US data on influenza deaths are a mess. The Centers for Disease Control and Prevention (CDC) acknowledges a difference between flu death and flu associated death yet uses the terms interchangeably. There are significant statistical incompatibilities between official estimates and national vital statistics data. Compounding these problems is a marketing of fear - a CDC communications strategy in which medical experts "predict dire outcomes" during flu seasons. The CDC website states what has become commonly accepted and widely reported in the lay and scientific press: annually "about 36,000 [Americans] die from flu" and "influenza/pneumonia" is the seventh leading cause of death in the United States. But why are flu and pneumonia bundled together? David Rosenthal, director of Harvard University Health Services, said, "People don't necessarily die, per se, of the [flu] virus. What they die of is a secondary pneumonia. So many of these pneumonias are not viral pneumonias but secondary [pneumonias]." In a written statement, CDC media relations responded to the diverse statistics: "Typically, influenza causes death when the infection leads to severe medical complications." Most such cases "are never tested for virus infection. The CDC uses indirect modelling methods to estimate the number of deaths associated with influenza." Thus the much publicized figure of 36,000 is ... an estimate generated by a model.