Myocardial injury and bacterial pneumonia contribute to the pathogenesis of fatal influenza B virus infection

J Infect Dis. 2012 Mar 15;205(6):895-905. doi: 10.1093/infdis/jir861. Epub 2012 Jan 30.

Abstract

Background: Influenza B virus infection causes rates of hospitalization and influenza-associated pneumonia similar to seasonal influenza A virus infection and accounts for a substantial percentage of all influenza-related hospitalizations and deaths among those aged <18 years; however, the pathogenesis of fatal influenza B virus infection is poorly described.

Methods: Tissue samples obtained at autopsy from 45 case patients with fatal influenza B virus infection were evaluated by light microscopy and immunohistochemical assays for influenza B virus, various bacterial pathogens, and complement components C4d and C9, to identify the cellular tropism of influenza B virus, characterize concomitant bacterial pneumonia, and describe the spectrum of cardiopulmonary injury.

Results: Viral antigens were localized to ciliated respiratory epithelium and cells of submucosal glands and ducts. Concomitant bacterial pneumonia, caused predominantly by Staphylococcus aureus, was identified in 38% of case patients and occurred with significantly greater frequency in those aged >18 years. Pathologic evidence of myocardial injury was identified in 69% of case patients for whom cardiac tissue samples were available for examination, predominantly in case patients aged <18 years.

Conclusions: Our findings suggest that bacterial pneumonia and cardiac injury contribute to fatal outcomes after infection with influenza B virus and that the frequency of these manifestations may be age related.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Antigens, Viral / analysis
  • Antigens, Viral / immunology
  • Autopsy
  • Child
  • Child, Preschool
  • Cohort Studies
  • Female
  • Heart Injuries / complications
  • Heart Injuries / microbiology
  • Heart Injuries / pathology*
  • Heart Injuries / virology
  • Hospitalization
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza B virus / pathogenicity*
  • Influenza, Human / complications
  • Influenza, Human / microbiology*
  • Influenza, Human / mortality*
  • Influenza, Human / pathology
  • Male
  • Middle Aged
  • Myocardium / pathology*
  • Pneumonia, Bacterial / complications
  • Pneumonia, Bacterial / pathology*
  • Specimen Handling
  • Staphylococcus aureus / pathogenicity
  • Viral Tropism
  • Young Adult

Substances

  • Antigens, Viral