[Clinical features and outcome in 84 patients with influenza pneumonia]

We examined the clinical features, illness types of pneumonia, efficacy of neuraminidase inhibitors and outcome in patients with influenza pneumonia. Eighty-four patients with influenza pneumonia, in whom the diagnosis was confirmed by serology or rapid diagnostic tests, were studied. Because neuraminidase inhibitors were given prior to the onset of pneumonia in some patients with secondary bacterial pneumonia, we examined the efficacy of neuraminidase inhibitors in patients other than the secondary bacterial pneumonia group. Influenza A was detected in 71% of the subjects, and influenza B in 29% who showed a clinical presentation and outcome similar to those patients with influenza A. Primary influenza viral pneumonia was observed in 27% of the subjects, mixed viral and bacterial pneumonia in 38%, secondary bacterial pneumonia in 18%, and unclassified type of pneumonia in 17%, respectively. Eighty-three percent of the subjects had underlying diseases. The overall mortality rate was 9.5%, and all 8 fatal cases had comorbidities. Thirty-nine percent were aged under 65 years and 3 fatal cases were aged under 65 years. The mortality rates of patients receiving or not receiving neuraminidase inhibitor were 4.9% and 14.3%, respectively. Due to the small number of patients and the fact that this case was not a controlled study, the efficacy of neuraminidase inhibitors for influenza pneumonia was not proved.