Exact numbers of how many people died from flu this season cannot be determined. Flu-associated deaths (which have laboratory confirmed influenza), are only a nationally notifiable condition among children; however not all pediatric influenza deaths may be detected and reported and there is no requirement to report adult deaths from influenza. In addition, many people who die from flu complications are not tested, or they seek medical care later in their illness when flu can no longer be detected from respiratory samples. However, CDC tracks pneumonia and influenza (P&I) deaths through the 122 Cities Mortality Reporting System. This system collects information each week on the total number of death certificates filed in each of the 122 participating cities and the number of death certificates with pneumonia or influenza listed as a cause of death. The 122 Cities Mortality Reporting system helps gauge the severity of a flu season compared with other years. However, only a proportion of all P&I deaths are influenza-related and, as noted, most flu deaths are not lab confirmed. Thus, this system does not allow for an estimation of the number of deaths, only the relative severity among different influenza seasons. For the 2007-08 season, the proportion of deaths due to pneumonia and influenza was higher than the previous two years, but was similar to the 2004-05 season.
(Note: The counts above are of flu-associated deaths among children according to the flu season the deaths occur, not when they are reported to CDC.)