Investigation of space-time clusters and geospatial hot spots for the occurrence of tuberculosis in Beijing

OBJECTIVE: To characterise the geographic and spatiotemporal distribution of confirmed tuberculosis (TB) cases in Beijing between 2005 and 2009. DESIGN: The yearly notification rate maps were used to describe the distribution of confirmed adult TB patients. Spatial autocorrelation (Moran's I ) and hot-spot analysis were adopted to detect the clusters and hot spots of TB. RESULTS: The TB incidence rate (cases per 100 000 population) in Beijing increased from 29.8 in 2005 to 35.0 in 2009. The incidence rate was significantly higher in the Urban Development New District and the Ecologic Reservation Development District (>30/100 000) than in the other districts. There was a significant spatial autocorrelation throughout the city (u = 2.58, P = 0.01). Evident clusters were observed in the Capital Functional Core District and the Urban Function Extension District (Gi*> 1). CONCLUSION: Spatial autocorrelation and hot-spot analysis may serve as efficient tools to detect space-time clusters and geospatial hot spots of TB incidence. Between 2005 and 2009, TB incidence in Beijing showed population density and mobility-dependent and ecos ocial status-dependent space-time clusters and geospatial hot spots.