Association between the ß-blocker use and patients with sepsis: a cohort study.

Objective: This study aimed to assess whether ß-blockers are associated with mortality in patients with sepsis. Method: We conducted a retrospective cohort study of patients with sepsis using the Medical Information Market for Intensive Care (MIMIC)-IV and the emergency intensive care unit (eICU) databases. The primary outcome was the in-hospital mortality rate. The propensity score matching (PSM) method was adopted to reduce confounder bias. Subgroup and sensitivity analyses were performed to test the stability of the conclusions. Results: We included a total of 61,751 patients with sepsis, with an overall in-hospital mortality rate of 15.3% in MIMIC-IV and 13.6% in eICU. The inverse probability-weighting model showed that in-hospital mortality was significantly lower in the ß-blockers group than in the non-ß-blockers group [HR = 0.71, 95% CI: 0.66-0.75, p < 0.001 in MIMIC-IV, and HR = 0.48, 95% CI: 0.45-0.52, p < 0.001 in eICU]. In subgroups grouped according to sex, age, heart rate, APSIII, septic shock, and admission years, the results did not change. Conclusion: ß-blocker use is associated with lower in-hospital mortality in patients with sepsis, further randomized trials are required to confirm this association.

The Current Distribution of Oncomelania hupensis Snails in the People's Republic of China Based on a Nationwide Survey.

Schistosomiasis is a helminth infection caused by the genus Schistosoma, which is still a threat in tropical and sub-tropical areas. In the China, schistosomiasis caused by Schistosoma japonicum is mainly endemic to the Yangtze River valley. The amphibious snail Oncomelania hupensis (O. hupensis) is the unique intermediate host of S. japonicum; hence, snail control is a crucial approach in the process of schistosomiasis transmission control and elimination. In 2016, a nationwide snail survey was conducted involving all snail habitats recorded since 1950 in all endemic counties of 12 provinces. A total of 53,254 existing snail habitats (ESHs) were identified, presenting three clusters in Sichuan Basin, Dongting Lake, and Poyang Lake. The overall habitat area was 5.24 billion m2, of which 3.58 billion m2 were inhabited by O. hupensis. The area inhabited by snails (AIS) in Dongting and Poyang Lakes accounted for 76.53% of the population in the country. Three typical landscape types (marshland and lakes, mountains and hills, and plain water networks) existed in endemic areas, and marshland and lakes had a predominant share (3.38 billion m2) of the AIS. Among the 12 endemic provinces, Hunan had a share of nearly 50% of AIS, whereas Guangdong had no ESH. Ditches, dryland, paddy fields, marshland, and ponds are common habitat types of the ESH. Although the AIS of the marshland type accounted for 87.22% of the population in the whole country, ditches were the most common type (35,025 or 65.77%) of habitat. Six categories of vegetation for ESHs were identified. A total of 39,139 habitats were covered with weeds, accounting for 55.26% of the coverage of the area. Multiple vegetation types of snail habitats appeared in the 11 provinces, but one or two of these were mainly dominant. Systematic sampling showed that the presence of living snails was 17.88% among the 13.5 million sampling frames. The occurrence varied significantly by landscape, environment, and vegetation type. The median density of living snails in habitats was 0.50 per frame (0.33 m × 0.33 m), and the highest density was 40.01 per frame. Furthermore, two main clusters with high snail densities and spatial correlations indicated by hotspot analysis were identified: one in Hunan and Hubei, the other in Sichuan. This national survey is the first full-scale census on the distribution of O. hupensis, which is significant, as transmission interruption and elimination are truly becoming the immediate goal of schistosomiasis control in China. The study discerns the detailed geographic distribution of O. hupensis with the hotspots of snail density in China. It is beneficial to understand the status of the snail population in order to finally formulate further national control planning.

Rapid Assessment on Potential Risks of Schistosomiasis Transmission - 7 PLADs, China, 2019 and 2021.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Oncomelania hupensis(O. hupensis) and livestock are main infection sources of schistosomiasis. The schistosome infected O. hupensis and livestock's feces are important risk factors in the transmission of schistosomiasis. WHAT IS ADDED BY THIS REPORT?: The potential risks of schistosomiasis transmission remain prevalent, giving an early warning to local government with information on existing transmission risks. It is expected that the effectiveness and efficiency of schistosomiasis surveillance could be improved by conducting rapid risk assessment at the beginning of transmission season. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: Rapid risk assessment is essential in early detection and the active monitoring of indicators of the transmission risks of schistosomiasis in endemic areas. This could work synergistically with surveillance system to minimize infections and prevent rebounds of endemic schistosomiasis outbreaks.

