Hupensis Snails Research Articles

Application of CroelDRAW software in drawing sketch map of schistosomiasis control

To improve the information level of schistosomiasis control by using the related functions of CorelDRAW software. Combining with the requirement of schistosomiasis control, the sketch map was drawn according to the linear element drawing, the geometric drawing, the color rendering and the text adding. The schistosomiasis epidemic sketch map and the Oncomelania hupensis snail distribution sketch map at all levels were produced in CorelDRAW software. The sketch map drawing in CorelDRAW software is beautiful and standardizing, and it can improve the level of information management.

Challenges and countermeasures of forestry schistosomiasis control programs in ecological priority of Yangtze River economic belt development

Relevant projects carried out within the Yangtze River economic belt on the impact of schistosomiasis epidemic and transmission are important issues for "ecological priority" in the process of implementing the strategy. The key problems of schistosomiasis epidemic risk, epidemic happening repeatedly, difficulty of rehabilitating Oncomelania hupensis snail control and schistosomiasis prevention forest, lag of evaluation system and platform construction, lack of basic research, et al. were analyzed in the Yangtze River economic belt taking "ecological priority" as the basis in this paper. Then corresponding countermeasures to these challenges were put forward so as to provide the reference for the national forestry schistosomiasis control programs, which include: execution of the comprehensive prevention and control strategy, scheming of the new round of forestry schistosomiasis control programs, strengthening schistosomiasis prevention and control, promoting productivity in existing forestry to consolidate and improve the achievements of previous forestry schistosomiasis control programs, and promoting the intensity of technological innovation to improve the technological level of forestry schistosomiasis control programs.

Endemic status of schistosomiasis in People's Republic of China in 2015

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2015, and analyzed the data collected from the national schistosomiasis prevention and control system and 457 national schistosomiasis surveillance sites. Among the 12 provinces (municipality, autonomous region) endemic for schistosomiasis japonica in P. R. China, 5 provinces (municipality, autonomous region), i.e., Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, had achieved transmission interruption, and 7 provinces of Sichuan, Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan had achieved transmission control by the end of 2015. There were 453 endemic counties (city, district) covering 252 million people, specifically including 29 980 endemic villages of 68.61 million people at risk of infection. Among the 453 endemic counties (city, district), 75.72% (343/453) and 24.28% (110/453) reached the criteria of transmission interruption and transmission control, respectively. By the end of 2015, it was estimated of 77 194 cases of schistosomiasis, which were decreased by 33.23% compared with 115 614 cases in 2014. No acute schistosomiasis cases were reported in 2015. There were 30 843 advanced schistosomiasis cases documented in 2015. A total of 8 736 036 individuals received schistosomiasis examinations and 3 606 individuals were parasitologically diagnosed, which were decreased by 56.40% compared with 8 270 cases in 2014. An Oncomelania hupensis snail survey was performed in 19 965 endemic villages and the snails were found in 5 609 villages, accounting for 28.09% of total villages, with 31 newly detected villages with snails. The snail survey covered an area of 593 572.66 hm2 and snails were found in an area of 173 462.50 hm2, including a newly detected area of 666.04 hm2. No infected snails were found in 2015. A total of 879 373 bovines were raised in the schistosomiasis endemic regions. Of them, 526 062 bovines received stool examinations, resulting in 315 infected bovines. There were 170 438 schistosomiasis cases receiving drug treatment in 2015, with 2 449 696 individuals undergoing expanded chemotherapy. There were 318 bovines with schistosomiasis receiving drug treatment, with 483 213 bovines undergoing expanded chemotherapy. A total of 144 305.52 hm2 area was subject to snail control by using molluscicides, with an actual molluscicide-treated area of 69 221.57 hm2, and 4 572.06 hm2 snail habitats were treated by environmental modification. Based on the data from the 457 national schistosomiasis surveillance sites, the mean Schistosoma japonicum infection rate was 0.05% and 0.04% in humans and bovines, respectively. No infected snails were found in all the surveillance sites. The results demonstrate a decline in the endemicity of schistosomiasis in P. R. China and the country reached the criteria of transmission control at the national level. However, the endemic situation of schistosomiasis is unstable in some regions with newly-reached transmission control, and further control and effective surveillance should be strengthened to consolidate the achievements and reduce the endemic situation of schistosomiasis in P. R. China.

