Study On The Epidemic Situation And Prediction For Schistosomiasis In Jiujiang Region Of Poyang Lake Eco-economic Zone

Objective:(1)To analyze the epidemic status and trends of schistosomiasis prevalence in Jiujiang region of Poyang Lake Eco-economic Zone.And to provide reference for formulating goals and adjusting strategies of schistosomiasis control program in future.(2)To verify the feasibility of forecasting the schistosomiasis prevalence by using grey model,so as to provide methodological basis for building schistosomiasis early warning system.Method:(1)The annual data of schistosomiasis prevention and control from 2003 to 2015 were collected to analyze the schistosomiasis patients' condition,the state of livestock and the data of oncomelania by using trend Chi-square tests.(2)On the basis of schistosomiasis epidemic data from 2005 to 2014,we use the grey system GM(1,1)to establish original model,to predict the result dynamically using “Same Dimension-Progressively Increased Grey Dynamic Prediction”,and to modify the prediction results by considering the “Environment Interference Factors”.In order to evaluate the prediction effect,we compare the actual data and predicted values of schistosomiasis epidemics in 2015.Results:(1)From 2003 to 2015,the number of counties which have reached the criteria of transmission interruption of schistosomiasis increased from 2 to 4,and the number of counties which have reached the criteria of infection controlled increased from 5 to 9,the number of counties where the transmission was not controlled reduced to zero.The positive rate of serological test and fecal examination in residents decreased significantly,the human infection rates of schistosomiasis dropped dramatically(below 0.01%).Acute infection reduced from 49 cases to zero,advanced cases increased from 2003 to 2010,and reduced after 2011.The incidence of advanced schistosomiasis tended to decrease with fluctuation.The positive rate of cattle was decreased from 3.74% in 2003 to 0.07% in 2015.The oncomelania area maintained between 24000~24800 hm~2,and enhanced slowly from 2005 to 2015.Area with oncomelania control activities increased by 59.54%.(2)The prediction models about the human infection rates of schistosomiasis,positive rate of cattle and oncomelania area were fitted,the model fitness effects were fairly good.The mid-time and long-term prediction results from 2016 to 2020 showed that the human infection rates were 0.0078%,0.0021%,0.0003%,0.0003%,0.0002%,respectively;the positive rates of cattle were 0.1466%,0.0580%,0.0208%,0.0214%,0.0249%,respectively;and the oncomelania area were 24850.69 hm~2,24915.83 hm~2,24974.10 hm~2,25030.61 hm~2,25124.46 hm~2,respectively.In summary,the human infection rates and the positive rates of cattle showed declining trend,there was a slow increasing trend for oncomelania area.Conclusion:The schistosomiasis prevalence in Jiujiang region of Poyang Lake Eco-economic Zone showed a declining trend overall,but the oncomelania area may rise in a few years.The grey model had a good fit and accuracy to predict the schistosomiasis prevalence.