Pneumonia is the most frequent and severe complication of influenza, most commonly presenting in high risk patients (Table 1) . Primary influenza pneumonia represents direct lung involvement by influenza virus, and should be suspected in non-resolving influenza infections. Typically, primary influenza pneumonia presents in chest x-rays with bilateral reticular or reticulonodular opacities. Less frequently, focal areas of consolidation can be seen, particularly in the lower lobes. High-resolution computed tomography may show ground glass opacities with or without multifocal peribronchovascular and subpleural consolidation [10] .