempera?ture,storm frequency,annual average relative humidity,annual sunshine duration,and annual precipitation,had the most closed relationship with the indexes of schistosomiasis epidemic status(all ri>0.9). Among the socioeconomic factors,the num?ber of health technicians and beds of health facilities were most associated with the indexes of schistosomiasis epidemic status. Among the control measures of schistosomiasis,the number of cattle treated with extending chemotherapy,chemically killing of Oncomelania hupensis snails and eco?renovation were most associated with the indexes of schistosomiasis epidemic status. Con?clusion The various environment interference factors and their interaction should be considered in formulating the comprehen?sive control strategy for schistosomiasis,and the control strategy should be adjusted according to the epidemic dynamic and schistosomiasis?focused targets,so as to further strengthen the scientificity and validity of the control strategy.
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Objective To explore the immune mechanism of negative results of immune tests of schistosomiasis japonica pa?tients. Methods Totally 142 schistosomiasis patients(positive stool examinations)of Poyang Lake region were tested by ELI?SA method,and the ROC curve was applied to determine the high and low response of the patients. The levels of cellular immu?nity and cytokines of high and low responders were compared. Results Totally eight schistosomiasis patients were found as low responders. Besides SWAP?IgA(t= -1.588,P > 0.1),the levels of isotype antibodies were significantly lower in the low re?sponders compared with those in the high responders(t = -14.517 to -2.866,all P 0.05)compared with those in the high responders. The differences of IFN?γ and IL?10 between the high and low responders were both not significant(t= -2.426 to 0.216,all P >0.05). Conclusions There is a significant difference between the high and low responders only in the levels of isotype antibod?ies. One of the reasons of low response in the immune tests is the much lower antibody level after the antigen?antibody compound is completely formulated.
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Objective To evaluate the long?term effect of the comprehensive control strategy for schistosomiasis with empha?sis on infectious source control in marshland?type endemic areas of Poyang Lake. Methods Three heavy endemic villages with schistosomiasis in the lake areas were selected as pilots for the comprehensive control strategy which included replacing bovine with tractors and forbidding grazing on marshlands. The data of schistosome infections of residents and Oncomelania hupensis snails were collected and analyzed statistically from 2009 to 2014. Results There were no patients with schistosomiasis through feces examinations in the 3 pilot villages. The average density of live snails in Niuzhou marshland showed a decline trend and the density was stable in Liulingwei marshland. There were no infected snails in the 2 marshlands and no schistosome adult worms were found in the sentinel rats Conclusion The implantation of the comprehensive control strategy for schistosomiasis with em?phasis on infectious source control can control the prevalence of schistosomiasis during a long period.
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Objective To understand the dynamic of Oncomelania hupensis snail status in Duchang County at north shore of Poyang Lake so as to provide the evidence for formulating the strategy of schistosomiasis control. Methods The data about the snail status in Duchang County from 2005 to 2012 were collected and the change trend of the snail status was analyzed. Re?sults From 2005 to 2012 all the average density of living snails the occurrence rate of frames with living snails the density of infected snails and the area with infected snails showed a trend of sharp decline and stayed at a low level. Compared to 2005 the above 4 indexes in 2008 decreased by 70.06% 90.33% 79.48% and 37.88% respectively and those in 2012 decreased by 99.35% 98.98% 99.33% and 93.84% respectively. The infection rates of snails fluctuated between 0.06%and 0.53%which showed a trend of first decrease and then increase. The snail area maintained at the level of 2 052.5 hm2 since 2007. Con?clusions Most of the indexes of the snail status in Duchang County have decreased to the lowest level in history since 2012 but the snail area is stable and the infection rate of snails shows a fluctuation trend which suggests that the risks of schistosomia?sis transmission still exist and the snail control still should be strengthened.