Schistosomiasis control progress and endemic situation in Sichuan Province

To understand the schistosomiasis control progress and endemic situation, so as to provide the evidence for formulating the strategy of schistosomiasis elimination in Sichuan Province. The schistosomiasis history data, working reports of schistosomiasis prevention and control, schistosomiasis surveillance data, and data of schistosomiasis prevention and control capacity were collected and analyzed for the schistosomiasis control progress and epidemic situation in Sichuan Province from 2004 to 2015. There were 63 schistosomiasis endemic districts in 11 cities in Sichuan Province, and the standard of schistosomiasis transmission interruption was achieved in the whole province in 2015. Currently, the area with Oncomelania hupensis snails was 2 537.54 hm2, and there were 1 769 advanced schistosomiasis patients. From 2004 to 2015, the accumulated survey area with snails was 433 065.80 hm2, and the area of snail control by molluscicides was 251 259 hm2. There were 26.017 144 million person-times of schistosomiasis blood tests and 7.89 million person-times of chemotherapy. There were 1.276 117 million head-times of cattle that received the schistosomiasis examinations. The schistosomiasis patients and livestock and the area with snails were decreased year by year. Since 2010, there were no local schistosome-infected residents and livestock and since 2004, there were no schistosome-infected snails. However, in some area, the professional personnel were less, the technology and hardware lagged behind, and the schistosomiasis prevention and control capacity was weak. Sichuan Province achieved the standard of schistosomiasis transmission interruption in 2015. In the future, the comprehensive schistosomiasis prevention and control strategy still should be strengthened, including the promotion of schistosomiasis prevention and control capacity, establishment of sensitive early-warning surveillance system, and implementation of accurate schistosomiasis prevention and control, in order to consolidate the control achievements and realize the aim of schistosomiasis elimination as soon as possible.

Emergency response and effect evaluation on schistosomiasis control in rescue of shipwreck event in Yangtze River

To evaluate the effect of schistosomiasis control in"Oriental Star shipwreck event"in Jianli County, Hubei Province, so as to provide experiences for schistosomiasis prevention and control in rescue of emergency in the future. According to the data of historical schistosomiasis prevalence and the results of the field survey in the townships in the upstream and downstream of the rescue spots, the emergency handling measures of schistosomiasis control were evaluated. Meanwhile, the Oncomelania hupensis snail situation, priority crowd chemotherapy, key aquatic monitoring, and illness monitoring of people and livestock were investigated to evaluate the schistosomiasis control effect after the events comprehensively. There were no schistosome-infected snails found in the place of shipwreck and the rescue spots. The average density of O. hupensis snails in 5 townships of Jianli County was 0.064 snails/0.1 m2, and there were no infected snails found. The positive rate of 2 090 migrants in the schistosomiasis serologic tests was 0.29% and there were no positive ones found in the fecal examination. There were no acute schistosomiasis cases found by the sentinel surveillance fever clinics, and also no positive cattle were found. The results of sentinel mice monitoring in the place of shipwreck and 4 villages in the upstream and downstream showed no infected mice were found. The schistosomiasis control measures taken after the shipwreck is effective, which achieves the goal of no schistosomiasis transmission after emergency.

Endemic situation of schistosomiasis at national surveillance sites in Nanjing City, 2015

To understand the dynamic endemic situation of schistosomiasis in Nanjing City, 2015, so as to provide evidences for policy-making of schistosomiasis control. According to The National Scheme of Schistosomiasis Surveillance (2014), the endemic situation of schistosomiasis was monitored in 11 national surveillance sites in Nanjing. The positive rates of serological (IHA) and stool examinations were 2.97% (97/3 269) and 0 for local residents, and 0.52％ (12/2 298) and 0 for migrant people, respectively. No schistosome-infected livestock was found. Totally 147.295 3 hm2 area with Oncomelania hupensis snails were found, but no schistosome-infected snails were discovered. The endemic situation of schistosomiasis declines greatly in Nanjing City in 2015. However, the control work still should be strengthened to consolidate the achievements of schistosomiasis control.

Maximum entropy model versus remote sensing-based methods for extracting Oncomelania hupensis snail habitats

To explore the technique of maximum entropy model for extracting Oncomelania hupensis snail habitats in Poyang Lake zone. 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 Landsat 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 extract snail habitats. The ROC curve, sensitivities and specificities were applied to assess their results. Furthermore, the importance of the variables for snail habitats was analyzed by using Jackknife approach. 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 entropy 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 temperature (LST). The maximum entropy model is more reliable and accurate than the remote sensing-based method for the sake of extracting snail habitats, which has certain guiding significance for the relevant departments to carry out measures to prevent and control high-risk snail habitats.

Surveillance on schistosomiasis after its transmission interruption in Baoying County, Jiangsu Province

To understand the endemic situation of schistosomiasis after its transmission interruption in Baoying County, so as to provide the evidence for adjusting the prevention and control strategy. The data of schistosomiasis surveillance in Baoying County from 1988 to 2015 were collected and retrospectively analyzed. The schistosomiasis surveillance has been established since it was interrupted in Baoying County in 1987. The total surveyed area with Oncomelania hupensis snails was 21 269.95 hm2, but no living snails were found. The number of schistosomiasis examinations of residents was 163 196 person-times, and 270 person-times were positive in serum test, 26 person-times were positive in stool test. No positive cases were found since 1997. The number of schistosomiasis tests of livestock was 2 180 cattle-times but no infection was found. No schistosome infected snails or livestock are founded in Baoying County for last 28 years, and no patients are founded for last 11 years. The effect of schistosomiasis control is steady.

Impact of schistosomiasis transmission by catastrophic flood damage and emergency response in China

Flood damage is one of the ordinary natural calamities. The areas of middle and down of the Yangtze River and its south are the endemic area of schistosomiasis. As the flood damage, it causes property loss, and harm public and people health severely even. This paper aims at the status of catastrophic flood damage again in the Yangtze River basin, analyzes the impact of schistosomiasis transmission by it, and indicates that at present, the process of schistosomiasis control in China is marching from transmission control to transmission interruption and elimination, but the frequent flooding exacerbates Oncomelania hupensis snail breeding area and schistosomiasis source spreading, which may influence, in a certain extent, the realization of the goal of schistosomiasis control in China. We should timely assess and monitor the impact and risk of schistosomiasis transmission by flood damage, and give the early warning and adopt emergency handling measures in time. This paper also proposes the disaster prevention measures according to flood damage stages (the early, middle, later, and post-flood) and the occurrence and development of damage and endemic situation, so as to control the risk and damage of the disease transmission in a high limit, to consolidate the current achievements of schistosomiasis prevention and control and guarantee the realization of the goal of schistosomiasis interruption and elimination in China on the schedule.

Short - term effects of two kinds of plastic mulch on Oncomelania hupensis snail control in irrigation and drainage ditches in Yunnan Province

