Comparison of clinical characteristics between persons with fatal influenza A(H5N1) virus infection and fatal human influenza virus infection.

N/a: not applicable;*unadjusted OR and 95% CI of a fatal H5N1 outcome versus a fatal human influenza outcome;†dyspnea: defined as any recorded difficulty breathing or shortness of breath in any age group, or in a child less than age 5, the presence of stridor or chest in-drawing;§altered mental status: defined as any recorded presence of altered mental status, confusion, or unconsciousness;¶pneumonia: defined as the presence of alveolar infiltrates, interstitial infiltrates, or lobar consolidation on chest X-ray;**not possible to calculate an unadjusted OR.