title: Role of neutralizing antibodies in adults with community-acquired pneumonia by respiratory syncytial virus.
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) has been implicated in the etiology of adult community-acquired pneumonia (CAP). We investigated RSV infection in Chilean adults with CAP using direct viral detection, real-time reverse-transcription polymerase chain reaction (rtRT-PCR), and serology (microneutralization assay).
  
  
  METHODS
  RSV, other respiratory viruses, and bacteria were studied by conventional and molecular techniques in adults aged ≥18 years presenting with CAP to the healthcare facilities in Santiago, Chile from February 2005 through December 2007.
  
  
  RESULTS
  All 356 adults with CAP enrolled had an acute blood sample collected at enrollment, and 184 had a convalescent blood sample. RSV was detected in 48 cases (13.4%). Immunofluorescence assay and viral isolation each detected only 1 infection (0.2%), whereas rtRT-PCR was positive in 32 (8.9%) cases and serology was positive in 20 (10.8%) cases. CAP clinical characteristics were similar in RSV-infected and non-RSV-infected cases. RSV-specific geometric mean serum-neutralizing antibody titer (GMST) was significantly lower at admission in the 48 RSV-infected cases compared with 308 non-RSV-infected adults (GMST in log(2): RSV/A 8.1 vs 8.9, and RSV/B 9.3 vs 10.4; P < .02).
  
  
  CONCLUSIONS
  RSV infection is frequent in Chilean adults with CAP. Microneutralization assay was as sensitive as rtRT-PCR in detecting RSV infection and is a good adjunct assay for diagnostic research. High RSV-specific serum-neutralizing antibody levels were associated with protection against common and severe infection. The development of a vaccine could prevent RSV-related CAP in adults.
authors.affiliation: Programa de Virología, Facultad de Medicina, Universidad de Chile, Santiago, Chile. vluchsin@med.uchile.cl
authors.forename: Vivian
authors.initials: V
authors.lastname: Luchsinger
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Piedra
authors.forename: Mauricio
authors.initials: M
authors.lastname: Ruiz
authors.forename: Enna
authors.initials: E
authors.lastname: Zunino
authors.forename: María Angélica
authors.initials: MA
authors.lastname: Martínez
authors.forename: Clarisse
authors.initials: C
authors.lastname: Machado
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Fasce
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Ulloa
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Fink
authors.forename: Pamela
authors.initials: P
authors.lastname: Lara
authors.forename: Luis F
authors.initials: LF
authors.lastname: Avendaño
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D057134:Antibodies, Neutralizing / Q000097:blood* / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D002677:Chile / Q000453:epidemiology; D019411:Clinical Laboratory Techniques / Q000379:methods; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests / Q000379:methods; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral