Spatial-temporal Distribution And Risk Factors Of Human Rabies In Yunnan Province

Rabies is a worldwide-distributed zoonotic disease caused by rabies virus(RABV).It has a case fatality rate of 100%and causes almost 60,000human fatalities each year.Human rabies is a public health problem in China,especially in less developed areas where rabies is under-reported due to a lack of epidemiological surveys.To better control human rabies,we collected human rabies and geo-environmental data in Yunnan Province,China,between 1976 and 2016.The spatial and temporal distribution of human rabies in Yunnan Province from 1976 to 2016 was analyzed by the basic methods in spatial epidemiology such as descriptive epidemiological analysis,spatial analysis,statistical analysis of spatial-temporal scanning,and spatial autocorrelation analysis.Using statistical mapping techniques,we correlated occurrences of human rabies to environmental(elevation,precipitation,Normalized Difference Vegetation Index-NDVI,temperature,and distance to the nearest main rivers)and anthropogenic(human and dog population density,distance to the nearest main roads,Gross Domestic Product-GDP)factors.The relationship between these factors and human rabies was analyzed and the risk of human rabies was predicted.The main findings were as follows:(1)Spatial and temporal distribution of human rabies in Yunnan Province,between 1976 and 2016.As for as population characteristics,the number of human rabies cases in males was significantly higher than that in females.Farmers were at the most risk for human rabies,and human rabies cases were concentrated in the age of 20-49 years old.On the time scale,there was a significant cluster with a time span from 1985 to 1989,the incidence of human rabies in summers were high.On the space scale,the occurrence of human rabies was mainly concentrated in the southeast and northeast regions of Yunnan Province,but there was a shift in space.(2)The influencing factors of human rabies in Yunnan Province.In this paper,the BRT(Boosted Regression Tree)models were constructed to analyze the influencing factors of human rabies.The results showed that environmental factors were more strongly associated than anthropogenic factors to human rabies occurrences.(3)The risk prediction of Yunnan Province.The BRT models were built to predict the risk of human rabies.We used a performance score,the average area under the receiver operator characteristic curve(AUC),to validate our risk model.The results showed that the prediction performance of the BRT model is better and the accuracy is high(AUC=0.88).The results showed that areas with elevation below 2000 meters,human population density between 30-300 people/km~2,GDP per capita between?5,000–?30,000/year,and NDVI below 0.07 were associated with greater risk for human rabies occurrence.Human rabies control in Yunnan Province should specifically target these areas.Based on the analysis of the spatial and temporal distribution of human rabies,this paper further analyzes the influencing factors of human rabies and predict human rabies risk using models.It can provide scientific theoretical support for the formulation of public health measures and strategies,which is beneficial to protect the health and safety of the population.