Synthesis of SDS-Modified Pt/Ti3C2Tx Nanocomposite Catalysts and Electrochemical Performance for Ethanol Oxidation.

It is well-known that platinum (Pt) is still the preferred material of anode catalyst in ethanol oxidation, however, the prohibitive high cost and CO poisoning of Pt metal impede the commercialization of fuel cells. Therefore, improving the utilization rate of catalysts and reduce the cost of catalyst become one of the most concerned focus in the construction of fuel cells. In this work, the Pt-based catalysts are synthesized by using different content of sodium dodecyl sulfate (SDS) modified-Ti3C2Tx support, and the dispersion regulation function of SDS modified-Ti3C2Tx supported on Pt nanoparticles is investigated. The structure, composition and morphology of different catalysts are characterized by X-ray diffraction (XRD), X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution TEM, respectively. It is found that the Pt nanoparticles in pure Ti3C2Tx surface are serious aggregated and show poor dispersion, whereas the Pt nanoparticles in SDS modified-Ti3C2Tx have a better dispersion. The electrochemical results revealed that SDS modified-Ti3C2Tx supported Pt nanoparticles has higher electrocatalytic activity and stability in both acidic and alkaline ethanol oxidation when the dosage of SDS increases to 100 mg. These findings indicate that the SDS-Ti3C2Tx/Pt catalysts show a promising future of potential applications in fuel cells with modification of Ti3C2Tx support.

Schistosomiasis in a migrating population in the lake region of China and its potential impact on control operation.

Coverage of migrating people in schistosomiasis control program is a growing concern in China. Schistosomiasis caused by Schistosoma japonicum is still one of the major infectious diseases of public health importance in China though tremendous efforts have been made to control the transmission over the past decades. Along with the rapid social-economic development, migrant population has been remarkably increasing across the country. The infected migrants may introduce a new souse of infection to endemic areas or the areas where the transmission had been controlled or interrupted but the intermediate host Oncomelania snail is still present. Preliminary studies for surveillance on schistosomiasis prevalence in migrants were reported, but there is little basic information provided. We carried out an investigation on the prevalence in immigrants, emigrants and permanent residents in three villages of Hunan province located in the main endemic area of lake region, and analyzed the potential impact of migration on control practice. In the study villages, the migrant population accounts for 53.6% of the total. Schistosoma infection was detected by modified Kato-Katz method and miracidium hatching test. Questionnaire survey was conducted comprising knowledge of disease and its transmission, water contact, personal protective measures, and whether examined and treated after water contact. The survey indicated that the migrants and permanent residents had similar life style, and the majority of them experienced water contact in agricultural work or routine life activities. However, the infection rate in immigrants was significantly higher than that in permanent residents. It was also found that the migrants had significantly less knowledge about the disease than the permanent residents, and took no personal protective measures. This is due to that the control program could not cover the migrants when they were absent at the time the program being implemented. The present study suggested that the surveillance and intervention for migrants, immigrants in particular, should be included and strengthened in schistosomiasis control program and a feasible scheme be developed.

[Assessment on the effect of joint effort for schistosomiasis control in Hubei Province].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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%. CONCLUSION: 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.

Comparison of the miracidium hatching test and modified Kato-Katz method for detecting Schistosoma japonicum in low prevalence areas of China.

The diagnosis of Schistosoma japonicum (Sj) infection in low prevalence areas of the People's Republic of China is challenging due to the sensitivity of the detection methods, leading to an underestimation of the disease burden. We compared the sensitivities of the miracidium hatching test (MHT) with the modified Kato-Katz method (KK) and the combination of the two methods (KK-MHT) to detect Sj infection in low prevalence areas of China. The stool samples of 3,853 residents from 8 villages with a light to moderate prevalence (0-23%) of Sj infection were examined by KK, MHT and KK-MHT. The findings were inconsistent. The KK-MHT conbination gave more positives than either the KK or MHT alone. Using the KK-MHT, we determined the missed rates with the KK (mR(K)) and MHT (mR(H)) to be 30.1% and 10.2%, respectively. At light prevalence sites (infection rate < 10%) the mR(K) was 60.6%, significantly higher than the mR(K) of 22.3% found at moderate prevalence sites (10-23%). However, the mR(H) at the light and moderate prevalence sites were 11.54% and 9.90%, respectively (p > 0.05). The combination KK-MHT had the best sensitivity in low Sj prevalence areas in China and the KK method alone was the least sensitive. Using KK alone as a screening method will result in an underestimation of Sj infection disease burden.

[Schistosomiasis control effect of measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions].

