Animals ; China ; epidemiology ; Humans ; Schistosomiasis ; epidemiology ; prevention & control

Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, and O. hupensis control is an important measure for schistosomiasis control. With the progress of national schistosomiasis control program, the prevalence of schistosomiasis is low in China; however, there are still multiple challenges for O. hupensis breeding and schistosomiasis transmission risk. Considering the target of the national schistosomiasis elimination program and environmental protection in the new era, the introduction of precision identification, precision interventions and precision assessment into O. hupensis control may facilitate the progress towards elimination of schistosomiasis in China.
Animals ; China/epidemiology* ; Schistosoma japonicum ; Schistosomiasis/prevention & control* ; Snails

OBJECTIVE: To analyze the distribution characteristics of emerging and reemerging Oncomelania hupensis snails after the criteria for transmission control of schistosomiasis were achieved in China, so as to provide insights into assessment of schistosomiasis transmission risk and formulation of snail control strategies during the elimination phase. METHODS: O. hupensis survey data in China from 2015 to 2021 were collected from the National Schistosomiasis Pevention and Control Information Management System, and the distribution characteristics of emerging and reemerging O. hupensis snails were descriptively analyzed. RESULTS: Emerging and reemerging O. hupensis snails were identified in China each year from 2015 to 2021, with relatively larger areas with emerging and reemerging O. hupensis snail habitats in 2016 and 2021, and relatively higher numbers of counties (districts) where emerging and reemerging O. hupensis snails were detected in 2016 and 2021. A total of 4 586.30 hm² of emerging O. hupensis snail habitats were found in 10 schistosomiasis-endemic provinces of China (except Fujian and Yunnan Provinces) from 2015 to 2021, with 96.80% in Anhui, Hunan and Hubei provinces, where marshland and lake endemic foci were predominant. A total of 21 023.90 hm² of reemerging O. hupensis snail habitats were found in 12 schistosomiasis-endemic provinces of China from 2015 to 2021, with 97.67% in six provinces of Hubei, Sichuan, Jiangxi, Jiangsu, Yunnan and Anhui, where marshland and lake and hilly endemic regions were predominant. Emerging snail habitats were found in 15.08% of all schistosomiasisendemic counties (districts) in China from 2015 to 2021, and 78.75% of all emerging snail habitats were identified in 11 schistosomiasis-endemic counties (districts), with the largest area of emerging snail habitats found in Lixian County, Hunan Province (645.00 hm²). Reemerging snail habitats were found in 47.67% of all schistosomiasis-endemic counties (districts) in China from 2015 to 2021, and 43.29% of all reemerging snail habitats were identified in 11 schistosomiasis-endemic counties (districts), with the largest area of reemerging snail habitats found in Weishan Li and Hui Autonomous County of Hunan Province (1 579.70 hm²). CONCLUSIONS Emerging and reemerging O. hupensis snails were identified in China each year from 2015 to 2021, with much larger areas of reemerging snail habitats than emerging snail habitats, and larger numbers of schistosomiasis-endemic provinces and counties (districts) with reemerging snails were found that those of provinces and counties (districts) with emerging snails. Specific snail control interventions are required tailored to the causes of emerging and reemerging snail habitats. Both emergence and reemergence of O. hupensis snails should be paid attention to in marshland and lake endemic areas, and Guangxi Zhuang Autonomous Region, Shanghai Municipality and Zhejiang Province where schistosomiasis had been eliminated, and reemergence of O. hupensis snails should be given a high priority in hilly areas. In addition, monitoring of O. hupensis snails should be reinforced in snail-free areas after flooding.
Humans ; China/epidemiology* ; Schistosomiasis/prevention & control* ; Cities ; Ecosystem ; Lakes

OBJECTIVE: To construct a schistosomiasis transmission risk assessment system in Wuhan City and preliminary evaluate its application effect, so as to promote the rational allocation of schistosomiasis control resources and accelerate the progress towards schistosomiasis elimination. METHODS: The schistosomiasis risk assessment indicators were collected through referring schistosomiasis surveillance data of Wuhan City from 2014 to 2020, literature review and expert interviews. Indicators within each criterion and sub-criterion were screened using the Delphi method, and a hierarchical structure model was created based on analytic hierarchy process. Quantitative assignment of each indicator was conducted according to relative importance, and the weight and combination weight of each criterion were calculated in each analytic hierarchy framework to create a schistosomiasis transmission risk assessment system, which was used for the schistosomiasis transmission risk assessment in 12 national schistosomiasis surveillance sites in Wuhan City. RESULTS: A three-level schistosomiasis transmission risk assessment system was preliminarily constructed, which included a target layer, 5 criterion layers and 21 sub-criterion layers. Of all indicators in the criterion layer, transmission route had the highest weight (0.433), followed by source of Schistosoma japonicum infection (0.294); and among all indicators in the sub-criterion layer, S. japonicum infection in Oncomelania hupensis and sentinel mice had the highest combination weight (0.125), followed by prevalence of S. japonicum infection in humans (0.091) and bovines (0.053), snail control by chemical treatment (0.049), positive rate of inquiry examinations (0.048), allocation of schistosomiasis control professionals (0.045), and areas of submerged snail-infested settings (0.041). Of the 12 national schistosomiasis surveillance sites in Wuhan City, there were 5 sites with weights of > 0.8, 4 sites with weights of 0.6 to 0.8, and 3 sites with weights of < 0.6 in 2020. CONCLUSIONS A schistosomiasis transmission risk assessment system has been constructed based on analytic hierarchy process in Wuhan City, which may provide a evidence-based basis for health resource allocation and decision-making for schistosomiasis control.
Animals ; Humans ; Cattle ; Mice ; Analytic Hierarchy Process ; Schistosomiasis/prevention & control* ; Schistosomiasis japonica/epidemiology* ; Snails ; Risk Assessment

OBJECTIVETo evaluate the practical value and the advantages of globe geographical positioning with wireless communication monitoring and supervision system in the field survey.

METHODSSpots which were randomly sampled by the National Ministry of Health for the investigation were chosen in the endemic areas for schistosomiasis in Jiangsu, Jiangxi, Anhui, Hunan, Hubei, Sichuan and Yunnan provinces. Portable GPS CEC9680 was used for collecting relevant waypoints and track, recording on-the-spot geographical positions. The positioning data package was sent back synchronously in the form of short message of SMS to the monitoring service center, and the moving routes of the terminal receiver monitored were displayed on the GIS map to achieve real-time supervision and staff scheduling.

RESULTSWith globe geographical positioning with wireless communication monitoring and supervision system, accurate positioning of 12 spots in the provinces of Jiangsu and 3 trial spots for schistosomiasis control with comprehensive treatment designated by the State Council has been established with real-time communicating recording, and monitoring systems.

CONCLUSIONThe globe geographical positioning with wireless communication monitoring and supervision system has provided a technical platform for the survey of schistosomiasis and other infectious diseases.

Animals ; China ; Environmental Monitoring ; methods ; Epidemiological Monitoring ; Geographic Information Systems ; Humans ; Schistosomiasis ; epidemiology ; prevention & control ; Schistosomiasis japonica ; prevention & control

OBJECTIVE: To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen. METHODS: The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years. RESULTS: A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% (χ² = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 (χ² = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline (Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05). CONCLUSIONS The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.
Animals ; China/epidemiology* ; Hemagglutination ; Humans ; Lakes ; Male ; Middle Aged ; Prevalence ; Schistosoma japonicum ; Schistosomiasis/epidemiology* ; Schistosomiasis japonica/prevention & control* ; Seroepidemiologic Studies

Animals ; China ; epidemiology ; Disease Outbreaks ; prevention & control ; Endemic Diseases ; prevention & control ; Feces ; parasitology ; Humans ; Schistosomiasis ; epidemiology ; prevention & control

OBJECTIVEUsing geographic information system (GIS) and the remote sensing techniques (RS), we developed a schistosomiasis database and geographic distribution map in Zhongxiang city,Hubei province in order to display and analyze the endemic situation longitudinally after the water conservancy project is completed.

METHODSEpidemiological data of schistosomiasis and the correlated climate and hydrology data for the last 30 years were collected and the relevant GIS databases were established under Artificial Neural Networks(ANN) and network training of Landsat TM images.

RESULTSGIS database of schistosomiasis in Zhongxiang city, Hubei province and its vicinity areas were developed including 1 maps regarding the epidemic situation of schistosomiasis. The areas of snail distributing were 4.4 hm2, 8.2 hm2, 24 hm2, 130.4 hm2, 8.13 hm2 and 7.53 hm2, respectively.

CONCLUSIONThe maps created by GIS database and RS techniques supported the complicated query on space and property, providing a new way in keeping,updating and analyzing available data. The techniques used should be able to provide evidence for the control of schistosomiasis to this water conservancy project.

Animals ; China ; epidemiology ; Climate ; Conservation of Natural Resources ; Databases, Factual ; Humans ; Schistosomiasis ; epidemiology ; prevention & control ; Snails ; Water

OBJECTIVETo understand the risk factors of schistosomiasis transmission in the Three Gorges Reservoir Area (TGRA) and to provide evidence for the development of control strategy.

METHODSApproaches including epidemiology, immunology and field survey were applied to investigate the potential risk factors which would involve the importation of infectious resources live mobile and migrant population, and livestock in the reservoir area. Meanwhile, observation on survival and reproductive status of snail under simulation habitats was also carried out, using ecological methods on snails. Strategy in preventing the spread of snail as infectious resources was also provided.

RESULTS175 mobile people from schistosomaisis endemic area of were tested and one person showed immunology tests positive with indirect hemagglutination test (IHA) and circumoral precipitin test (COPT), with a positive rate of 0.57%. Through the two-year period under observation, data showed that the snails with ribbon/smooth shells could survive and reproduce under habitats of simulation.

CONCLUSIONSOnce the infectious resource of schistosomiasis was introduced into the TGRA, the area became a new schistosomiasis epidemic area in TGRA which called for countermeasures to be taken.

Animals ; China ; epidemiology ; Disease Reservoirs ; Humans ; Risk Factors ; Schistosomiasis japonica ; epidemiology ; prevention & control ; transmission ; Snails ; parasitology

OBJECTIVETo use the snail survey data of Yugan, Jiangxi Province as an example to evaluate the effects and advantages of global positioning system integrated with digital maps and remote sensing data in order to manage and analyze the whole country's surveillance data of schistosomiasis by using geographic information system.

METHODSThe data of geographic information and snail information of 20 marshlands in Yugan, Jiangxi Province were collected, and by the correction of remote sensing images based on the digital maps and index extraction, the snail current situation and trend were analyzed and expressed.

RESULTSA series of specific procedure images of these 20 marshlands was established and the effects of Yugan surveillance platform based on geographic information system were validated.

CONCLUSIONThe whole country's surveillance data of schistosomiasis might be successfully integrated with geographic information system by global positioning system and be managed and expressed, which supplies a successful platform in using the surveillance data effectively.

Animals ; Environmental Monitoring ; Epidemiological Monitoring ; Geographic Information Systems ; Humans ; Schistosomiasis ; epidemiology ; prevention & control ; Snails ; Spacecraft