Study On The Evaluation Of Epidemic Situation And Forecasting And Early Warning For Schistosomiasis

Objectives1. To evaluate the epidemic situation of schistosomiasis and the recent effect of the comprehensive schistosomiasis control program focusing on the main transmission cycles and reservoirs in order to further adjust the targets for schistosomiasis control and provide the theoretical basis for future schistosomiasis control strategies in China.2. To analysis the short-term change trend of the residents' infection rates of schistosomiasis so as to provide the methodological basis for short-term forecasting the infection rates of schistosomiasis.3. To establish the indicator system for schistosomiasis monitoring and early warning in order to put forward the effective references for the implementation of schistosomiasis monitoring and early warning system in China.4. To explore the strategies and intervention measures for improving the ability of schistosomiasis monitoring and early warning so as to provide the strategic support for schistosomiasis control in China.Methods1. Using descriptive epidemiological methods to analysis the longitudinal surveillance data of two national schistosomiasis surveillance sites, including Qianjiang City from 2005 to 2010 and Yangxin County from 2000 to 2009.2. Time series ARIMA model and grey model (1,1) were constructed to forecast the short-term change trend of the residents'infection rates of schistosomiasis using the annual report data from 1956 to 2010 in Qianjiang City.3. Literature review and data collection were used to form the questionnaire for expert consulting and opinion collection, then the methods of Delphi and the Analytic Hierarchy Process (AHP) were applied to screen the indicators and determine their internal weights for establishing schistosomiasis monitoring and early warning indicator system.4. SWOT analysis was used to explore the internal and external impact factors for improving the ability of schistosomiasis monitoring and early warning in China and putting forward corresponding strategies and intervention measures.Results1. The residents'infection rates of schistosomiasis in Qianjiang City and Yangxin County had decreased to 0.41% and 2.18%, respectively. The residents' parasitological prevalence of schistosomiasis decreased year by year (P for Cochran-Armitage trendχ2test was less than 0.05) and the farmers and males were still at high risk of schistosomiasis infection. The prevalence of cattle in two national surveillance sites of Qianjiang City and Yangxin County also decreased to 1.96% and 1.67%, respectively, but the situation of gracing of cattle in the grasslands was still very widespread. Additionally, the percentage of infected snails in two national surveillance sites of Qianjiang City and Yangxin County had dropped to 0.00% and 0.24%, respectively, whereas the total area of snail habitats was not obviously and effectively compressed.2. Time series ARIMA (1,1,0) model and grey prediction model were well fitted to the data of schistosomiasis infection. These two models were proved to be reasonable models with relatively high prediction accuracy. The actual values of schistosomiasis infection rates were all in the 95% confidence interval of the predictive values. The prediction results showed that the residents'schistosomiasis infection rates in Qianjiang City would continue to decrease slightly in the next two years.3. The indicator system for schistosomiasis epidemic situation monitoring and early warning included 5 first-level indicators,15 second-level indicators and 48 third-level indicators. Among these indicators, the first-level indicator of "schistosomiasis intervention measures" had the largest weight. The most important indicators in this indicator system included the impact factors of epidemic situation, such as the schistosomiasis infection rates of humans, the number of acute schistosomiasis infection last year and the schistosomiasis infection rates of cattle, and indicators of schistosomiasis epidemic situation outbreak and report, which were in accordance with the actual situation. The results of coordination coefficient test showed that the indicator system we established had high quality of authority and reliability.4. The advantages and opportunites for improving the ability of schistosomiasis monitoring and early warning in China were greater efforts on monitoring and the whole nation's attention, whereas no comprehensive monitoring and early warning system for schistosomiasis and the current severe situation of schistosomiasis in China were still the shortages and threats that we must face.Conclusions1. An integrated schistosomiasis control strategy focusing on the main transmission cycles and reservoirs which combines with chemotherapy, infrastructure interventions, health education and robust surveillance is feasible for effectively controlling schistosomiasis in China.2. Time series ARIMA model and grey model have showed high quality prediction accuracy. We can choose proper model for short-term forecasting of schistosomiasis according to the actual needs in the daily work of schistosomiasis control.3. The indicator system for schistosomiasis epidemic situation monitoring and early warning we have established could be used in the actual daily work after further verifying and amending.4. The ability of schistosomiasis monitoring and early warning in China still need to be improved and the workers of schistosomiasis control must judge the hour and size up the situation, seize the opportunies, adopt the good points and avoid the shortages so as to enhance the capacity of schistosomiasis control in China.Innovations1. Time series ARIMA model and grey prediction model were first applied to forecast the short-term change trend of the residents'infection rates of schistosomiasis in Qianjiang City of Hubei Province, which could provide the scientific basis for determining the priorities adjusting the targets for schistosomiasis control and provide the theoretical basis for future schistosomiasis control strategies in Hubei Province. 2. The indicator system was first established for schistosomiasis monitoring and early warning, which could provide a solid basis for the quantitative risk assessment of regional schistosomiasis outbreak or epidemic in China.3. A SWOT analysis was first used in the dicussion of strategies for improving the ability of schistosomiasis monitoring and early warning, which could provide strategic support for achieving the ultimate goal of schistosomiasis elimination in China.