Risk factors for severe complications of the novel influenza A (H1N1): analysis of patients hospitalized in Italy.

Eighty-one patients affected by the novel influenza A (H1N1), hospitalized in North-western Italy, were studied. The median age was 32 years (range 1-81 years). Fifty-six (69%) had an underlying medical condition, including lung disorders (asthma or chronic obstructive pulmonary disease) in 34% and obesity in 25%. Fifty percent of them had pneumonia, 12% were admitted to the intensive care unit and 3% died. Antiviral treatment was initiated in 75% of patients started within 48 h. Older age and lung and neurocognitive disorders were associated with severe disease and death.