title: Human respiratory syncytial virus (hRSV) RNA quantification in nasopharyngeal secretions identifies the hRSV etiologic role in acute respiratory tract infections of hospitalized infants.
abstract: BACKGROUND
  Human respiratory syncytial virus (hRSV) detection in nasopharyngeal aspirates (NPAs) from infants with acute respiratory tract infection (ARTI) does not prove the hRSV etiology of the current ARTI episode. HRSV RNA quantification may help in affording this issue.
  
  
  OBJECTIVE
  hRSV was detected by quantitative reverse transcription-PCR in NPAs taken upon admission to hospital and, whenever possible, at discharge and subsequent medical visits.
  
  
  METHODS
  Prospective study, including 63 infants affected by either hRSV upper or lower ARTI.
  
  
  RESULTS
  Based on the kinetics of viral load, hRSV etiology was identified in 25 infants in whom hRSV load dropped from 2.5 x 10(6) upon admission (presence of respiratory symptoms) to 7.5 x 10(2)RNAcopies/ml NPA upon discharge (absence of symptoms) after a median time of 5 days, and in 19 infants, in whom hRSV load was determined at admission only, in association with clinical symptoms (2.4 x 10(6)copies/ml). Furthermore, low levels of hRSV RNA (<1 x 10(5)copies/ml NPA) identified 14 patients with non-hRSV ARTI. Finally, in 14 infants with hRSV coinfections or sequential infections, hRSV quantification defined the hRSV role in the current ARTI episode.
  
  
  CONCLUSIONS
  hRSV RNA quantification is critical in defining the hRSV role in respiratory infections.
authors: Servizio di Virologia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
authors: Giulia
authors: G
authors: Campanini
authors: Elena
authors: E
authors: Percivalle
authors: Fausto
authors: F
authors: Baldanti
authors: Francesca
authors: F
authors: Rovida
authors: Alice
authors: A
authors: Bertaina
authors: Antonietta
authors: A
authors: Marchi
authors: Mauro
authors: M
authors: Stronati
authors: Giuseppe
authors: G
authors: Gerna
mesh_terms: D000208:Acute Disease; D006760:Hospitalization; D006801:Humans; D007223:Infant; D009305:Nasopharynx / Q000378:metabolism / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D012367:RNA, Viral