Ultrasound findings of lung consolidation with sonographic air bronchograms [6, 7, 16] correlated 100% with chest X-ray findings of bacterial pneumonia (reported as consolidation or infiltrate) in eight patients. All of these patients were confirmed to have pneumonia based on the clinical course at 2-week follow-up. This represented a doubling (40% vs. 20%) in the prevalence rate of bacterial pneumonia in our study during the H1N1influenza A onset and surge time period compared to the time period prior to the onset of H1N1 influenza A. The prevalence of viral lung ultrasound findings increased from approximately 50% for the overall study [13] to 75% during the surge of H1N1 influenza. Chest X-ray findings for viral pneumonia (most commonly described as peri-bronchial thickening or peri-bronchial cuffing) were present in 8 of 15 (53%) patients identified as having viral pneumonia on ultrasound. Seven of these 15 patients with viral pneumonia based on ultrasound had superimposed bacterial pneumonia also identified by ultrasound (Figure 7 and Additional file 4). All four patients in our series that required hospitalization had viral and bacterial pneumonia based on ultrasound.