ABSTRACT
OBJECTIVE: To understand the epidemiological characteristics of patients with advanced schistosomiasis in Hunan Province, so as to provide the evidence for formulating the advanced schistosomiasis prevention strategies and measures. METHODS: The data of advanced schistosomiasis patients were collected and analyzed retrospectively with the cross section research method and description method in Hunan Province, 2012. RESULTS: There were 5 722 advanced schistosomiasis patients in Hunan Province, and among them, 4 112 patients were male (71.86%), and 1610 were female (28.14%). Totally 5311 patients came from the schistosomiasis endemic areas (92.82%) and 411 patients from non-schistosomiasis endemic areas (7.18%). The prevalence rate of advanced schistosomiasis was 8.46/10,000. The mean age of advanced schistosomiasis patients was 60.30 +/- 11.63 years, and the youngest was 17 years old and the oldest 92 years old. In the age composition of advanced schistosomiasis patients, the greatest number of cases was in the 60-70 years age group (32.72%). There were 3 595 cases of ascites type (62.83%), 2107 cases of splenomegaly type (36.82%), 11 cases of dwarf type (0.16%), and 11 cases of colon proliferation type (0.35%). CONCLUSION: The prevalence rate of advanced schistosomiasis is relatively stable in Hunan Province, and the age of the patients showed an old aging trend. The salvation of advanced schistosomiasis patients in non-endemic areas should be strengthened.
Subject(s)
Schistosomiasis/epidemiology , Adult , Age Distribution , Aged , Aged, 80 and over , China/epidemiology , Disease Progression , Educational Status , Female , Humans , Male , Middle Aged , Sex DistributionABSTRACT
OBJECTIVE: To understand the dynamic rules of schistosomiasis endemic situation before and after reaching the criteria of schistosomiasis transmission controlled or transmission interrupted, so as to provide the evidence for improving schistosomiasis control. METHODS: Wuling District, Xihu District and Linli County were selected and investigated retrospectively to collect the schistosomiasis epidemiological information 10 years before they reached the criteria of transmission controlled and the subsequent years until 2008. A database of retrospective investigation was established for analyzing the trends and rules of changes of the Oncomelania hupensis snail status and infection status of cattle and human. RESULTS: In Wuling District, the endemic situation was declining, and no schistosome infection persons, animals and snails were found after 1974. There was no rebound until 2008. In Xihu District, the endemic situation reached the criteria of transmission controlled in 1997, and the endemic situation was stable. The human infection rate was positively correlated with the area of infection snails (r = 0.584, P < 0.05). In Linli County, there were no snails, no infected persons and cattle twice, but 2 endemic rebounds, and there were positive correlations between the densities of living snails and the infection rates of human and animal during the endemic rebound period. CONCLUSION: The snail status is an important indicator of schistosomiasis endemic rebound. Therefore, the snail control is one of the most important schistosomiasis control measures.
Subject(s)
Cattle Diseases/epidemiology , Schistosomiasis/epidemiology , Schistosomiasis/veterinary , Adolescent , Adult , Aged , Animals , Cattle , Cattle Diseases/parasitology , Cattle Diseases/transmission , Child , China/epidemiology , Disease Reservoirs/parasitology , Female , Humans , Male , Middle Aged , Retrospective Studies , Schistosoma/physiology , Schistosomiasis/parasitology , Schistosomiasis/transmission , Snails/growth & development , Snails/parasitology , Young AdultABSTRACT
OBJECTIVE: To evaluate the short-term effect of the black film covering combined with niclosamide on Oncomelania hupensis snail control in marshland and lake regions. METHODS: A ditch with snails in Anxiang County was selected as the experimental sites. The ditch was divided into 3 groups: a film group, a niclosamide group, and a niclosamide and film group. The snails were surveyed before the test and 1, 3, 5, 7 days after the experiment. RESULTS: After the film covering, the highest temperature of the surface of soil was 63.7 degrees C on the first day, and the temperature higher than 40 degrees C lasted 4.34 hours. On the second day, the highest temperature was 52.3 degrees C, and the temperature higher than 40 degrees C lasted 4.96 hours. On the fourth day and fifth day, the temperature was lower than 30 degrees C, while the temperature was lower than 34 degrees C on the sixth day. On the seventh day of the experiment, the snail death rates of the film group, the niclosamide group, and the niclosamide and film group on the soil surface were 16.36%, 58.40% and 53.57%, respectively. On the seventh day, the snail death rates of the film group, and the niclosamide and film group under the soil were 20.00% and 40.00%, respectively, while no snails were found under the soil in the niclosamide group 3 days after the experiment. In mesh bags, the snail death rates of the film group, the niclosamide group, and the niclosamide and film group were 84.00%, 95.33% and 95.33%, respectively. CONCLUSION: The short-term effect of the black film covering on snail control is not obvious, and the black film covering does no promote the molluscicidal effect of niclosamide.