To evaluate and compare the short-term effects of two kinds of plastic mulch on Oncomelania hupensis snail control in irrigation and drainage ditches with snails in Yunnan Province. The irrigation and drainage ditches with high density of Oncomelania hupensis snails were chosen as the investigation sites, and then 4 groups were set, namely a colorless plastic mulch group, black plastic mulch group, colorless plastic mulch with molluscicide group and black plastic mulch with molluscicide group. The snail situation of the 4 groups was surveyed before the experiment and 7, 14, 21, 30 days after covering plastic mulch, and the snail death rates were compared among the 4 groups. Meanwhile, the hourly temperatures of soil surface, soil surface under plastic mulch and soil layer 5, 15 cm under the surface as well as the weather situation during the study period were measured and recorded. The average snail mortality rate of the colorless plastic mulch group was only 15.29% that was higher than that of the black plastic mulch group (6.56%) (P < 0.01). The average snail mortality rates of the colorless and black plastic mulch with molluscicide groups were 40.80% and 50.15%, respectively, and there was no statistic difference between them (P > 0.05). Both kinds of plastic mulches could raise the temperature of the soil surface under plastic mulch and the soil layer below it, and the temperature of soil under the mulches increased over the cover time, and the average temperature of the soil surface under the black mulch in 30 days was higher than that under the colorless mulch. It is not suitable to use plastic mulch only in irrigation and drainage ditches with snails widely in Yunnan Province because of its low effect, and if necessary, the molluscicide should be added.

Role of goat in transmission of schistosomiasis japonica III Environmental contamination by goat feces and prediction of environments at high risk of S. japonicum infection

To quantitatively estimate the range and area of environmental contamination by the feces of Schistosoma japonicum-infected that were freely grazed, so as to provide the theoretical evidence for the scientific assessment of the role of the freely grazed goat in the transmission of schistosomiasis japonica and development of control strategy. All the fecal samples excreted by the infected goat at daytime (12 h) were collected by using a self-made goat fecal collector, weighed and counted. The quantity and dispersal of the feces excreted by the freely grazed goat at daytime under a natural condition were investigated, and the walking route and speed of the freely grazed goat at daytime were recorded with a multifunction GPS data logger. The maximum range and area of the environment contaminated by the feces of the freely grazed goat at daytime were estimated, and the maximum range and area of the Oncomelania hupensis snails that may be infected by the schistosome miracidium released from the eggs in the fecal samples of the freely graze goat at daytime were calculated. During the walking along the marshland at daytime (12 h), the quantity of the feces execrated by the freely grazed infected goat was (232.8 ± 39.8) g per goat, and the fecal samples were composed of (819.2 ± 152.1) pellets. The goat had a mean walking speed of (0.522 7 ± 0.099 7) km/h, and the longest distance, largest radius and largest range of walking activity were (6.272 4 ± 1.195 8) km, 3.136 2 km and (3 191.113 0 ± 1 189.709 4) hm2 at daytime, respectively. The area of the snails that may be infected by the miracidium released from the eggs in the fecal samples of the freely graze goat (range of key regions for infected snails detection and control) at daytime was estimated to be (3 210.717 5 ± 1 190.907 3) hm2. The intensity of environmental contamination by the eggs in the fecal samples of the freely grazed goat is linked to the number of infected goat. The contamination range caused by the feces of the freely grazed goat with fixed fences is relatively stably kept within the walking range at day-time, and the range and area of goat fecal contamination is associated with the number of households that breed goat and the distribution of goat fence. The area of the snails that may be infected by the miracidium released from the eggs in the fecal samples of the freely graze goat is larger than the area of setting contaminated by the eggs in the goat feces, indicating that the range of infected snail examination and control is larger than the range of goat feces detected.

Role of goat in transmission of schistosomiasis japonica IV Goat breeding in endemic regions and role of goat in schistosomiasis transmission

This review describes the major species, number, breeding pattern, ratio of fenced to freely grazed goat, susceptibility to Schistosoma japonicum, pattern of S. japonicum infection, infection rate, intensity of infection, fecal contamination of goat that were bred in 5 marshland and lake provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu, and two mountainous provinces of Yunnan and Sichuan, and demonstrates the associations of infected goat distribution with the distribution of infected Oncomelania hupensis snails and humans. Considering the huge number of goat which were predominantly grazed freely in marshland and lake endemic regions of China, the high infection rate, numerous environmental pollution by goat feces, as well as the close correlation between the infected goat distribution and infected snail distribution, goat is considered as a major infectious source for schistosomiasis japonica in China, and to play a critical role in the transmission of the disease. Since the control of schistosomiasis in animals is critical to schistosomiasis interruption and elimination, it is suggested that the integrated management of goat schistosomiasis should be included in the national schistosomiasis control program of China.

Oncomelania hupensis snail distribution in working areas of Yangtze River hydrologic agencies located in middle and lower reaches of Yangtze River in 2016

To understand the Oncomelania hupensis snail distribution in the working areas of Yangtze River hydrologic agencies located in the middle and lower reaches of the Yangtze River in 2016, so as to provide the evidence for assessing the risk of schistosome infection of hydrological workers and establishing the control strategies. The suspicious environments with O. hupensis snails in the above working areas were selected as study areas, and the snail situation was surveyed by the system sampling method combined with the environmental sampling method. The survey data were collected and analyzed statistically. Totally 19 working areas from 17 hydrological agencies were selected as the investigation sites, among which, 10 working areas from 9 agencies were found with O. hupensis snail distribution. The constituent ratio of the areas with snails reached to 38.81% of the investigation areas, the occurrence rate of frames with snails was 3.08%, and the average density of living snails was 0.07 /0.1 m2. By comparison, the average density of living snails and occurrence rate of frames with snails in hydrological agencies under the jurisdiction of the Middle Reaches Administrative Bureau were the most serious among three administrative bureaus of the Yangtze River Water Resources Commission. There are various degrees of O. hupensis breeding in the working areas of hydrological agencies located in the middle and lower reaches of the Yangtze River, and the hydrological workers are facing with the risk of schistosome infection.

Study on interventions based on systematic ecological system construction to interrupt transmission of schistosomiasis in hilly endemic regions

To study the effectiveness of comprehensive control measures based on systematic ecological system construction to interrupt the transmission of schistosomiasis in hilly endemic regions in Sichuan Province, so as to provide the evidence for adjustment of schistosomiasis prevention and control strategies. A high endemic area of schistosomiasis, Panao Township of Dongpo District in Meishan City, was selected as a demonstration area. The comprehensive measures for schistosomiasis control with focus on systematic ecological management were implemented, and the income of residents, indexes of schistosomiasis control effect and so on were investigated before and after the intervention and the results were compared. The project based on systematic ecological system construction started in 2009 and 317.351 million Yuan was put into the construction. The construction included economic forest plant base (1 866.68 hm2, 72.66% of the total farmland areas), ecological protection gardens (585.35 hm2) and so on. Totally 97.04% of historical areas with Oncomelania hupensis snails were comprehensively improved. In 2015, the peasants´ pure income per capita increased 4 938 Yuan, with the average annual growth rate of 14.69%. All the farm cattle were replaced by the machine. The benefit rate of water improvement was increased by 52.84% and the coverage rate of harmless toilets increased by 18.30%. The positive rate of serological tests for schistosomiasis decreased from 7.69% to 3.50%, and the positive rate of parasitological tests decreased from 1.18% to 0. The area with snails was decreased from 23.33 hm2 to 0. The awareness rate of schistosomiasis control knowledge and correct behavior rate of the residents increased from 85.50% and 82.60% to 95.70% and 93.90% respectively. The comprehensive schistosomiasis control measures based on systematic ecological management are conform to the currently actual schistosomiasis prevention and control work in hilly endemic regions, and have good ecological economic benefit and schistosomiasis control effectiveness, which provide an effectively new model of prevention and control for advancing process, consolidating the effect, finally realizing goal of interruption and elimination of schistosomiasis in hilly endemic regions.

