CT onset of influenza A (H1N1) complicated with severe pneumonia in two typical cases.

The novel influenza A (H1N1) virus developed in the United States and Mexico in April 2009 and has spread worldwide rapidly. Pulmonary complications are major reason of death associated with influenza A (H1N1) infection. Thus, it is necessary to investigate characteristics on the turnover of A (H1N1) infection complicated with pneumonia. Although the chest radiographic findings of the influenza A (H1N1) pneumonia were described in a clinical report, the CT findings involving turnover of influenza A (H1N1) complicated with severe pneumonia have not yet been reported. We report two typical cases of novel influenza A (H1N1) pneumonia with chest CT findings and investigate features and turnover of influenza A(H1N1) pneumonia. From the CT appearance of two cases, we found that influenza A(H1N1) complicated with pneumonia might progress rapidly, but it would recover in two or three weeks once it was controlled effectively. The CT images in our report might help the clinician to clearly understand the patterns of onset, progression and outcomes in influenza A(H1N1) complicated with pneumonia.