Preliminary Study On Forecasting And Early Warning For The Spermophilus Dauricus Focus In China

Plague is a deadly infectious disease which not only poses a formidable threat to public health, but also heavily damage on the overall economic and social development, when its occurrence and epidemic. With the aim to early detect unusual condition of infectious disease, the forecasting and early warning technology is a new method for saving time to control infectious disease outbreak and epidemic, which is becoming the hot research field. But the study on forecasting and early warning technology is underway in China.With a long history of plague epidemics, many kinds and large area of focus, it is very necessary for the study on the forecasting and early warning technology in China. The Spermophilus Dauricus Focus is found very early in China. Through two pandemics in northeast of China, the epidemics is significantly weak in recent years, but the outbreak risk of animal and human plague is still existent.Matlab was utilized and the methods of best subsets regression and exponential smoothing were employed to develop and evaluate a model for risk classification, forecasting and early warning of plague epidemics within the spermophilus dauricus Focus and6national sentinels, namely the ZhaLuTeQi, KeYouZhongQi, ZhengBaiQiWuNingBaTu, JianPing, ZhenLai and HarBin upon the Inner Mongolia surveillance data. The model involves7risk factors, including density of spermophilus dauricus, percentage of hosts infested, host flea index, percentage of nests infested, nest flea index, percentage of runways infested, and runway flea index. The forecasting values of the classification model were calculated and grouped into3risk levels, with values over2/3indicating potential epidemics, those below1/3for no epidemics, and those in between for high risk. And for each year during the observation in the spermophilus dauricus foci in Inner Mongolia, detection of Yersinia pestis gives a risk rating value of1which stands for existing epidemics, while no detection generates a zero for no epidemic activity. Then the calculated forecasting values were compared against the designated epidemics rating values. It was found that, as long as the first4of the total7risk factors were included in the model, the classification achieved overall consistent results among different combinations of risk factor selection. When forecasting values over2/3were obtained, all combinations of risk factor selection achieved consistency rates of100%. When forecasting values fell below1/3, all combinations with at least the first4factors also achieved consistency rates of100%. When forecasting values fell in between, all combinations with at least the first4factors achieved consistency rates around50%. The overall plague epidemics forecasting for2012in the spermophilus dauricus foci in inner Mongolia was no plague activity. In addition, surveillance data from the6national sentinels within the spermophilus dauricus foci in China were also collected and used to evaluate the effectiveness of the developed model. The plague epidemics forecasting upon the data from the national sentinels also indicated no plague activity in2012in the spermophilus dauricus foci. All these forecasts are consistent with the actual2012plague activities in the concerned foci, with no Yersinia pestis detected and only one specimen positive in blood coagulation testing.