OBJECTIVE: To evaluate the schistosomiasis control effect of the measures of replacing cattle with machine for cultivation and forbidding depasturage of livestock on marshlands in marshland and lake regions. METHODS: The retrospective review 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 human, cattle, and Oncomelania hupensis snails, and schistosome-infested field excreta were surveyed from 2007 to 2013. The effects 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 implemented 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, P < 0.05), with the descend range of 82.53%. The descend ranges of the measures of replacing cattle with machine for cultivation and forbidding the depasturage of livestock on marshlands were 83.081% and 81.62% respectively, and there was no significant difference between the two measures (χ2 = 0.132, P > 0.05). 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 significantly 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.

[Establishment and application of rapid assessment system of environment with high transmission risk of schistosomiasis in marshland and lake regions. I. Establishment of an index system with Delphi method].

OBJECTIVE: To establish an index system for rapid assessment of environment with high transmission risk of schistosomiasis in marshland and lake regions. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Establishment and application of rapid assessment system of environment with high transmission risk of schistosomiasis in marshland and lake regions II establishment and application of measures for field survey].

OBJECTIVE: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

[Evaluation of the comprehensive schistosomiasis control measures with emphasis on infection source of replacing cattle with machine].

OBJECTIVE: To evaluate the effect of comprehensive measures with an emphasis on schistosomiasis infection source control by replacing cattle with machine. METHODS: In 2011, 2 villages from each of Jingzhou District, Jianli County and Jiangling County, Hubei Province, were selected as intervention group where the comprehensive measures were implemented, while 2 villages from Shishou City served as control with routine control activities. A cluster random sampling was carried out in the 8 villages with more than 300 people in each village were sampled. Stool examination using modified Kato-Katz was applied for identification of the infected persons and hatching test for cattle survey. The systemic sampling was applied for snail survey, fecal specimens from the field were examined by hatching test. Each sample was examined three times. Data were collected for the analysis of control effect between intervention and control groups in 2007 (baseline), 2009 (before implementation of comprehensive measures) and 2011 (post-intervention). RESULTS: In intervention villages, the overall prevalence in human reduced significantly from 3.6% (135/3 772) in 2007 and 2.0% (63/3 116) in 2009 to 0.9% (21/2 396) in 2011 (chi2 = 43.411, chi2 = 11.840, P < 0.05). Until 2011, there were no cattle in intervention group; the prevalence decreased by 52.6% in human and about 100% in cattle from 2010 to 2011. In control group, the infection rate in residents in 2007, 2009 and 2011 was 4.5% (64/1 410), 2.6% (34/1 294) and 1.8% (24/1,320), respectively (chi2 = 16.178, P < 0.05), and 5.1% (8/158) in 2007, 1.6% (3/187) in 2009 and 1.6% (3/189) in 2011 in cattle, respectively (chi2 = 3.387, P > 0.05). The infection rate in human and cattle fell by 25.0% and 5.9% from 2010 to 2011, respectively. There was a significant difference in human infection rate between the intervention and control groups after intervention (chi2 = 6.309, P < 0.05). No infected snails were detected in intervention and control groups. No positive feces from the field was found in the intervention group, 7.5% positive rate was recorded in the control. CONCLUSION: The comprehensive measures focused on infection source control by replacing cattle with machine can effectively control Schistosoma japonicum transmission, with a significant decrease of the prevalence in human and cattle.

[Cost-effectiveness evaluation and investigation of control measure changes in areas of schistosomiasis transmission control in hilly regions of mountain areas I epidemiological investigation and analysis of prevalence factors of schistosomiasis].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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 P > 0.05). 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 P < 0.01). 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. CONCLUSIONS: 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.

[Effect of niclosamide spreading oil on killing schistosome cercariae].

Dechlorinated water (100 ml, 30 degrees C) was put into a plate (diameter 15 cm), and 1% niclosamide spreading oil 5 microl was added, then a ring of Schistosoma japonicum cercariae were picked up to the plate. The time of killing all the cercariae was observed at three time points (immediately, 24, 48 h), and the dechlorinated water was used as control. The results showed that schistosome cercariae were all killed in three minutes by 1% niclosamide spreading oil at the three time points. The cercaria-killing effects of each time point were not significantly different (F = 0.062, P > 0.05). The cercariae were alive in the control in 48 h.

[Indirect hemagglutination test capabilities of personnel from institutes of schistosomiasis control at basic levels in lake areas].

