ABSTRACT
Objective The aim is to analyze the spatial-temporal correlation of dysentery incidence in 31 provinces, municipalities and autonomous regions in China from 2004 to 2016, and to predict the short-term incidence of dysentery in China. Methods Data about the incidence of dysentery from 2004 to 2016 was collected. Arcgis and Geoda were used to create visualized grading maps and analyze spatial correlation. The auto-regressive integrated moving average model (ARIMA)was used to predict the incidence of dysentery in 2017 and evaluate the prediction accuracy of the model. Results The incidence of dysentery in China declined with each passing year from 2004 to 2016. The incidence of dysentery in the western region was significantly higher than the eastern region, except high incidence rate in Beijing and Tianjin. There was no significantly global correlation in the incidence rate, but there was local aggregation. Qinghai had turned from high-level aggregation to low-level accumulation. Inner Mongolia and Shanxi had changed from no local aggregation to low-high accumulation. Shaanxi has long been high-high, and the southeast coastal areas had been low-low accumulation for a long time. The optimal model ARIMA (1,0,0) (2,1,1)12 was established to predict the incidence of dysentery, and the prediction results were roughly consistent with the observations. Conclusion The incidence of dysentery from 2004 to 2016 is not spatially mobile but clustered. The incidence of dysentery in Beijing, Tianjin, Shaanxi and most of the western regions is severe. The ARIMA model is suitable for forecasting the incidence of short-term dysentery. And our analysis may help prevent and control the incidence of dysentery in China.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of Oncomelania hupensis hupensis of niclosamide, and exploring the main influencing factors.</p><p><b>METHODS</b>The samples of Oncomelania hupensis hupensis were collected from 37 sampling sites in 33 counties of 10 provinces by means of stratified random sampling methods in accordance with the categories of Oncomelania hupensis hupensis habitats. Samples were randomly located into study group and control group. Oncomelania hupensis hupensis of the study group was marinated in different concentration liquor of niclosamide which was confected with water for 24 hours or 48 hours, then LC50 of niclosamide by which Oncomelania hupensis hupensis was killed and amount calculated. The influencing factors of the mortality of Oncomelania hupensis hupensis in the study group was statistically analyzed by 2 test and by multiple logistic regression using SPSS 13.0 statistical software.</p><p><b>RESULTS</b>The mortality of Oncomelania hupensis hupensis of the two test groups which were marinated in 0.5 mg/L liquor for 48 hours and 1.0 mg/L liquor for 24 hours was 100%. The effect of Oncomelania hupensis hupensis killed by niclosamide was markedly reduced along with the reduction of drug concentration. The average LC50 rates of niclosamide liquor by which Oncomelania hupensis hupensis killed for the 24 hours and 48 hours in the study group, were 0.0939 mg/L and 0.0625 mg/L, respectively. There was significant difference between the two test groups (chi(2) = 5.001, P <0.01) . In determinate range of concentration, the mortality of Oncomelania hupensis hupensis showed significant difference among the geographic types of habitat ( chi(2) = 4.264, P < 0.05). By means of multiple logistic regression using SPSS 13.0 statistical software, the estimate value of coefficient of regression on the influence factors, drug concentration, test time and the geographic types of habitat were 2. 047 ( OR = 5. 573), 0.263 ( OR = 2.924) and 0. 187- 0.210 ( OR = 1.969- 2. 560), respectively.</p><p><b>CONCLUSION</b>Niclosamide could kill Oncomelania hupensis hupensis effectively. The main influencing factors on the efficacy of niclosamide by which Oncomelania hupensis hupensis was killed, appeared to be drug concentration, time of testing and the geographic types of habitat.</p>