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Schistosomiasis is closely related to natural environmental factors. The changes of environmental factors such as temperature hydrology vegetation soil etc. all impact the scope and extent of schistosomiasis transmission. Poyang Lake is the largest freshwater lake and one of the major endemic areas with schistosomiasis in China. With global warming the imple-mentation of the Three Gorges Dam operation and the Poyang Lake Ecological Economic Planning the natural environment in Poyang Lake area has been and will continue to change especially the water environment and climate environment which are more closely related to the schistosomiasis transmission. These changes to some extent have affected and will continue to affect the prevalence and transmission of schistosomiasis. This article reviews the relationship between the natural environment and its changes and schistosomiasis transmission in the Poyang Lake region.
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Objective To understand the characteristics of schistosome cercarial infested water contact of residents in Poyang Lake endemic areas after the operation of Three Gorges Project,so as to provide the evidence for formulating a well-directed con-trol strategy. Methods The residents in two villages in schistosomiasis endemic areas were selected and surveyed for their activi-ties of infested water contacts by questionnaire. Results The proportion and frequency of infested water contacts of residents in Poyang Lake region were high and the average rate of infested water contacts was 69.77%,and 98.96%of infested water contacts occurred in spring,summer and autumn. The main ways of infested water contacts were fishing/swimming/playing for adult men, washing clothes/fishing for adult women,and swimming/playing for school children,respectively. The rates of infested water con-tacts were 73.33%,71.63%and 61.87%in adult men,women and school children,respectively. The frequencies of infested water contacts>1 time/week,1 time/week-1 time/month,and<1 time/month were 62.61%,23.74%and 13.66%respectively. Conclu-sions The infested water contacts mainly occurs in spring,summer and autumn,and the main way of infested water contacts was fishing. Farming and mowing grass,which had been the primary way,now become the secondary way for the adult residents.
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Objective To explore the impact and change regularity of Oncomelania hupensis snails and vegetation in the marshlands of Poyang Lake caused by the impoundment of the Three Gorges Project. Methods By using the methods of stratified systematic sampling and pinpoint navigation,the succession of vegetation was observed and the distribution of O. hupensis snails was investigated in a period of 8 years on 4 typical marshlands in Poyang Lake. The regularity of changes in vegetation and O. hu-pensis snails was analyzed on the marshlands at high,medium and low elevations,respectively. Results After the impoundment of Three Gorges Project,the average flooding days of these 4 marshlands in 2004 and in 2008 were reduced of 74.8 and 65.8 days compared with those in 2002,the year just before the impoundment of the project,respectively. The change of spatial distribution pattern and the succession of dominant species of vegetation on the marshlands of Poyang Lake have taken place since 2005,and several vegetations showed a trend of moving toward the center of the lake. The hygrophilous vegetation has degenerated and gradu-ally been replaced by mesophily meadow in the marshland area above 14 m elevation. Carex,Phalaris arundinacea and Polygo-num appeared in large area and expanded slowly towards the center of the lake on the marshland below 14 m elevation. O. hupensis snails were mostly found under the Carex association. The tendency of decreasing in density of snails and of migration of snail habi-tats towards low terrain was observed. Conclusions The impoundment of Three Gorges Project has had a significant impact on hy-drological regimes,and a new succession of vegetation has taken place in the marshlands of Poyang Lake. O. hupensis snails and the mesophily vegetation show a trend of migrating slowly to the areas of low elevation in the marshlands.
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Objective To explore the relationship between the vegetation and space distribution of Oncomelania snails in Poyang Lake region,so as to get better understanding of the habitats of Oncomelania snails by using remote sensing technology.Methods The marshlands close to schistosomiasis endemic villages in Poyang Lake region were selected,and the traditional methods were used to investigate the situation of vegetation and Oncomelania snails.The longitude and latitude of investigation spots were recorded by GPS,and the field survey data were vectored by using ArcGIS software.The geometric calibration and unsupervised classification were made on TM satellite images of low-flow period of spring by using PCI 9.0.And then,the relationship between space distribution of snail habitats and vegetation was analyzed through superposing the filed data and satellite images.Results The vegetation in marshlands of Poyang Lake region can be differentiated as three types,in which the single dominant vegetation area was mainly breeding place of Oncomelania snails,and wet vegetation type and hybrid weed type were snail seldom breeding areas.Conclusions The distribution roles of vegetation in marshland are closely related to the habitats of snails,presenting a flaky and bandy distribution.The habitats of Oncomelania snails can be quickly understood by remote sensing technology.