OBJECTIVE: To understand the indirect hemagglutination test capabilities of personnel from the institutes of schistosomiasis control at the basic levels in lake areas. METHODS: All the contestants were grouped by the operation standard, qualitative judgment, quantitative determination, and geographical location of Hunan and Hubei provinces, and their scores were statistically analyzed by SPSS 16.0 software. RESULTS: The total scores of the contestants of the two provinces were high and there was no significant difference between them. Among the professional persons, the scores of operation standard and qualitative judgment were significantly higher than those of quantitative determination. There were no significant differences among the scores grouped by the different genders, ages, professional titles and areas (all P > 0.05). CONCLUSIONS: The quantitative determination of indirect hemagglutination test of personnel from the institutes of schistosomiasis control at the basic levels is not very good. Therefore, the training of test capacity still should be strengthened.

[Evaluation on molluscicidal effect of suspension concentrate of metaldehyde and niclosamide].

OBJECTIVE: To evaluate the molluscicidal effect of suspension concentrate of 26% metaldehyde and niclosamide (MNSC) in laboratory and field. METHODS: The experiment of MNSC against Oncomelania snails were performed by immersion and spray methods with different time in laboratory and field, and the wettable powder of 50% niclosamide ethanolamine salt (WPN) and fresh water were set as the controls. RESULTS: In laboratory, by immersion method (immersion for 24 h), LC50 of MNSC was 0.058 3 mg/L, which was lower than 0.094 7 mg/L of WPN. For the concentrations of 2.0 mg/L and 1.0 mg/L of MNSC by immersion method (immersion for 24, 48 h and 72 h, respectively), the death rates of snails were all 100%. In laboratory, by the spray method, the snail death rates were higher than 97% on the 3rd and 7th day when the dosage of MNSC was higher than 1.0 g/m2. In the field, by the immersion method, the snail death rates of MNSC (2 g/m3) for 24, 48 h and 72 h were 97.78% -100% in Hubei Province and 97.50% - 100% in Anhui Province, respectively, the rates of WPN were 98.89% - 100% and 97.56% - 100%, respectively, and the snail death rates of MNSC and WPN were both 100% in Jiangsu Province. In the field, by the spray method, the snail death rates of MNSC for 1, 3 d and 7 d were 83.12% - 94.64% in Jiangsu Province, 67.81% - 86.67% in Hubei Province and 72.80% - 100% in Anhui Province, respectively. The snail death rates of WPN for 1, 3 d and 7 d were 78.40% - 86.11%, 77.27% - 87.50% and 83.81% - 98.51%, respectively. In Hunan Province, the snail death rates of MNSC and WPN after spraying for 7 d were 94.94% and 94.20%, respectively, after spraying for 15 d, the rates were 86.67% and 89.38%, respectively. CONCLUSIONS: The molluscicidal effect of MNSC is as the same as WPN by immersion and spray methods in laboratory and field. MNSC has the characteristics of good water solubility, quick dispersing and easy using. In addition, the efficiency component of MNSC is half of WPN. So MNSC is a novel form of molluscicide which is worthy of promotion in field.

[Toxicity of niclosamide with plastic film mulching to fish].

OBJECTIVE: To observe the toxicity of niclosamide with plastic film mulching to fish. METHODS: 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. RESULTS: 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 (P < 0.01). CONCLUSIONS: 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.

[Molluscicidal effect of film on ditches in mountainous schistosomiasis endemic regions].

OBJECTIVE: To evaluate the molluscicidal effect of film on ditches in mountainous schistosomiasis endemic regions. METHODS: 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. RESULTS: The temperature inside the film was significantly higher than that outside the film (t = 4.12, P < 0.01). 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. CONCLUSIONS: 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.

[Investigation on migration regularity and schistosome infection of migrant population in mountainous regions].

OBJECTIVE: To understand the migration regulation, knowledge of schistosomiasis control and infection status of migrant population in mountainous regions. METHOD: Migrants from history heavy endemic villages of schistosomiasis were selected by the convenience sampling method, then they were investigated by questionnaire and fecal examination. RESULTS: A total of 884 migrants were investigated, the infection rate was 2.49%, and the awareness rate of knowledge on schistosomiasis control was 43.94%. Most of the migrant places were in schistosomiasis endemic areas, and those who accepted the examination and treatment of schistosomiasis accounted for a low percentage. The compliance rate of schistosomiasis examinations and treatment of migrant population was low. The general time of returning hometown was around the Chinese Spring Festival. CONCLUSION: As one of the key population of schistosomiasis control, the control work on migrants should be strengthened.

[Compliance of film-coated praziquantel tablets in schistosomiasis transmission-controlled areas].

