ABSTRACT
Objective To investigate the prevalence of Schistosoma japonicum infection in wild mice in Shitai County, Anhui Province, so as to provide insights into precise control of the source of S. japonicum infections. Methods Wild mice were captured using the trapping method for three successive nights at snail-infested settings from Jitan Village of Jitan Township, and Shiquan Village and Xibai Village of Dingxiang Township, Shitai County, Anhui Province in June and October, 2018. All trapped wild mice were sacrificed and liver and mesenteric vein specimens were collected for detection of S. japonicum eggs using microscopy, while the fecal samples in mouse intestines were collected for identification of S. japonicum infections using Kato-Katz technique. In addition, the population density of trapped wild mice was estimated and the prevalence of S. japonicum infection was calculated in trapped wild mice. Results A total of 376 wild mice were trapped from three villages in Shitai County. The population density of trapped wild mice was 9.1% (376/4 124), and the prevalence of S. japonicum infection was 24.2% (91/376) in trapped wild mice. The highest prevalence of S. japonicum infection was detected in Shiquan Village of Dingxiang Township (30.1%), and the lowest prevalence was seen in Xibai Village of Dingxiang Township; however, there was no significant difference in the prevalence of S. japonicum infection in trapped wild mice among three villages (χ2= 4.111, P > 0.05). In addition, there was no significant difference in the prevalence of S. japonicum infection in wild mice captured between on June (26.8%, 34/127) and October (22.9%, 57/249) (χ2 = 0.690, P = 0.406). The trapped wild mice included 6 species, including Rattus norvegicus, Niviventer niviventer, R. losea, Apodemus agrarius, Mus musculus and N. coning, and the two highest prevalence of S. japonicum infection was detected in R. losea (34.9%, 22/63) and R. norvegicus (31.2%, 44/141). Conclusions The prevalence of S. japonicum infections is high in wild mice in Shitai County, and there is a natural focus of schistosomiasis transmission in Shitai County.
ABSTRACT
Objective To analyze the endemic situation of schistosomiasis in national surveillance sites of Anhui Province from 2015 to 2018, so as to provide scientific evidence for schistosomiasis control and prevention in Anhui Province. Methods According to the National Schistosomiasis Surveillance Programme (2014 version), a total of 51 national schistosomiasis surveillance sites were assigned in Anhui Province in 2015, and Schistosoma japonicum infections in humans and livestock and snail distribution were monitored from 2015 to 2018. Results A total of 89 638 local residents and 42 609 mobile populations received serological screening of schistosomiasis in 51 national surveillance sites of Anhui Province from 2015 to 2018, and the sero-prevalence of S. japonicum infections was 1.41% to 3.69% in local residents and 0.84% to 2.13% in mobile populations, respectively. There were 5 egg-positive local residents and 1 egg-positive mobile populations detected in 2015, with occupations of farmers and fishermen. There were 6 405 livestock detected for S. japonicum infections, and no egg-positives were identified. Among an area of 12 661 hm2 surveyed in the national schistosomiasis surveillance sites of Anhui Province from 2015 to 2018, the areas of snail habitats were 2 461.27 to 2 628.96 hm2, andthemeandensityoflivingsnailswas 0.3757 to 0.4330 snails/0.1 m2, with no S. japonicum infections identified in snails. Conclusions The endemic situation of schistosomiasis is at a low level in Anhui Province; however, the risk of schistosomiasis transmission remains in local regions of the province. The construction of the surveillance-responsesystemshouldbereinforcedtoconsolidatetheachievementsofschistosomiasis control in Anhui Province.
ABSTRACT
Objective To investigate the spatiotemporal distribution of Oncomelania hupensis snails and infected snails in the endemic areas of schistosomiasis in Anhui Province. Methods Based on the snail survey data in Anhui Province in 2016, the distribution of snails and infected snails were analyzed, and the spatial distribution of snails and spatial cluster patterns of infected snails were investigated in snail habitats in Anhui Province from 1950 to 2016. Results A total of 22 757 snail habitats and 5 004 infected snail habitats were identified in Anhui Province from 1950 to 2016, which appeared single-peak and double-peak patterns, with an inflection point seen in 1970. There were 141 000 hm2 historically accumulative snail habitats, 88.08% of which were firstly identified from 1950 to 1979, and totally 114 500 hm2 snail habitats were eradicated, 77.17% of which were eradicated from 1970 to 1999. There were 4 830 snail habitats identified until 2016, in which 1 051 were once detected with infected snails. In addition, 78.12% of current snail habitats had been present for over 40 years, and infected snails had been eliminated in 65.75% of the infected snail habitats within 10 years. There was a spatial autocorrelation of the living snail density in current snail habitats in Anhui Province (Moran’s I = 0.196, Z = 139.63, P < 0.001), and local hotspot analysis showed spatial clusters of living snails density in snail habitats, with high-value clusters in south of the Yangtze River and low-value clusters in north of the Yangtze River. The 21 high-value clusters of living snail density with statistical significance were distributed along the Yangtze River basin and its branches. Spatiotemporal scan analysis revealed spatiotemporal clusters of infected snails in 4 current snail habitats. Conclusions The current snail habitats have been present for a long period of time, and snails are difficult to be eliminated by chemical treatment alone, which requires the combination of environment improvements. There are spatial clusters of living snail density in current snail habitats in Anhui Province. The epidemic factors and risk of human and animal infections still remain in some clusters of historical infected snail habitats revealed by spatiotemporal scan analysis, which should be consid- ered as the key target areas for snail control in Anhui Province.
ABSTRACT
Objective To investigate the species and activities of wild animals infected with schistosome in hilly and mountain areas by using an infrared camera technique, so as to provide the evidence for the surveillance of schistosomiasis in these areas. Methods Six infrared cameras were selected and placed in 6 environments of the risk monitoring points of schistosomiasis in Shitai County in Anhui Province. The species and activities of the wild animals in the 6 environments were observed through the photographs and videos taken by the cameras. Results Through 5 day’s monitoring, 3 wild mammals, such as voles, hares and wild boars, were found in 4 monitoring environments, of which voles were found at 2 environments with snails, and hares, wild boars and voles were found in 2 environments adjacent to environments with snails respectively. The monitoring showed that the vole activity was most frequent in the monitored environment. Conclusion The use of infrared camera technique has a good effect in the investigation of wild animal infectious source of schistosomiasis, and it is also suitable for the monitoring work in other types of environments.
ABSTRACT
Objective To investigate the status of Oncomelania hupensis snails in Anhui Province in 2016, so as to provide the evidence for formulating the 13th Five-Year Plans for Schistosomiasis Control. Methods In 2016, a snail survey was conducted in Anhui Province according to the National Programme of the Oncomelania Snail Survey, covering all snail habitats or historical snail habitats and suspected environments of snail breeding, and the results of the survey were analyzed. Results In 2016, 22 848 environments were surveyed, and no schistosome-infected snails were found. There were 17 927 historical snail habitats in whole province, among which, the environments without changes, changed partly and changed completely accounted for 71.2%, 19.3% and 9.5%, respectively. The area of historical snail habitats was 1.410 billion m2. There were 4 830 environments with snail habitats covering an area of 0.265 billion m2 in 38 counties of 7 cities, including newly emerging area of 1 287.65 hm2 and reemerging area of 1 375.32 hm2. The density of living snails was 0.392 0 snails/0.1 m2, and the rate of frame with living snails was 12.93%. The type of marshland and lake regions, and the type of hilly and mountainous regions accounted for 22.4% and 77.6% of number of snail habitats, and accounted for 86.7% and 13.3% of areas of snail habitats, respectively. Among the different types of vegetation in snail habitats, grass was superior owe to accounting for 82.2% of the number of snail habitats, 57.3% of the area with snail habitats, and the highest density of living snails (0.413 9 snails/0.1 m2). Among the different types of environments in snail habitats, the ditch was superior owe to accounting for 56.8% of the number of snail habitats, the highest density of living snails (0.570 3 snails/0.1m2) and the highest rate of frame with living snails (18.57%), and the beach was superior owe to accounting for 87.8% of the area with snail habitats. In Anhui Province, the first year of snails and schistosome-infected snails being found was 1950 and 1952, respectively, and the latest year of schistosome-infected snails being found was 2012. The map showed that the most environments with snail habitats were distributed along the Yangtze River in Anhui Province. Conclusion For the first time, the investigation has built the database and map of snail spatial distribution, which truly reflect the historic and current status of snail distribution in Anhui Province and can provide the evidence for formulating the 13th Five-Year Plans for Schistosomiasis Control and improving the schistosomiasis prevention and control work in the future.
ABSTRACT
Objective To investigate the status of Oncomelania hupensis snails in Anhui Province in 2016, so as to provide the evidence for formulating the 13th Five-Year Plans for Schistosomiasis Control. Methods In 2016, a snail survey was conducted in Anhui Province according to the National Programme of the Oncomelania Snail Survey, covering all snail habitats or historical snail habitats and suspected environments of snail breeding, and the results of the survey were analyzed. Results In 2016, 22 848 environments were surveyed, and no schistosome-infected snails were found. There were 17 927 historical snail habitats in whole province, among which, the environments without changes, changed partly and changed completely accounted for 71.2%, 19.3% and 9.5%, respectively. The area of historical snail habitats was 1.410 billion m2. There were 4 830 environments with snail habitats covering an area of 0.265 billion m2 in 38 counties of 7 cities, including newly emerging area of 1 287.65 hm2 and reemerging area of 1 375.32 hm2. The density of living snails was 0.392 0 snails/0.1 m2, and the rate of frame with living snails was 12.93%. The type of marshland and lake regions, and the type of hilly and mountainous regions accounted for 22.4% and 77.6% of number of snail habitats, and accounted for 86.7% and 13.3% of areas of snail habitats, respectively. Among the different types of vegetation in snail habitats, grass was superior owe to accounting for 82.2% of the number of snail habitats, 57.3% of the area with snail habitats, and the highest density of living snails (0.413 9 snails/0.1 m2). Among the different types of environments in snail habitats, the ditch was superior owe to accounting for 56.8% of the number of snail habitats, the highest density of living snails (0.570 3 snails/0.1m2) and the highest rate of frame with living snails (18.57%), and the beach was superior owe to accounting for 87.8% of the area with snail habitats. In Anhui Province, the first year of snails and schistosome-infected snails being found was 1950 and 1952, respectively, and the latest year of schistosome-infected snails being found was 2012. The map showed that the most environments with snail habitats were distributed along the Yangtze River in Anhui Province. Conclusion For the first time, the investigation has built the database and map of snail spatial distribution, which truly reflect the historic and current status of snail distribution in Anhui Province and can provide the evidence for formulating the 13th Five-Year Plans for Schistosomiasis Control and improving the schistosomiasis prevention and control work in the future.
ABSTRACT
Objective The characteristics of spatial-temporal distribution on infected snails were analyzed at the village level in Anhui province,2006-2012.Methods Data on the distribution of infected snails from 2006 to 2012 in Anhui province was collected.Spatial database was established by ArcGIS 9.3.Retrospective spatial-temporal cluster analysis was done by SaTScan 9.1.1 at the village level.Results Eight areas with increased risk and distributed along the upstream to downstream of Yangtze and connecting branch rivers,were found having infected snails,from 2006 through 2012,including one area in 2006,five in 2006-2008,one in 2007-2009 and one in 2009-2011,respectively.Proportion on the number of areas with infected snails decreased from 6.2％ in 2006 to 0.5％ in 2012.Conclusion The spatial-temporal distribution of infected snail was not random but there appeared significant clusters.The trend seemed to be declining in Anhui province,between 2006 and 2012.Areas being detected as smails positive were important for the schistosomiasis control program to be carried out in Anhui province.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of comprehensive control strategy of schistosomiasis with emphasis on infection source control in Anhui province.</p><p><b>METHODS</b>Forty endemic villages in Guichi district, Chizhou city, Anhui province were selected as national pilot villages in the years from 2006 to 2008, and another 10 provincial pilot villages were respectively selected from 10 highly endemic villages in 7 cities in 2007. The comprehensive infection source control measures, including "replace cattle with machines", "raise livestock in pens", "improve the sanitary toilets", "supply safe water " and so on were carried out among the above pilot villages. At the end of 2008, 13 national pilot villages and 6 provincial pilot villages were selected to investigate the popularity of schistosomiasis, and the effect of the comprehensive control strategy in those villages were compared.</p><p><b>RESULTS</b>After implementing the comprehensive control strategy, the infectious rate of schistosomiasis in national pilot villages decreased from 4.57% (487/10 659) to 1.76% (147/8370), with the reduction rate at 61.49%, whose difference showed statistical significance (χ(2) = 115.16, P < 0.01); and the density of infected snails decreased from 0.0067/0.1 m(2) to 0.0008/0.1 m(2), the infectious rate of snails decreased from 0.28% to 0.04%, whose reduction rates were 88.06% and 85.71% respectively. While as to the provincial pilot villages, the infectious rate of schistosomiasis decreased from 1.27% (54/4254) to 0.21% (14/6592), with the reduction rate at 83.46%, whose difference showed statistical significance (χ(2) = 94.57, P < 0.01); and the density of infected snails decreased from 0.0025/0.1 m(2) to 0.0003/0.1 m(2), the infection rate of snails decreased from 0.13% to 0.05%, whose reduction rates were 88.00% and 61.54% respectively.</p><p><b>CONCLUSION</b>The comprehensive control strategy with emphasis on infection source control implemented in marshland and lake regions can effectively control the transmission of schistosomiasis.</p>
Subject(s)
Animals , Humans , China , Epidemiology , Disease Reservoirs , Parasitology , Infection Control , Methods , Livestock , Pilot Projects , Rural Health , Schistosomiasis , Epidemiology , Parasitology , Snails , ParasitologyABSTRACT
<p><b>OBJECTIVE</b>To analyze the outbreak patterns of acute schistosomiasis in Anhui province in 2003.</p><p><b>METHODS</b>The criteria of emergency event for schistosomiasis issued by the Ministry of Health were applled in this study. Epidemiological data of acute schistosomiasis outbreak in Anhui province in 2003 were collected, checked and analyzed.</p><p><b>RESULTS</b>In 2003, there were 6 episodes of acute schistosomiasis outbreaks in Anhui which had met the criteria of being emergency events, issued by the Ministry of Health. The preplanning was initiated in 5 outbreaks to respond to the outbreaks of acute schistosomiasis. All of the acute schistosomiasis cases received timing treatment, except those misdiagnosed cases coming from the non-endemic areas. There were no deaths or follow-up cases during the outbreaks. Health education, preventive treatment for people living in high risk villages were conducted in order to timely control the epidemics of schistosomiasis.</p><p><b>CONCLUSION</b>The implementation of preplanning has played an important role in early cases-finding, timing report and response to the outbreaks of acute schistosomiasis.</p>