title: Molecular characteristics of outbreaks of nosocomial infection with influenza A/H3N2 virus variants.
abstract: OBJECTIVE
  To describe outbreaks of nosocomial influenza infection with molecular methods and to elucidate the viral linkages among outbreak case patients including both inpatients and healthcare workers (HCWs).
  
  
  METHODS
  A 180-bed acute and long-term care hospital in Japan.
  
  
  METHODS
  Retrospective observational study of nosocomial outbreaks of infection with influenza A/H3N2. Together with information about onset dates and vaccination history, we obtained nasopharyngeal swab samples from individuals with cases of influenza or influenza-like illness (ILI). The hemagglutinin genes of the recovered viruses were sequenced and compared, along with those of community-circulating strains, for similarity by phylogenetic tree analysis.
  
  
  RESULTS
  The outbreaks occurred from February 26 through April 3, 2007, during the 2006-2007 epidemic season, and they involved 11 patients and 13 HCWs. The 2 outbreaks involved 2 different genotypes of influenza A/H3N2 viruses. These virus variants were closely related to the influenza strains that were circulating in the community during the same epidemic season.
  
  
  CONCLUSIONS
  This study showed the dissemination of highly homologous influenza virus variants among inpatients and HCWs within a short period, as a result of nosocomial transmission. These strains were also similar to influenza strains that were circulating in the community.
authors: Division of Public Health, Department of Infectious Disease Control and International Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan. t-oguma@med.niigata-u.ac.jp
authors: Taeko
authors: T
authors: Oguma
authors: Reiko
authors: R
authors: Saito
authors: Hironori
authors: H
authors: Masaki
authors: Kazuhiko
authors: K
authors: Hoshino
authors: Hassan
authors: H
authors: Zaraket
authors: Yasushi
authors: Y
authors: Suzuki
authors: Isolde
authors: I
authors: Caperig-Dapat
authors: Clyde
authors: C
authors: Dapat
authors: Tatiana
authors: T
authors: Baranovich
authors: Reiki
authors: R
authors: Kuroki
authors: Yasushi
authors: Y
authors: Makimoto
authors: Yutaka
authors: Y
authors: Shirahige
authors: Norichika
authors: N
authors: Asoh
authors: Satoshi
authors: S
authors: Degawa
authors: Hidefumi
authors: H
authors: Ishikawa
authors: Hironobu
authors: H
authors: Kageura
authors: Maki
authors: M
authors: Hosoi
authors: Hiroshi
authors: H
authors: Suzuki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015373:Bacterial Typing Techniques; D003428:Cross Infection / Q000453:epidemiology / Q000821:virology*; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D005260:Female; D006389:Hemagglutinins, Viral / Q000235:genetics; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D012189:Retrospective Studies; D017423:Sequence Analysis, RNA
chemical_list: D006389:Hemagglutinins, Viral; D012367:RNA, Viral