Figure 6.19 Pneumonia and influenza mortality in the United States, 2007–11. (A) The percentage of all deaths due to pneumonia and influenza in 122 US cities is plotted against the US national seasonal influenza baseline and the 95% confidence band above which epidemics (shaded) are declared. While the 2009–10 season in the round does not appear exceptional compared with adjacent seasons, especially 2008, the epidemic of swine flu in the fall of 2009 stands out as the largest autumn influenza event in this time series. (B) Number of influenza-related paediatric deaths. The high infant mortality during the swine flu season as compared with normal seasonal influenza in adjacent seasons is evident.

Source: Data from US Centers for Diseases Control, Influenza Division, available from http://www.cdc.gov/flu/weekly/