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The endemic situation of schistosomiasis in Tangyin Village of Duchang County from 2000 to 2007 showed the infection rates of residents between 2003 and 2007 were all around 10%.In 2000.2002 and 2007,the infection rates of snails were 0.32%,O.45%and 0.38%,respectively,and the densities of infected snails were 0.016,0.004 No./0.1 m~2.and 0.004 No./0.1 m~2,respectively.It is suggested that the snail control and health education should be strengthened and the self-protection awareness of residents should improve for schistosomiasis control.
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Objective To observe the uhrasenographical characters of liver and spleen of residents and their changes in endearic areas of schistosomiasis japonica in Poyang Lake region.Jiangxi Province and to explore the value of ultrasonography for assessment of the morbidity of the disease.Methods All permanent residents aged above 3 years old were examined by ultrasonography and Kato-Katz method.Results The schistosome positive rates of fecal examinations decreased obviously from 16.29%in 1995 to 8.54%in 2007(P0.05),with the rates of 8.82% and 20.33% in 1995 and 8.54% and 21.34% in 2007,respectively.The abnormal rate of portal vein diameter decreased significantly.from 32.47%in 1995 to 6.50% in 2007.The abnormal rate of liver parenehyma increased remarkably(P<0.01),from 34.85% to 51.83%.The changes of liver parenchyma Grade I showed a bidirectional trend,29.90% of them chased into Grade 0(normal image on ultrasonngraphy),and 34.02% changed into Grade 2 and above.The abnormality of various indices of uhrasonography examinations were related to age,occupation and schistesome infection status.Conclusions Ultrasonography can show the damages of liver and spleen of patients infected with Schistosoma japonicum directly.but it is necessary to study further on the sensitive indices that reflecting early pathological changes and the best combination of the indices for the assessment of schistosomiasis-related morbidity.
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Objective To explore the epidemical pattern of acute schistosomiasis in Poyang Lake area so as to provide the scientific evidence for control-strategy-making. Methods The data of acute schistosomiasis in 12 counties along Poyang Lake from 1960 to 2007, including the data of 2 special investigations from 1982 to 1984 and from 1987 to 1989 were collected and analyzed with the retrospective investigation methods. Results There were 29 864 cases of acute schistosomiasis in 12 counties of Poyang Lake area from 1960 to 2007, accounting for 85.5% of the total acute schistosomiasis cases of Jiangxi Province. The largest number of cases existed in Yugan County, accounting for 18. 7%. The peak of acute schistosomiasis prevalence was in 1987 with 2 088 cases. However, the case of acute schistosomiasis declined significantly, keeping at a low level, since 1990. During the 2 special investigations, the people whose age were lower than 30 years old, were the susceptible populations of acute schistosomiasis (86. 1% and 82. 9% , respectively) , most of them were peasants and students, and the infection rates were 57. 4% and 21.2%, 61.7% and 21. 8%, respectively. Fishing and swimming were the main infection ways, with the infection rates of 43.0% and 44.9% , respectively. The peak season of infection was from April to October. Conclusions The river bank and continent of Poyang Lake are the main infection areas, the spring and autumn are the main epidemic seasons and the susceptible populations are the peasants, fishmen and young students. It is very important to enhance the comprehensive prevention and treatment measures in the key areas and population for schistosomiasis control.
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GPS was used in the snail survey of Nuanhuping marshland in Poyang Lake region and its application value was discussed. The results suggest that GPS which can measure the marshland area and survey area at real-time and draw electronic maps of snail situation rapidly, could realize the electronic and image management of the data from snail survey and provide more accurate information to the department in charge of schistosomiasis control.