Spatial distribution characteristics and correlation of human and livestock brucellosis in mainland China,2006-2012

ObjectiveTo explore the spatial distribution characteristics and correlation of human and livestock brucellosis in mainland China from 2006 to 2012,and to provide references for taking corresponding control measures.MethodsHuman brucellosis data were extracted from the database of reported notifiable infectious diseases in China published by China Public Health Science Data Center and the livestock brucellosis data from Official Veterinary Bulletin issued by Ministry of Agriculture of China.Global and local spatial autocorrelation analyses were carried out based on the data for the years of 2006 to 2012.ResultsThe overall incidence of human brucellosis increased from 1.45/100 000 to 2.93/100 000 during the period and the global Moran's I coefficients for the incidence ranged from 0.179 0 to 0.345 8 and were all positive(all P<0.05),suggesting a significant spatial clustering of the incidence; the number of livestock brucellosis increased from 2 032 to 82 071 during the same period,with the global Moran's I coefficients of 0.164 3,-0.072 8,and -0.083 3(all P<0.05)for the year of 2010,2011,and 2012.Both univariate and bivariate local spatial autocorrelation analysis showed a positive correlation between human and livestock brucellosis.The areas with high clustering of human brucellosis were observed in agricultural and pastoral regions in northern of China and the areas with low clustering in non-agricultural and non-pastoral regions in southern of China.ConclusionHuman and livestock brucellosis present different patterns of spatial clustering; the degree of human brucellosis spatial clustering increases yearly,while the distribution of livestock brucellosis cases is not consistent to that of spatial autocorrelation coefficients of the diseases.