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 infection 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-August 20, 2009, medical examiners and local and state health departments submitted specimens to CDC from 77 U.S. patients with fatal cases of confirmed 2009 pandemic influenza A (H1N1). This report summarizes the demographic and clinical findings from these cases and the laboratory evaluation of the specimens. Evidence of concurrent bacterial infection was found in specimens from 22 (29%) of the 77 patients, including 10 caused by Streptococcus pneumoniae (pneumococcus). Duration of illness was available for 17 of the 22 patients; median duration was 6 days (range: 1-25 days). Fourteen of 18 patients for whom information was available sought medical care while ill, and eight (44%) were hospitalized. These findings confirm that bacterial lung infections are occurring among patients with fatal cases of 2009 pandemic influenza A (H1N1) and underscore both the importance of pneumococcal vaccination for persons at increased risk for pneumococcal pneumonia and the need for early recognition of bacterial pneumonia in persons with influenza.
D000293:Adolescent; D000328:Adult; D001344:Autopsy; D001424:Bacterial Infections / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006193:Haemophilus influenzae / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications* / Q000401:mortality; D008168:Lung / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D016133:Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000235:genetics / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology