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A model was developed using remote sensing and geographic information system technologies for habitat identification of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum, in the Poyang Lake area, China. In a first step, two multi-temporal Landsat TM 5 satellite images, one from the wet and the second from the dry season, were visually classified into different land-use types. Next, the normalized difference vegetation index was extracted from the images and the tasseled-cap transformation was employed to derive the wetness feature. Our model predicted an estimated 709 km2 of the marshlands in Poyang Lake as potential habitats for O. hupensis. Near-ground temperature measurements in April and August yielded a range of 22.8-24.2 degrees C, and pH values of 6.0-8.5 were derived from existing records. Both climatic features represent suitable breeding conditions for the snails. Preliminary validation of the model at 10 sites around Poyang Lake revealed an excellent accuracy for predicting the presence of O. hupensis. We used the predicted snail habitats as centroids and established buffer zones around them. Villages with an overall prevalence of S. japonicum below 3% were located more than 1200m away from the centroids. Furthermore, a gradient of high-to-low prevalence was observed with increasing distance from the centroids. In conclusion, the model holds promise for identifying high risk areas of schistosomiasis japonica and may become an important tool for the ongoing national schistosomiasis control programme. The model is of particular relevance for schistosome-affected regions that lack accurate surveillance capabilities and are large enough to be detected at most commercially available remote sensing scales.

To analyze the progress of implementation of integrated strategy with emphasis on the control of infectious sources and effectiveness for joint-project of schistosomiasis control in Hubei province.Data on the endemic status and implementation of each integrated intervention in 6 collaborated counties including Gongan, Hanchuan, Honghu, Jiangling, Xiantao and Yangxin during 2009-2013 were collected and analyzed. 18 administrative villages with a history of endemic schistosomisis from 6 counties were selected for field survey. Individuals aged 6-65 years received screening test by IHA, and feces of antibody positive inhabitants were collected and tested by miracidia hatching technique. Hatching technique was conducted to determine the infection rate of schistosomiasis in cattle if there was any cattle existed.Various interventions were conducted with adaption to the local situation by the Departments of Agriculture, Water Conservancy, Forestry, and Health. The total number of cattle decreased from 75 388 at the beginning of 2009 to 1 805 at the end of 2013 in 6 counties with a reduction rate of 97.5%, while the prevalence in cattle reduced to 0-0.3% in 2013. Snail-infested areas were stable but areas with infected snails decreased significantly, and no infected snails were found in 2012-2013. Meanwhile, the infection rate of human beings on county level were less than 1%. No infected snails and cattle were found in 18 selected villages and the prevalence in inhabitants was in the range of 0-0.8%.Cooperation between provincial government and the Ministries of Health and Agruiculture accelerates the process to reach the criteria of transmission control of schistosomiasis in Hubei Province. However, sustainable effort in needed as the current endemic situation of schistosomiasis is stillunstable.

To establish the measures of schistosomiasis field survey and evaluate the efficacy of their application according to the content of indexes of rapid assessment system to high transmission risks in schistosomiasis endemic areas of lake regions.In 2012, based on the analysis of Oncomelania hupensis snail situation, and schistosomiasis epidemic data of human and cattle from 2008-2010, 60 villages from Hunan, Hubei, Jiangxi and Anhui provinces were selected and investigated, and the content of the investigation included the field feces, snail status, and epidemic situation of human and cattle. The systemic sampling was applied for snail investigation; the feces collected from snail investigation field were examined by the hatching test (3 bottles for 1 sample). A cluster random sampling was carried out with more than 300 people in each village. By using the hatching test (3 bottles for 1 sample) , the human stool examination was carried out for the identification of the infected persons who were positive in the immunity test screening. The hatching test was applied for cattle of all the villages (3 bottles for 1 sample).A total of 65 field feces spots were surveyed in 60 villages, field feces were found in 78.46% (51/65) of spots, and the positive rate of field feces was 1.07% (9/842). There were 73.33% (44,160)of villages with cattle, and the largest amount cattle with 329 was found in Wufeng Village, Jiangxi Province. The cattle infection rate was 1.5 1% (4,913,242) in 3242 investigated cattle. The highest cattle infection rate was 4% in Tongxin Village, Jiangxi Province. The population of 47 099 was surveyed, the infection rate was 0.77% (364/47 099), and the highest was 4.37% in Xumuchang Village, Hunan Province. The infection rate was 0 in 43.33% (26/60) of villages. No acute schistosomiasis cases were reported in all the villages in 2011 and 2012. Totally, 77 snail spots in 60 villages were investigated, and 51 spots were marshland and 26 spots were ditches. The schistosome-infected snails were detected in 5.88% (3/51 )of the marshland spots and the living snails were found in 80.39%(41/51) of the spots. The highest density of living snails was 3.20/0.1 m2 in Xumuchang Village, Hunan Province. The average density of infected snails was 0.00045/0.1 m2 (4/8942). The infected snail spots were distributed in Liujiadi Village and Liuhe Village of Hubei Province, and Jiangkou Village of Anhui Province. No infected snails were detected in 26 ditches spots. The living snails were detected in 53.85% (14/26) of the ditches spots. The highest average density of living snails was 3.76/0.1 m2 in Huakou Village, Hubei Province.The measures of field survey for rapid assessment system of high transmission risks in schistosomiasis endemic areas of lake regions are established and applied with scientific, impersonal and rapid characteristics.

To assess the impact of the "4 x 20" Lushan Earthquake on the risk of schistosomiasis transmission in Lushan and Tianquan counties, so as to provide the evidence for formulating appropriate measures for schistosomiasis prevention and control.Based on a comprehensive literature review, an analysis of schistosomiasis monitoring data in the earthquake affected counties, and a field investigation, a rapid assessment on the impact of the earthquake on schistosomiasis was conducted.Lushan and Tianquan counties were two endemic areas of schistosomiasis with high transmission level in history, especially Lushan County where Oncomelania snail distribution/density was the highest in Sichuan Province. After the earthquake, the streams and damaged ditches were blocked up, potentially leading to the spread of Oncomelania snails, and the damaged sanitary facilities may also lead to the release of excrement, contaminating the environment where snails resided. Meanwhile, the people who were relocated due to the earthquake may have higher exposures to contaminated environment. In addition, increasing population mobility (e.g. relief workers) also had the potential to bring infection sources in the earthquake affected areas. Further, animals, which may serve as reservoirs for the parasite such as homeless dogs, may also add the complexity of local schistosomiasis transmission.The epidemic risk of schistosomiasis in Lushan and Tianquan counties is high. To prevent the outbreak and epidemic of schistosomiasis, the victim settlements should be established appropriately and the excrement should be managed carefully. Meanwhile, the snail control should be carried out in the high-risk environments. The health education, monitoring, patient treatments and expanded chemotherapy should be carried out and strengthened.

To establish an index system for rapid assessment of environment with high transmission risk of schistosomiasis in marshland and lake regions.The alternative indices were established preliminarily by the documentary method, and then the Delphi method was used two rounds to select the indices and establish the index system. The degree of familiar and authority of the experts as well as the weights of all indices were assessed.A total of 3 primary indices namely morbidity in domestic animals, morbidity in humans and Oncomelania snail status were established, among which the weight of morbidity in domestic animals (0.68) was the highest. Totally 16 secondary indices were established, among which the combinative weights of the positive rate of wild feces (0.09), the infection rate of livestock (0.09), the infection rate of humans (0.07), the number of cases with acute schistosomiasis (0.07), the area with infected snails (0.07), and the density of infected snails (0.07) were the highest. The coefficients of familiar degree and authority degree of the experts of the primary indices were 0.79-0.85 and 0.88-0.91, and those of the secondary indices were 0.68-0.86 and 0.77-0.91, respectively.The index system for rapid assessment of environment with high transmission risk of schistosomiasis in marshland and lake regions is established preliminarily. Using this system, we can assess the key endemic indices of humans, domestic animals and snails to understand the endemic situation in the investigated sites.

To investigate and analyze the schistosomiasis endemic status and influencing factors in areas of schistosomiasis transmission control in hilly regions of mountain areas, so as to provide the reference for establishing the strategy and measures to achieve the target of schistosomiasis transmission-interrupted in the similar areas.Dongpo District of Meishan City, Sichuan Province, which was appropriate to the standards of schistosomiasis transmission controlled by national evaluation in 2008, was selected as a study area. The data of schistosomiasis control from 2008 to 2010 were collected. A survey for epidemiological factors was carried out from April to November in 2011. The survey of Oncomelania snails was performed with the systematic sampling combined with environmental method. The schistosome infection status of residents was investigated by the seroimmunological test and fecal hatching examination. The schistosome infection status of cattle was investigated by the plastic cup with top tube hatching method. The infested water contact of residents was investigated with questionnaire. At the same time, in 2011, a simple random sampling combined with rapid field assessment method was used to investigate the distribution of outdoor feces, outdoor feces containing schistosome eggs, snails and infected snails in two spots of Jingyang District, Deyang City and Renshou County, Meishan City which had been appropriate to the standards of schistosomiasis transmission controlled in 2006 and 2007 respectively.From 2008 to 2010, 182.6 thousand-213.3 thousand local residents were examined in Dongpo District, the positive rate of sero-immunological tests of population was 6.30% - 6.81%, and the infection rate of population was 0.02% -0.07% by estimated calculation. Totally 2 835-7 260 heads of cattle were examined and no positive cases were found. The areas of snail habits were 190.00-232.00 hm2, the intensities of living snails were 0.02-0.19 snails/0.1 m2, and no infected snails were found. In 2011, totally 204.4 thousand residents were examined and the positive rate of sero-immunological tests of population was 4.98% but no positive cases were founded through the parasitological tests. A total of 1 735 heads of cattle were examined and no positive cases were found. The areas of snail habits were 99.00 hm2, the intensity of living snails was 0.18 snails/ 0.1 m2, and no infected snails were found. Questionnaire analyses of a total of 537 residents in 4 villages showed that ditch, channel, pond, and paddy field were the major environments of the infested water contact of the residents. In the ditches and paddy fields, the average annual median values of water contact of residents were 15 and 20 person-times respectively before the area was appropriate to the standards of schistosomiasis transmission controlled, and 20 and 30 person-times respectively after the area was appropriate to the standards of schistosomiasis transmission controlled, and there were no significant differences (chi(ditch2) = 1.61, chi(padd field2) = 0.03, both P0.05). Whereas, in the channels and ponds, the average annual median values of water contact were 15 and 30 person-times respectively before the area was appropriate to the standards of schistosomiasis transmission controlled, but they were significantly reduced after the area was appropriate to the standards of schistosomiasis transmission controlled (chi(channel2) =10.35, chi(pond2) =18.69, both P0.01). In 2011, the rapid field investigation and assessment showed that the average appearance rates of snails through screening were 60.15% and 12.12% respectively in the 2 villages. The average densities of living snails were 1.19 snails/0.1m2 and 0.20 snails/0.1m2 respectively in the 2 villages, and there were no infected snails. A total of 78 outdoor feces of cattle and sheep were collected and the fecal hatching examinations showed that there were no positives.After the schistosomiasis endemic areas in hilly regions of mountain areas are appropriate to the standards of schistosomiasis transmission controll, the achievements have been consolidated. However, the potential schistosomiasis endemic factors still exist, such as the high positive rate of schistosome sero-immunological tests in population, frequently bovine flowing, and no obviously decrease of the snail area and density of living snails. Therefore, it is an urgent need to develop more suitable new technologies and measures to accelerate the process of schistosomiasis prevention and control.

To observe the toxicity of niclosamide with plastic film mulching to fish.A ditch with Oncomelania snails was selected as the study site, and it was divided into a control group and a molluscicide group. After the river closure, the molluscicidal group was sprayed with niclosamide with a dosage of 2 g/m2, and then covered with plastic film; no molluscicide measure was implemented in the control group. The toxicity of the molluscicide to carp fish in resting and flowing water environment was observed.In flowing water, the death rates of carp fry of the molluscicidal and control groups showed no statistical difference 7 d after the film mulching (P = 0. 680), and no carp fry died in the 2 groups after plastic film taking off for 4 d. The death rates of carp fry between the 3 sites (with a distance of 50, 100 and 150 m from the molluscicidal group, respectively) and the control group had no statistical difference 7 d after film mulching (P = 0.955), and no dead fry was discovered 4 d after taking off the film. In downstream, for the death rates of carp fry, there was no difference between the molluscicidal group and the control group (P = 0.376). The death rates of snails before and after the molluscicidal experiment showed a significant difference (P0.01).The technology of niclosamide molluscicide with plastic film mulching can not only improve the molluscicidal effect, but also avoid the toxicity to fish, which is suitable for special environment such as a fish pond.

To evaluate the molluscicidal effect of film on ditches in mountainous schistosomiasis endemic regions.A ditch with Oncomelania hupensis snails was selected as experimental field. The ditch was divided into 3 parts (groups): a niclosamide plus film covering group (film covering after spraying by wettable powder of 50% niclosamide ethanolamine salt upon 2 g/m2), a film covering group (film covering directly without niclosamide spraying), and a control group (no molluscicidal measures). The snail investigation was performed 7, 10, 40, 60 d and 90 d after film covering. The temperatures outside and inside film were determined twice a day during the experiment.The temperature inside the film was significantly higher than that outside the film (t = 4.12, P0.01). Compared with the densities of living snails before the experiment, the densities of living snails decreased by 99. 01% and 67.71% seven days post-film in the niclosamide plus film covering group and film covering group respectively; 96.58% and 93.06% ten days post-film respectively; both 100% forty days post-film. The multi-factor regression model indicated that covering film with niclosamide applying, extending film covering time, and increasing cumulate temperature inside film could enhance the molluscicidal effect.The film covering has well molluscicidal effect. The molluscicidal effect of covering film with niclosamide is better than that of covering film alone in short time. However, the covering film alone also has good molluscicidal effect when increasing covering time.

To analyze factors affecting transmission of schistosomiasis japonica in Poyang Lake.Successive surveillance data for at least three years from 1992 to 1998 at the schistosomiasis endemic administrative villages surrounding Poyang Lake were collected, including the egg positive rate by stool examination, investment on treatment of patients and mollusciciding in snail habitat, risk areas, bovine infection rate. Data on rainfall and temperature were also obtained from the relevant agencies. Step-wised regression method was employed to analyze the data.The regression model established is statistically significant, R2 equals 0.735, P0.01. The accepted variables affecting the transmission of the disease were natural logarithm of human infection rate in last year, risk areas, infection rate of bovine, investment values of niclosamide per risk area and value of praziquantel administered per infection rate.Chemotherapy and mollusciciding effectively reduced schistosomiasis transmission in Poyang lake region, while the infection rate, risk areas, bovine infection rate still drive the transmission.