Characteristics and demographics of patients presenting with pandemic influenza A (pH1N1) compared to other respiratory viruses.

aOdds ratios for age categories are compared to individuals bCongenital malformations, asthma, chronic obstructive pulmonary disease (COPD), chronic lung disease, previous serious or multiple lung infection/disease/intubation, cystic fibrosis, history of reactive airway disease or wheezing;cCirrhosis, end-stage liver disease, hepatitis, congenital abnormalities;dChronic kidney disease, end-stage renal disease, congenital disease, nephrotic syndrome, transplant recipient; Malignancy = leukemia, bladder, breast, head and neck, lung, lymphoma, medulloblastoma, prostate, multiple myeloma, neuroblastoma, ovarian, sarcoma;eSeizure disorder, dementia, developmental delay, cerebral palsy, stroke, congenital, neuromuscular, trauma/surgery; Cardiac disease = arrhythmia, coronary artery disease, heart failure, congenital, valvular disease, cardiomyopathy, myocardial infarction;fHuman Immunodeficiency Virus;gSystemic steroid use, transplant recipient, chemotherapy, human immunodeficiency virus (HIV).