OBJECTIVE: To observe the compliance of film-coated praziquantel tablets in the schistosomiasis transmission controlled areas, so as to provide the evidence for the establishment of chemotherapy intervention measures in these areas. METHODS: In the areas of schistosomiasis transmission controlled in Sichuan Province, 234 people were selected as film-coated praziquantel group (FCPG), and 203 people were selected as praziquantel group (PG). A questionnaire survey was implemented and the compliance of chemotherapy of the 2 groups was compared. RESULTS: In PG, all the people indicated that the praziquantel tablets has bad smell, 98.0% of the people had side-effects, such as nausea, headache, 69.5% thought the medicine was harmful to health subjectively, and 99.5% thought that it was too much dose of tablets for taking one time. In FCPG, all the people indicated that the film-coated praziquantel tablets had no bad smell, 18.8% of the people had side-effects, and 74.4% would like to choose film-coated praziquantel tablets. The rates of knowledge of praziquantel of PG and FCPG were 50.7% and 29.1%, respectively ( chi2 = 21.449, P = 0.01). CONCLUSIONS: The film-coated praziquantel tablets have no bad smell and lighter side-effects. The compliance of the film-coated praziquantel tablets is high in the areas of schistosomiasis transmission controlled, so the film-coated praziquantel tablets are worth to popularize and apply.

[The effect and influencing factors of schistosomiasis control by forbidding livestock denaturing on marshland with Oncomelania snails].

OBJECTIVE: To evaluate the effect of schistosomiasis control by forbidding livestock denaturing on marshland with Oncomelania snails and to analyse its influencing factors. METHODS: The village of Aiguo, Xinhe, Huangjia, Fanrong, Fengfu and Caomen and its respective nearby marshland, i.e., Aiguoniu, Liulingwei, Huangjianiu, Da, Goulian, and Litouzui, in Jinxian county, Jiangxi province were selected as the pilot areas for implementing the measures of forbidding livestock denaturing on the marshlands with Oncomelania snails during the period of the year 2005 to 2007. A total of 300 residents in each village were randomly chosen for stool examination with the Kato-Katz technique every year. The snail survey was carried out in spring and autumn every year on the marshlands close to the villages with systemic sampling method. The marshlands with a height 16.5 m above the sea level in Futian was selected for snail survey and planting with sesame. The residents aged 20 - 50 years old in Fengfu and Aiguo villages were studied by using questionnaire on the compliance of forbidding livestock pasturing on marshlands with Oncomelania snails. RESULTS: Before implementation of the measures, human infection rate with Schistosoma japonicum was 11.35% (90/793) in Aiguo, 4.00% (12/300) in Xinhe, 4.00% (6/150) in Huangjia, 8.00% (12/150) in Fanrong, 3.17% (4/126) in Fengfu and 6.64% (14/211) in Caomen. After implementation in 2008, human schistsome infection rate in the aforementioned 6 villages was declined to 0.18% (1/551), 0.00% (0/348), 0.00% (0/316), 2.27% (7/308), 1.17% (5/428) and 1.16% (5/430), respectively. Only in Fengfu village the decline of the human prevalence was not significant (χ(2) = 2.4, P = 0.12), while in the other 5 villages, human prevalence rate had been declined significantly (χ(2) = 126.77, P < 0.01; χ(2) = 16.31, P < 0.01; χ(2) = 18.79, P < 0.01; χ(2) = 10.39, P < 0.01; χ(2) = 14.17, P < 0.01, respectively). Infected snails were not found in 5 out of the 6 marshlands close to the villages. Three infected snails were founded in Da marshland because of poor environmental isolation. Before planting, the living snail density was 0.063/0.11 m(2) (34/540), and after planting, the living snail density was 0.0074/0.11 m(2) (4/538), a 88.25% reduction (Z = 12.47, P < 0.01) was recorded through economy crop planting at Futiandaan marshland in 2008. A total of 986 pieces of questionnaire were provided, and 968 valid ones were collected. The results of questionnaire indicate that compliance of forbidding livestock denaturing on marshland with Oncomelania snails in Aiguo and Fengfu villages was 84.38% (216/256) and 75.42% (537/712), respectively. Using logistic regression model, knowledge level on harmfulness of livestock denaturing on marshland with Oncomelania snails, willingness of culture with machine to substitute traditional cattle culture, and willingness of investment to marshland culture development are 3 varieties that affect residents' implementation of forbidding livestock denaturing on marshland with Oncomelania snails. CONCLUSION: The infected snail density and human schistosome infection rate were reduced on the marshlands of well environmental isolation after 2 - 3 years implementation of forbidding livestock denaturing on marshlands with Oncomelania snails. The key influencing factors of forbidding livestock denaturing on marshland with Oncomelania snails are knowledge level on harmfulness of livestock denaturing on the snail infested marshlands, the willingness of machine culture to substitute cattle culture, and the willingness of investment to marshland culture development.