Bacterial Coinfections in Lung Tissue Specimens From Fatal Cases of 2009 Pandemic Influenza A (H1N1)—United States, May-August 2009

In previous influenza pandemics, studies of autopsy specimens have shown that most deaths attributed to influenza A virus occurred concurrently with bacterial pneumonia, but such evidence has been lacking for 2009 pandemic influenza A (H1N1). To help determine the role of bacterial coinfection in the current influenza pandemic, CDC examined postmortem lung specimens from patients with fatal cases of 2009 pandemic influenza A (H1N1) for bacterial causes of pneumonia. During May 1-Aug 20, 2009, medical examiners and local and state health departments submitted specimens to CDC from 77 US patients with fatal cases of confirmed 2009 pandemic influenza A (H1N1). Here, a report that summarizes the demographic and clinical findings from these cases and the laboratory evaluation of the specimens is presented.