Spatial correlation of incidence rate of typical notifiable infectious diseases in China

  Objective  To analyze spatial distribution characteristics and spatial correlation of incidence rate of typical notifiable infectious diseases (hepatitis A, hepatitis B, hepatitis C, hepatitis D, tuberculosis, syphilis), and to provide a basis for formulating regional prevention and control measures.

  Methods  We collected the data on incidence rates and cases of hepatitis A, hepatitis B, hepatitis C, hepatitis D, tuberculosis, and syphilis between 2012 and 2014 from Health and Family Planning Yearbook of China and Annual National Report on Notifiable Infectious Diseases issued by National Health and Family Planning Commission of People's Republic of China. Hierarchical map was used to display the incidence rates of the infectious diseases in 2014 and global and local spatial autocorrelation were used to identify the spatial correlation and spatial cluster features of the rates in 2014.

  Results  During the 3-year period, the incidence of hepatitis A first decreased then increased;the incidence of hepatitis B and pulmonary tuberculosis declined obviously; and the incidence of hepatitis C, syphilis and hepatitis E showed a trend of fluctuation. The results of global spatial autocorrelation revealed the strongest spatial correlation (Moran’s I = 0.437) in the incidence of pulmonary tuberculosis and the weakest in that of syphilis (Moran’s I = 0.086); while the correlation intensity of the four types of hepatitis was not quite different, with their Moran’s I ranging from 0.23 to 0.29. The results of local spatial autocorrelation showed that the incidence of hepatitis A and pulmonary tuberculosis showed a high-high cluster feature in Xinjiang Uygur Autonomous Region, Qinghai province, and Tibet Autonomous Region; the incidence of hepatitis C showed a high-high cluster feature in Gansu province; the incidence of hepatitis E presented a high-high cluster feature in Zhejiang, Hunan and Anhui province, but a high-low cluster feature in Shanxi and Liaoning province.

  Conclusion  From 2012 to 2014, the incidence of pulmonary tuberculosis showed the strongest spatial correlation, while the incidence of syphilis showed the weakest in China. The government agencies should formulate regional prevention and control measures based on the spatial distribution characteristics of the infectious diseases and pay special attention to the prevention of specific diseases in low incidence areas around the high incidence areas.