Spatial epidemiology of an H3N2 swine influenza outbreak.

The H3N2 swine influenza virus appeared for the 1st time in the province of Manitoba during the fall of 2004. The purpose of this study was to characterize how swine influenza moved through the province in time and space, and to determine if there are any significant patterns associated with this movement. Herds with outbreaks of H3N2 swine influenza were located by using a Geographic Information System and analyzed by using spatial analysis software. Descriptive and spatial statistics, including the Nearest Neighbor Index, Cuzick and Edwards' test, Spatial Scan statistic, k Nearest Neighbor test, Knox's test, and Mantel's test, were used to analyze the outbreak. There was clustering of the outbreak in the region surrounding Steinbach, Manitoba, an area that is densely populated with swine. It is hypothesized that density of swine farms was a factor in the clustering and movement of this swine influenza outbreak.