Subject(s)
Communicable Disease Control/methods , Molluscacides/toxicity , Niclosamide/toxicity , Pest Control/methods , Snails/drug effects , Animals , Communicable Disease Control/instrumentation , Lakes/chemistry , Snails/growth & development , Soil/chemistry , Temperature , WetlandsABSTRACT
OBJECTIVE: To investigate the current distribution of susceptible areas of schistosomiasis outside embankment, so as to provide the evidence for making comprehensive measures in Hunan Province. METHODS: The outside embankment areas where Oncomelania snails possibly or historically distributed and people and animals had activities were surveyed. The schistosomiasis information of the susceptible areas was collected, a database was set up, the positions were marked with GPS, an E-map was drawn with Google Earth, and the distribution was analyzed. RESULT: The number of marshlands with schistosomiasis susceptible areas outside embankment was 787, the length was 1,429.64 km, and the area was 6,2017.17 hm(2). The average density of living snails was 0.37 snails/0.1 m(2), and the average density of infected snails was 0.0019 snails/0.1 m(2). The infected snails were found in 180 marshlands, and the area was 688.07 hm(2). Sixteen rivers had the susceptible areas, and the main vegetation was weeds. CONCLUSIONS: The susceptible area of schistosomiasis outside embankment is wide and complex. Therefore, the comprehensive control measures should be strengthened.
Subject(s)
Schistosomiasis/prevention & control , Snails/growth & development , Animals , China/epidemiology , Communicable Disease Control , Disease Reservoirs/parasitology , Humans , Rivers/parasitology , Satellite Imagery , Schistosomiasis/epidemiology , Schistosomiasis/parasitology , Snails/parasitologyABSTRACT
OBJECTIVE: To evaluate the effect of an integrated control strategy and to quantify the spatial-temporal variation of infected snails in the bottomland areas after the strategy was implemented. METHODS: Based on the geographic database of infected snail distribution at the village level during 2004 - 2010 in Anxiang county, Hunan province, spatial autocorrelation analysis and spatial scan statistics were applied to analyze the spatial-temporal characteristics on the distribution of infected snails. RESULTS: The number of embankments with infected snails in Anxiang county decreased from 23 in 2004 to 10 in 2010, while the rate of frame with infected snail in embankments decreased from 4.32 in 2004 to 0.12 in 2010. The spatial distribution of infected snails was nonrandom, only in 2004 and 2005 with Moran's I = 0.21 (P < 0.10) and Moran's I = 0.13 (P < 0.10) respectively. Data from the local spatial auto-correlation analysis showed that the number of villages with H-H types of auto-correlation model had been gradually decreasing. The results of SaTScan statistics appeared the same as from the local spatial auto-correlation analysis, showing that the number of areas with increased risk was decreasing. CONCLUSION: The comprehensive measures with emphasis on infectious source control seemed effective for schistosomiasis control program. The current distribution characteristics provided us with evidence that the resource assignment could be more reasonably implemented so as to control schistosomiasis in a more effective way.
Subject(s)
Schistosomiasis/epidemiology , Schistosomiasis/prevention & control , Snails/parasitology , Spatio-Temporal Analysis , Animals , China/epidemiology , Geographic Information Systems , Infection Control/methods , Lakes , WetlandsABSTRACT
OBJECTIVE: To study the dynamic changes of the water body of rivers and Oncomelania snail habitats by using multi-temporal China-Brazil Earth Recourses Satellite-02 images taken in Anxiang County so as to establish the correct procedure for selecting images. METHODS: CBERS-02 images were collected on 20th December 2003, 10th February 2004, 10th April 2004, 19th June 2004, 10th August 2004 and 27th October 2004. Then the water body information from the study areas based on NDWI was extracted and the areas of water body were calculated to determine the images. RESULTS: The dynamic changes of the water body conformed to the rules of "water in summer and land in winter". Because of the rise of water, the water area in July was the biggest and the water area began to decline from August. The water area in April was the smallest. Then the wet season and the dry season should be June and April. CONCLUSION: The multi-temporal CBERS-02 images could be used to surveillance the dynamic changes of the water area and helpful in choosing the right images of the wet season and dry season.
Subject(s)
Ecosystem , Rivers , Satellite Communications , Snails/growth & development , Animals , EnvironmentABSTRACT
OBJECTIVE: To explore the spatial distribution and pattern of advanced schistosomiasis in Anxiang County so as to provide the evidence for improving advanced schistosomiasis control. METHODS: Based on the geographic database of advanced schistosomiasis distribution at the village level in Anxiang County, Hunan Province, the spatial autocorrelation analysis and spatial scan statistics were applied to analyze the spatial characteristics of distribution of advanced schistosomiasis. RESULTS: The global Moran's I of prevalence rate of advanced schistosomiasis was 0.06 (P > 0.05) and there was no spatial auto-correlation as a whole. The local spatial auto-correlation analysis showed that there were 9 villages with statistically significant LISA value (P < 0.05), among which existed high-high, low-high and high-low types of auto-correlation model. The results of SaTScan statistics was the same as local spatial auto-correlation analysis and showed the existence of one cluster area. CONCLUSIONS: There are local spatial auto-correlation and spatial aggregation of advanced schistosomiasis in Anxiang County. According to the distribution characteristics, we can assign resource more reasonably and control schistosomiasis more effectively.