Evaluation on capability of parasitic disease control and prevention among professional and technical personnel in medical and health institutions in Wuxi City

To understand the capability of parasitic disease control and prevention among professional and technical personnel in medical and health institutions in Wuxi City, so as to provide the evidence for promoting relative capability building. Forty-one professional and technical persons from 22 medical and health institutions received the evaluation through the theoretical knowledge exam and laboratory operation skill assessment. The average score of theoretical knowledge exam was (76.5±15.6) with the pass rate of 80.5% and excellent rate of 48.9%. The average score, pass rate and excellent rate for Plasmodium blood slide making were (7.3±1.5), 87.8% and 41.5% respectively, the average score, pass rate and excellent rate for Plasmodium blood slide reading were (14.0±7.2), 31.7% and 12.2% respectively; the average score, pass rate and excellent rate for helminthes microscope examination were (19.4±10.4), 24.4% and 0 respectively; the average score, pass rate and excellent rate for Oncomelania hupensis snail identification were (8.6±1.1), 95.1% and 73.2% respectively. The average scores of helminthes microscope examination and Oncomelania hupensis snail identification were higher in the participants with middle-level professional title or above than in the participants with primary level professional title (both P < 0.05). The average scores of theoretical knowledge exam, Plasmodium blood slide reading and helminthes microscope examination were higher in the participants from disease control and prevention institutions than in the staff who came from medical institutions (all P <0.05). The professional and technical personnel in medical and health institutions in Wuxi do better in theoretical knowledge, Plasmodium blood slide making and Oncomelania hupensis snail identification. However, the capability of parasite microscope examination is urgently needed to be improved in the future.

Surveillance with sentinel mice in key water areas of schistosomiasis endemic regions in Yunnan Province, 2015

To carry out the surveillance with sentinel mice in the key water areas of schistosomiasis endemic regions in Yunnan Province, so as to establish and perfect the surveillance and forecast system of schistosomiasis. Six villages of three counties with schistosomiasis heavy endemic status were selected as the survey points. Then, the surveillance and forecast with the sentinel mice were carried out in the key water areas in the survey points. The recovered sentinel mice were dissected in laboratory, and their serum antibodies against schistosome were detected. Meanwhile, the suspicious infested water contacts of the residents and livestock in the surveillance sites were investigated, and the endemic data of schistosomiasis in the survey points in recent 3 years were collected and analyzed. Totally 282 sentinel mice were placed in the water area, 252 were recovered, with a recovery rate of 90.78%, and 8 mice were dead, with a mortality rate of 3.13%. The number of mice with schistosome egg granuloma and adult worm detected were both 0, and the worm burden and the positive rate of serum antibodies against schistosome were both 0, too. The persons who contacted with the suspicious infested water were mainly villagers and students by harvesting and playing. The Oncomelania hupensis snail areas, the infection rates of residents and livestock were obviously declined in recent 3 years. There are no positive sentinel mice found in the key water areas of the surveillance sites in Yunnan Province, which suggests that the schistosome infection risk of residents and livestock is low. However, the comprehensive control measures, surveillance and forecast with sentinel mice in the key water areas of schistosomiasis endemic regions still should be strengthened.

Schistosomiasis endemic situation of national surveillance sites in Mianyang City, 2015

To master the dynamics of schistosomiasis endemic situation and influencing factors in Mianyang City, so as to provide the evidence for making the control and prevention measures. Six villages of six schistosomiasis heavy endemic counties were selected as survey sites according to the national surveillance protocol (Revision in 2014) in Mianyang City. The surveys of the incidences of schistosomiasis in population and livestock as well as the prevalence of Oncomelania hupensis snails were conducted in the 6 national surveillance sites. The serum positive rates of local residents and migrant people were 2.12% and 1.71%, respectively. The infection rate of cattle was 0. The area with snails was 9.344 8 hm2. The mean density of living snails was 0.25/0.1 m2. The occurrence rate of frames with snails was 7.07%, and no infected snails were found. The infection rates of schistosome in human and livestock are low and the prevalence of O. hupensis snails is stable in the national surveillance sites in Mianyang City. However, the schistosomiasis transmission risk still exists, therefore, we should strengthen the control measures to prevent the rebound of the endemic.

