title: Factors predicting childhood respiratory syncytial virus severity: what they indicate about pathogenesis.
abstract: BACKGROUND
  A plethora of clinical experience exists defining the factors associated with differences in severity of childhood respiratory syncytial virus (RSV) infections. These clinical severity factors reveal a wealth of information about the pathogenesis of this disease. Reviewing and interpreting the clinical risk factors to gain an insight into RSV pathogenesis is important, especially considering the relative lack of parallel between many animal models of RSV infection and observed human disease.
  
  
  METHODS
  Existing and unpublished data on severity risk factors are reviewed and placed into a working pathogenesis model.
  
  
  RESULTS
  Important factors discussed are: (1) the critical role of the timing of the infection; (2) its rapidity of progression to involve the lower respiratory tract; (3) factors limiting this spread; (4) the nature of the pathogenic immune response; and (5) the host genetic and other factors that alter this immune response.
  
  
  CONCLUSIONS
  Pending new data involving these and other processes will more fully illuminate the spectrum of childhood RSV disease.
authors.affiliation: Department of Pediatrics, University of Tennessee School of Medicine, Memphis, TN, USA. Jdevincenzo@utmem.edu
authors.forename: John P
authors.initials: JP
authors.lastname: DeVincenzo
mesh_terms: D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics / Q000276:immunology / Q000503:physiopathology* / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000472:pathogenicity*; D012307:Risk Factors; D012720:Severity of Illness Index