Status and challenges for schistosomiasis in transmission-interrupted areas in Jiangxi Province

This report analyzes the status of schistosomiasis epidemic, surveillance and challenges in transmission-interrupted areas of Jiangxi Province. There are 24 schistosomiasis transmission interrupted counties (cities, districts) among 39 endemic counties (cities, districts). Among the 24 counties, there are 6 counties with Oncomelania hupensis snails and 461 villages endemic, with 1.29 million residents. Since 2009, there have not been acute and chronic cases of schistosomiasis and all the patients are historical advanced schistosomiasis cases. The area with snail habitats is 37.02 hm2. Since 2015, the schistosomiasis surveillance has covered the entire transmission interrupted areas. However, there are still many challenges, such as endemic instability, weak surveillance capacity, lack of surveillance awareness and other issues. Towards the schistosomiasis elimination, the surveillance should be based on the snail monitoring mainly, supplemented by the mobile population monitoring, and in addition, the capacity building, standardized report of endemic, and snail habitat reform should also be further strengthened.

Evaluation of transmission control of schistosomiasis in 19 counties (cities, districts) of Hubei Province in 2013

To evaluate the schistosomiasis transmission control in 19 counties (cities, districts) of Hubei Province in 2013. The epidemic villages from different counties were randomly sampled by the cluster sampling method as the evaluation villages. The schistosome infection status of human and livestock, the Oncomelania hupensis snail status, the documents and data of schistosomiasis control, acute infection control and health education were investigated in the field. The serum examination of schistosome infection was performed to 29 631 residents, and 2 068 were positive, with a positive rate of 6.98% (0.78% -16.47%). The stool examination was performed to 2 021 sero-positive persons, and 47 cases were stool-positive, with an infection rate of 0.16% (0 - 0.82%). The cattle was the main domestic animals in 19 counties (cities, districts), and the measures of replacing cattle with machine for cultivation were done in 17 counties (cities, districts). Totally 105 cattle in Caidian District and Huangpi District received stool examinations and no positives were detected. A total of 1 579.37 hm2 and 31 829 frames in 154 environments were surveyed, and 4 857 snails were collected. Of the 1 935 living snails dissected, no infected snails were detected. The files regarding the schistosomiasis morbidity and snail status have been established in 19 counties (cities, districts) since 2009. The transmission of schistosomiasis in 19 counties (cities, districts) of Hubei Province has reached the standard of transmission controlled.

Oncomelania hupensis snail control effects of molluscicides with different formulations in field in marshland and lake regions

To observe the Oncomelania hupensis snail control effects of molluscicides with different formulations in the ditch with unstable water level in field of marshland and lake areas, so as to provide the evidence for formulating the prevention strategies. A drainage channel with O. hupensis snails in Jiangling County, Jingzhou City were selected as the study field, then it was divided into 6 segments, except 1 segment was treated as the blank control group for observing the natural mortality rate of the snails, the other 5 segments were treated as observation groups, where 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granule, 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder were applied respectively. Before and after the mollusciciding, the snail surveys were carried out through the systematic sampling method, and the short- and long-term effects of snail control were observed, and the mortality rates of the snails on the slope above the water level and those below the water level were compared. When 7 d and 15 d after mullusciciding, the mortality rates of snails on the slope above the water level in each observation group were 79.52%-97.87% and 90.43%-96.30%, respectively, when compared with those before mollusciciding, all the differences were statistically significant (all P < 0.01). When 7 d after mullusciciding, the mortality rates of snails below the water level in each observation group were 17.11%-50.00%, which were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.05); when 15 d after mullusciciding, the rates were 9.43%-95.24%, and those in 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder groups were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.01). Compared with the densities of living snails before mollusciciding, those 6 months after mollusciciding in each observation group decreased by 70.21%-78.98%. The molluscicides in the formulation of powders and granule are suitable for both the snail environment with or without water, while those in the formulation of suspension agents and wettable powders are suitable only for environments with water.